N-perylenyl phenoxazine and fluorene-based conjugated copolymer as a potential fluorescent probe for nitroaromatic explosives detection

N-perylenyl phenoxazine and fluorene-based conjugated copolymer as a potential fluorescent probe for nitroaromatic explosives detection | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article N-perylenyl phenoxazine and fluorene-based conjugated copolymer as a potential fluorescent probe for nitroaromatic explosives detection Luan Thanh Nguyen, Thanh Tien Nguyen, Minh Duy Hoang, Tam Hoang Luu, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7460772/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 10 Nov, 2025 Read the published version in Journal of Polymer Research → Version 1 posted 5 You are reading this latest preprint version Abstract The detection and discrimination of nitroaromatic compounds (NACs) are crucial for ensuring environmental safety and national security. Compounds like Picric acid (PA) and its derivatives are primarily released into the environment through coal mining activities, military activities, and various industrial chemical synthesis processes. These substances not only contribute significantly to the pollution of soil, water, and air, but they also pose serious risks to human health and living organisms due to their potential to cause mutations and cancer. In this research, we synthesized two conjugated polymers based on phenoxazine bearing perylene as a side chain and benzo[c][ 1 , 2 , 5 ]thiadiazole with fluorene backbone as co-monomers, and developed an efficient fluorescence sensor employing them. This work presents a novel approach for tracing nitroaromatic compounds, including 2,4,6-trinitrotoluene (TNT), 2,4-Dinitrotoluene (DNT), Nitrobenzene (NB), 4-Nitrophenol (NP), and PA. Conjugated polymer Phenoxazine Perylene Fluorene Aerobic polycondensation Picric acid detection Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 1. Introduction The nitroaromatic compounds (NACs) are recognized for their toxicity and explosive characteristics, posing significant risks to both human health and aquatic ecosystems [ 1 – 3 ]. Among explosive compounds, the 2,4,6-trinitrotoluene (TNT), Picric acid (PA, as known 2,4,6-trinitrophenol), 2,4-dinitrotoluene (DNT), and 2,4-dinitrophenol (DNP) are particularly notable due to their strong explosive characteristics, commonly utilized in industries such as mining, fireworks, and gunpowder manufacturing [ 4 ]. Therefore, significant amounts of these explosive compounds have been released into the environment, leading to serious health consequences for humans, including symptoms such as vomiting, lung cancer, convulsions, and so on [ 5 ]. To date, various methods have been developed to detect the explosive compounds in soil, water sources, and industrial waste, including high-performance liquid chromatography, spectroscopy, and electrochemistry [ 6 – 8 ]. While these techniques can identify the explosive compounds in nano/micro-scale amounts, they require state-of-the-art instruments that necessitate maintenance and involve complex operation systems. Recent advancements in the field of chemsensing have focused on the utilization of sensitive fluorescent materials as chemosensors for the detection of explosive compounds [ 2 , 9 , 10 ]. These materials enhance optical signals through various fluorescence mechanisms, including photo-induced electron transfer (PET), fluorescence resonance energy transfer (FRET), electron exchange, and intermolecular charge transfer (ICT) [ 2 ]. However, achieving high sensitivity and selectivity remains a significant challenge, particularly for the detection of the analytes at very low concentrations. To address this challenge, a range of fluorescent materials has been developed, including quantum dots (QDs) [ 11 ], metal-organic frameworks (MOFs) [ 12 , 13 ], porous organic polymers (POPs) [ 14 ], small molecules and fluorescent polymers [ 15 ]. Among these, conjugated polymers have garnered extensive research interest due to their straightforward synthetic procedures, good chemical stability, and robust optical emission properties [ 16 ]. In addition, the structural design of conjugated fluorescent polymers can be tailored to enhance their electron donor capacity via delocalized π* excited states, thereby facilitating a molecular wire effect that amplifies interactions with explosive analytes [ 1 , 16 , 17 ]. For instance, Eddin et. al synthesized five random copolymers based on styrene, incorporating various fluorophore pendant groups such as pyrene, naphthalene, phenanthrene, and triphenylamine as semi-conjugated polymers for the detection of nitroaromatic compounds [ 18 ]. These copolymers exhibited absolute quantum yields as high as 0.93 in the solid state, depending on their fluorophore composition, with the detection limits ranging from 10 − 6 to 10 − 7 mol L − 1 for nitroaromatics in dichloromethane solution. More recently, Liu et. al reported the synthesis of fluorescent conjugated polymers derived from 1,6-dibromopyrene and 9,9-dioctyl-2,7-dibromofluorene. Their approach employs linkages involving both “single bond” and “alkyne bond” chemistry, resulting in the limit of detections (LOD) of these conjugated polymers for liquid-phase TNT below 2.0 µM [ 19 ]. In 2023, Haque introduced two rigid types of conjugated poly(dioctaloxybenzenesilole) that incorporated octyloxybenzene subunits, namely, 1,1-dibutyl-3,4-diphenylbis(2,5-bis(octaloxy)benzene)-2,5-polysilole and 1,1-dibutyl-3,4-diphenyltris(2,5-bis(octaloxy)benzene)-2,5-polysilole, synthesized through an intricate series of steps. The resulting materials exhibited the quenching of fluorescence at a concentration of 217 µM TNT in the liquid state [ 20 ]. The structural design of fluorescent conjugated polymers is pivotal in leveraging their sensing performance for tracing of explosive compounds, yet the synthesis procedure of such polymers poses a great challenge [ 1 – 3 ]. Achieving high purity, homogeneous structures, low polydispersity index, and satisfactory yields is essential. Traditional synthetic methodologies, including Suzuki, Heck, Stille, and Sonogashira coupling reactions, often require complicated multiple steps involving anhydrous solvents, living catalysts, and cryogenic conditions [ 21 , 22 ]. Therefore, a simplified synthesis procedure employing an efficient catalyst with high-yield reactions is necessary for producing fluorescent conjugated polymers [ 23 ]. To address this issue, aerobic polymerization emerges as the most effective method for synthesizing conjugated polymers [ 24 – 27 ]. Regarding constructive building blocks, dialkylfluorene and phenoxazine derivatives are well known as fluorescent components utilized in electrochromic and organic light-emitting diode devices [ 28 , 29 ]. In addition, the perylene unit features a large π-conjugated system that exhibits strong fluorescence, a long fluorescence lifetime, and chemical stability [ 30 ]. Moreover, the benzo[c][ 1 , 2 , 5 ]thiadiazoles are widely used in conjugated polymers, serving as favorable binding groups [ 31 ]. They help reduce steric hindrance and enhance the localization of electrons along the main chain of conjugated polymers. In this study, we synthesize new fluorescent conjugated polymers containing 10-(perylen-3-yl)-10H-phenoxazine, benzo[c][ 1 , 2 , 5 ]thiadiazole, and 9,9-dioctyl-9H-fluorene moieties within the main chain, along with perylene fluorophores in the side chain. This design aims to enhance the interaction between the CPs explosive compounds such as PA, TNT and DNT. Building upon this foundation, we perform model Suzuki polycondensation under aerobic conditions to prepare conjugated polymers featuring 9,9-dioctyl-9H-fluorene with either 10-(perylen-3-yl)-10H-phenoxazine or benzo[c][ 1 , 2 , 5 ]thiadiazole. The synthesized polymers are characterized using Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance ( 1 H NMR), and gel permeation chromatography (GPC) to determine their chemical structures. We further investigate their optical and electrical properties through ultraviolet-visible (UV-Vis) spectroscopy, fluorescence (FL) spectroscopy, reflective spectroscopy, cyclic voltammetry, and four-point measurements. Additionally, the thermal properties of polymers are characterized by differential scanning calorimetry (DSC). In order to acknowledge their practical applications, the synthesized conjugated polymers have been applied as fluorescent sensors for the detection of nitroaromatic explosives across various phases, including both solution and solid states. 2. Experimental 2.1 Materials and chemicals 4,7-dibromobenzo[c][ 1 , 2 , 5 ]thiadiazole (95%), 2,2'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) (95%), Palladium(II) acetate (98%), Tris(o-methoxyphenyl)phosphine (96%), phenooxazine (97%), sodium borohydride (NaBH 4 , 99%), triethylamine (99%), Potassium phosphate (K 3 PO 4 ) (99%) and 3-Bromoperylene (95%), were purchased from Sigma Aldrich and used as received. Tetrahydrofuran (THF) (99.5%) was purchased from Fisher and dried using molecular sieves under N 2 . Chloroform (CHCl 3 ), Toluene (99%), Dichloromethane (CH 2 Cl 2 ) (99.8%), n-heptane (99%), methanol (99%), ethyl acetate (99%), and diethyl ether (99%) were purchased from Fisher/Acros (Bridgewater, NJ, USA) and used as received. Silica gel 60 (0.063–0.200 mm) for column chromatography was purchased from Merck and used as received. 2.2 Characterization GPC measurements were carried out using a Varian Polymer PL-GPC 50 gel permeation chromatography system equipped with an RI detector and a mesopore column, employing chloroform as the eluent with a flow rate of 1.0 ml min − 1 at 30 o C. The pressure over the column was 5.7 MPa. The average molecular weight and molecular weight distribution of the obtained polymers were determined using polystyrene (PS) standards. 1 H NMR spectra were characterized on a Bruker Avance 500 MHz using deuterated chloroform (CDCl 3 ) as a solvent and tetramethylsilane as an internal reference. FT-IR spectroscopy was performed using Thermo Nicolet 6700 spectrometer, with 264 scans recorded from 400 cm − 1 to 4000 cm − 1 . UV-Vis spectroscopy of the conjugated polymers was recorded on an Agilent UV–Vis 8453 diode array spectrometer over the wavelength range of 200 nm to 1100 nm, supported by a Peltier controller. Fluorescence spectra were measured using a Varian Cary Eclipse Fluorescence Spectrometer. Fluorescence spectra of solid-state thin films were acquired using an Ocean Optics USB4000 spectrophotometer with an integrated sphere, excited by a 365 nm LED-UV wavelength. Transmission spectroscopy was performed on Ocean Optics Maya 2000 Pro spectrophotometer with an integrated sphere under visible light ranging from 400 nm to 900 nm. Microscopy spectroscopy was recorded on CRAI spectroscopy using OCEAN OPTIC SF2000 instrument with a Lumenera infinity 1 microscopy camera. Differential scanning calorimetry (DSC) analysis was performed using TA instrument 2910 under nitrogen flow with a heating rate of 10°C min − 1 from − 20 o C to 300°C. Electrochemical measurements were investigated on an AUTOLAB instrument using NOVA 1.11 software. The electrochemical experiments used an Au disc working electrode and a Pt wire counter electrode. The electrochemical solution consisted of 0.1 M TBAPF 6 in CH 3 CN, which was purged with argon for 20 minutes prior to data collection. All potentials are referenced to a Ag/Ag + reference electrode (0.1 M AgNO 3 /0.1 M TBAPF 6 in CH 3 CN; 0.320 V vs. SCE) and internally standardized with ferrocene (vs. Ag/Ag + ). E HOMO values were determined in reference to ferrocene. The polymer film was coated onto an electrode that had been washed with CH 3 CN and then placed in a cell with a fresh electrolyte solution for electrochemical characterization. A four-point probe measurement was measured on the Loresta-EP MCP - T360 Mitsubishi, featuring Peltier temperature control. 2.3 Synthesis of Poly(benzo[c][ 1 , 2 , 5 ]thiadiazole- alt -9,9-dioctyl-9H-fluorene) (Poly(BT- alt -OF)) (P1) To a dry 25 mL single neck round-bottom flask equipped with a magnetic bar, 2 mL of anhydrous toluene were added to dissolve the mixture including 70 mg of (4,7-dibromobenzo[c][ 1 , 2 , 5 ]thiadiazole) (70 mg, 0.24 mmol, 1.0 eq), 2,2'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) (147 mg, 0.24 mmol, 1.0 eq), Pd(OAc) 2 (5.3 mg, 0.024 mmol, 0.1 eq), P(o-Anisyl) 3 (8.4 mg, 0.024 mmol, 0.1 eq), K 3 PO 4 (415 mg, 1.9 mmol) under air atmosphere. An Allihn condenser with a standard lower inner drip tip 24/40 joint at the bottom was attached to the flask. Afterwards, the reaction was subjected to stirring and heating up to 120 o C using an oil bath in air at a speed of 800 rpm for 24 h. After cooling to room temperature, a solution of 5 N HCl (2 mL) was added to quench the reaction, and the mixture was extracted with toluene. The combined organic layers were washed with brine and diluted water, dried over anhydrous MgSO 4 , and the mixture was filtered and concentrated under reduced pressure. Then, the conjugated polymer was precipitated into cold methanol (100 mL) using a chiller bath. The polymer product, identified as Poly(BT- alt -OF) (designated as P1), was isolated through filtration, rinsed with additional methanol, and then dried under vacuum for 24 hours prior to further characterization. The final yield of the conjugated polymer was 94.7 mg, corresponding to an overall yield of 76.09%. 1 H NMR (500 MHz, CDCl 3 ), δ (ppm): 8.10 (t, 2H), 8.04 (d, 2H), 7.96 (d, 42H), 7.94 (d, 2H), 7.69 (d, 1H), 2.12 (s, 4H), 1.16–1.14 (s, 28H), 0.96 (s, 3H), 0.81 (m, 9H). GPC: M n = 4500 g mol − 1 . Đ (M w /M n ) = 1.85. 2.4 Synthesis of Poly(10-(perylen-3-yl)-10H-phenoxazine- alt -9,9-dioctyl-9H-fluorene) (Poly(PPO- alt -OF)) (P2) 90 mg of 3,7-dibromo-10-(perylen-2-yl)-10H-phenoxazine (0.15 mmol) and 96.3 mg (0.15 mmol) of 2,2'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) was dissolved in 2 mL of pristine reagent-grade toluene in a 100 ml round bottom flask. Then, Pd(OAc) 2 (3.36 mg, 0.015 mmol), P(o-Anisyl) 3 (5.4 mg, 0.015 mmol) and 265 mg of K 3 PO 4 were added to the reaction. Next, the flask reaction was stirred and heated up to 120 o C using an oil bath under an air atmosphere at speed of 800 rpm for 24 h. After cooling to room temperature, a solution of 5 N HCl (2 mL) was added to quenching the mixture reaction, and mixture was extracted with toluene. The combined organic layers were washed with brine and diluted water, dried over anhydrous MgSO 4 , the mixture was filtrated and concentrated under reduced pressure. Then, the conjugated polymer was precipitated in cold methanol (100 ml) using a chiller bath. The polymer product, identified as Poly(PPO- alt -OF) (designated as P2), was isolated through filtration, rinsed with additional methanol, and then dried under vacuum for 24 hours prior to further characterization. The final yield of the conjugated polymer was 91.8 mg, corresponding to an overall yield of 73.55%. 1 H NMR (500 MHz, CDCl 3 ), δ (ppm): 8.39–8.28 (m, 4H), 7.97 (s, 1H), 7.75–7.46 (m, 10H), 7.16 (s, 2H), 6.90 (d, 2H), 6.01 (d, 2H), 1.96 (s, 4H), 1.53–0.67 (m, 30H). GPC: M n = 7600 g mol − 1 . Đ (M w /M n ) = 1.55. 3. Results and discussion 3.1 Synthesis of Poly(BT- alt -OF) and Poly(PPO- alt -OF) conjugated polymers The synthesis procedure to prepare two conjugated polymers based on 9,9-dioctyl-9H-fluorene with 10-(perylen-2-yl)-10H-phenoxazine and benzo[c][ 1 , 2 , 5 ]thiadiazole was illustrated in Scheme 1 . In the initial stage, dibrominated N-perylenephenoxazine monomer was synthesized from commercially available phenoxazine and perylene via three steps in a good yield of 67% [ 32 ]. The polymer Poly(BT- alt -OF) was synthesized using 4,7-dibromobenzo[c][ 1 , 2 , 5 ]thiadiazole and 2,2'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) with 1:1 molar ratio. This polymerization was carried out via Pd-catalyzed Suzuki polycondensation under aerobic conditions, where Pd(OAc) 2 , P(o-Anisyl) 3 , and K 3 PO 4 were used as the catalyst, ligand, additive, and base, respectively. In the case of Poly(PPO- alt -OF), it was synthesized from 3,7-dibromo-10-(perylen-2-yl)-10H-phenoxazine and 2,2'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) in 1:1 molar ratio., following the same aerobic conditions of Poly(BT- alt -OF). The polymers were extracted through Soxhlet extraction with chloroform to obtain the soluble fractions, which accounted for 65.4% of Poly(BT- alt -OF) and 91.2% of Poly(PPO- alt- OF) by weight. The insoluble fractions constituted approximately 34.6% and 8.8% for Poly(BT- alt -OF) and Poly(PPO- alt- OF), respectively. The obtained conjugated polymers were characterized by GPC to determine their average molecular weights. Poly(BT- alt -OF) exhibited a number-average molecular weight (M n ) of 4500 g mol − 1 with dispersity (Đ) of 1.85, while Poly(PPO- alt- OF) showed an M n of 7600 g mol − 1 with Đ of 2.55 (Fig. 1 b). This suggests that P2 exhibits weaker π–π stacking interactions than P1 because it incorporates a nonplanar phenoxazine (PXZ) unit into its conjugated backbone [ 33 ]. The chemical structures of Poly(BT- alt -OF) and Poly(PPO- alt- OF) were characterized by FT-IR (Fig. 1 a) and 1 H NMR spectroscopies (Fig. 2 ). In the FT-IR spectrum of Poly(BT- alt -OF), a notable peak was observed at 513 cm − 1 , which is attributed to the N-S linker associated with the thiadiazole moieties. Additional peaks at 818 cm − 1 and 1260 cm − 1 correspond to the C-H and C = N of Poly(BT- alt -OF). Typical bands, from 2853 cm − 1 to 3030 cm − 1 , are assigned to the C–H stretching vibrations of the octyl groups of 9,9-dioctyl-9H-fluorene-2,7-diyl moieties. The peak recorded at 1460 cm − 1 signifies the presence of C = C aromatic bonds within the main chain of Poly(BT- alt -OF). In the FT-IR spectrum of Poly(PPO- alt- OF), the peaks at 1340 cm − 1 and 1260 cm − 1 are ascribed to the C-N and C-O bonding of phenoxazine units, respectively. The peaks in the region from 2853 cm − 1 to 3050 cm − 1 indicate C–H stretching vibrations. Overall, the FT-IR spectra of both Poly(BT- alt -OF) and Poly(PPO- alt- OF) exhibited all of their structural characteristic peaks. The analysis of the 1 H NMR spectrum of Poly(BT- alt -OF) revealed the peaks ranging from 8.04 ppm to 7.69 ppm, which correspond to the aromatic region of benzo[c][ 1 , 2 , 5 ]thiadiazole and fluorene moieties (Fig. 2 ). A multiplet observed at 2.1 ppm is attributed to the methylene protons from the octyl side chain. Additionally, peaks between 0.81 ppm and 1.16 ppm are associated with protons in the aliphatic side chains. In the case of Poly(PPO- alt- OF), peaks from 6.90 ppm and 8.39 ppm correspond to the protons of aromatic rings of phenoxazine, perylene, and fluorene moieties (Fig. 3 ). A distinct peak at 6.01 ppm is assigned to the “l” and “m” positions of the phenoxazine ring, while the peak at 1.96 ppm is the methylene protons from the octyl side chain. In addition, the peaks from 0.67 ppm to 1.53 ppm are attributed to the protons in octyl side chains. Overall, both Poly(BT- alt -OF) and Poly(PPO- alt- OF) exhibit all characteristic peaks in their 1 H NMR spectra. The analysis results from FT-IR, GPC, and 1 H NMR confirm that these polymers have been successfully synthesized via Suzuki polycondensation under aerobic conditions. 3.2 Optical and electrochemical properties Poly(BT- alt -OF) and Poly(PPO- alt -OF) conjugated polymers. Poly(BT- alt -OF) and Poly(PPO- alt- OF) demonstrated good solubility in a wide range of organic solvents, including tetrahydrofuran (THF), chloroform, chlorobenzene, and toluene. The absorption intensity and maximum absorption wavelength of Poly(BT- alt -OF) and Poly(PPO- alt- OF) were measured using UV-Vis spectroscopy in three different solvents – THF, CHCl 3 , and toluene (C M : ~ 10 µM) – as well as in solid-state thin films prepared by the spin coating method. In Fig. 4 a, it is observed that Poly(BT- alt -OF) exhibits two absorption peaks at λ = 319 nm and 446 nm in all organic solutions, and a slightly red shift to 466 nm in thin film form. Similarly, Poly(PPO- alt- OF) shows a maximum absorption at 417 nm in solvents and 422 nm in thin film (Fig. 4 b). Notably, both polymers do not exhibit a red shift in the solid-state thin film compared to solutions in non-polar solvents, indicating that intermolecular interactions of conjugated polymers is not significantly strengthened due to the presence of long alkyl side chains [ 34 , 35 ]. The optical bandgaps of Poly(BT- alt -OF) and Poly(PPO- alt- OF) were determined to be 2.25 eV and 2.06 eV, respectively, based on their λ onset . The photoluminescent spectra (PL) of Poly(BT- alt -OF) and Poly(PPO- alt- OF) were recorded in different solvents, including THF, CHCl 3 , and toluene, at a concentration of 1 µM. Emission wavelengths of the polymers were measured under excitation at 365 nm. Poly(BT- alt -OF) exhibited a peak at 534 nm (Fig. 5 a), while Poly(PPO- alt- OF) displayed a peak at 634 nm (Fig. 5 b). The fluorescence quantum yields (ФF) of both polymers in dilute CHCl 3 solutions were evaluated using the integrating sphere method, in comparison to 9,10-diphenylanthracene standard (ФF = 0.9). The ФF values of Poly(BT- alt -OF) and Poly(PPO- alt- OF) were determined to be 0.27 and 0.38, respectively, indicating that Poly(BT- alt -OF) has a stronger π–π stacking effect compared to Poly(PPO- alt- OF) [ 36 ]. In addition, thin films of studied polymers were prepared on ITO glasses (with a resistance of 5 Ω per square) by the spin-coating method at 1500 rpm using a special Teflon spin-coater from Laurell WS-400 to avoid the electrostatic effects on the surfaces of the films. The fluorescence properties of these thin films were investigated by exciting them at a wavelength of 365 nm using an integrated sphere spectrophotometer. Poly(BT- alt -OF) showed an emission peak at 539 nm. In comparison, Poly(PPO- alt- OF) displayed an emission peak at 600 nm (Fig. 6 ). These results indicate that the fluorescence emission of the synthesized polymers in the solid state closely resembles that of polymer solutions, suggesting that the π–π stacking characteristic of these polymers does not significantly affect their luminescence properties [ 37 – 39 ]. Next, reflectance spectroscopy was employed to examine the transmission characteristics of the studied polymers under visible light using the Ocean Optic USB400 spectrometer. Both Poly(BT- alt -OF) and Poly(PPO- alt- OF) exhibited transmission rates exceeding 80% from 525 nm to 850 nm (Fig. 7 ). In contrast, these polymers showed transmission rates from 30–70% at wavelengths below 500 nm. This finding suggests that the conjugated polymer layers are suitable for applications in transmittance displays for electronic devices [ 40 ]. To get deeper insights into the optical properties, the thin films of these conjugated polymers were investigated using CRAI microscopy spectroscopy instruments. Figure 8 illustrates the transmission spectroscopy of Poly(BT- alt -OF) at various points on a spin-coated film, ranging from the center to the edge. It is evident that the transmission at the center (red line) exceeds 90%, significantly higher than that of the outer positions (black line and blue line). This can be attributed to the fact that the thickness of the film at the center is considerably thinner than at the edges. Figure 9 presents the microscopy transmission spectroscopy of Poly(PPO- alt- OF), which displays a spectrum similar to that of Poly(BT- alt -OF). In the center area, the thin film demonstrates a transparency greater than 90%, whereas the transparency in the outer regions remains below 90%. These results indicate that the uniformity of thin films composed of the studied polymers significantly impacts their absorption and transmission properties. The electrochemical properties of the studied polymers were measured by cyclic voltammetry (CV) to elucidate their redox properties. The CV experiments of Poly(BT- alt -OF) and Poly(PPO- alt- OF) were conducted in acetonitrile, utilizing an Ag/Ag + as reference electrode, a platinum wire as counter electrode, and a conjugated polymer coated on a Pt disc as working electrode. All reported potentials were referenced to the Ag/Ag + electrode (0.1 M AgNO 3 / 0.1 M TBAPF 6 in CH 3 CN; 0.320 V vs. SCE), and the measurements were internally standardized with ferrocene (vs. Ag/Ag +). The scan rate was set at 50 mV s − 1 with V max = \(\:\pm\:\) 2V. The cyclic voltammogram of Poly(BT- alt -OF) exhibited a reduction peak at -0.69 V and an oxidation peak at + 1.49 V, which corresponded to a HOMO energy level of -5.89 eV (Fig. 10 a). For Poly(PPO- alt- OF), it possessed a reduction peak at -0.67 V and an oxidation peak at + 0.80 V, which attributed to a HOMO energy level of − 5.20 eV (Fig. 10 b). The LUMO energy levels of Poly(BT- alt -OF) and Poly(PPO- alt- OF) were determined based on the HOMO levels and their optical band gaps, to be -3.71 eV and − 3.73 eV, respectively. A comprehensive summary of the HOMO and LUMO levels, along with the estimated band gaps of studied polymers, is presented in Table 1 . Table 1 Electrochemical properties of Poly(BT- alt -OF) and Poly(PPO- alt- OF). Polymers E ox onset (V) a E g (eV) b HOMO (eV) c LUMO (eV) d Sheet Resistance (Ω/sq) e Poly(BT- alt -OF) 1.49 2.25 -5.89 -3.64 2.68 Poly(PPO- alt- OF) 0.8 2.06 − 5.20 -3.14 2.73 a Onset oxidation potential vs Ag/AgCl. b Estimated from the onset of absorption edge. c Estimated from the onset oxidation potential. d Deduced from HOMO and E g . e Room temperature (25 o C). The sheet resistance of the thin films was measured by a four-point probe method using a Mitsubishi Loresta-EP MCP-T360 apparatus. The sheet resistances of Poly(BT- alt -OF) and Poly(PPO- alt- OF) were recorded at approximately 12.83 Ω sq − 1 and 14.09 Ω sq − 1 at 25 o C. Further measurements demonstrated the variation of sheet resistance with temperature; specifically, the sheet resistance of Poly(BT- alt -OF) decreased from 12.83 Ω sq − 1 at 25 o C to 11.47 Ω sq − 1 at 0 o C, while Poly(PPO- alt- OF) exhibited a similar trend, declining from 13.01 Ω sq − 1 at 25 o C to 11.04 Ω sq − 1 at 0 o C (Fig. 11 ). This observed decrease in sheet resistance at lower temperatures can be attributed to aggregation phenomena that enhance the conductivity of conjugated polymers. However, as the temperature was reduced further to -5 o C, there was an increase in the sheet resistance of polymer thin films. This finding can be explained by the onset of moisture freezing on the surface, adversely affecting the conductivity of the polymer films. 3.3 Nitroaromatic explosives detection Next, we attempt to investigate the sensing capabilities of these two conjugated polymers, Poly(BT- alt -OF) and Poly(PPO- alt- OF), for the detection of nitroaromatic-based explosives, specifically 2,4,6-trinitrotoluene (TNT), Dinitrotoluene (DNT), Nitrobenzene (NB), 4-Nitrophenol (NP), and picric acid (PA). An optimization experiment was conducted to assess the fluorescence emission intensity of both polymers at a concentration of 1 µM in THF. The results showed that the PL intensity reached 830 a.u and 400 a.u for poly(BT- alt -OF) and poly(PPO- alt- OF), respectively, under excitation at 365 nm (Fig. 12 a and Fig. 13 a). To quantitatively evaluate the sensitivity of both polymers toward nitroaromatic explosive detection, solutions of nitroaromatics in THF were prepared at 10 − 1 M. Incremental additions of 20 µL of each nitroaromatic compound were made to the polymer solution within a quartz cuvette, followed by the recording of the emission spectra. As observed in Fig. 12 a and Fig. 13 a, the addition of nitroaromatic compounds led to a decrease in the PL intensity of the polymers. Among the investigated nitroaromatic compounds, picric acid exhibited the most pronounced fluorescence quenching efficiencies on both conjugated polymers. The fluorescence quenching efficiencies were measured at 15.6% for Poly(BT- alt -OF) and 37.5% for Poly(PPO- alt- OF) upon the addition of 20 µL of PA solution. The findings establish that picric acid possesses a significant capacity to quench the fluorescence of both polymers: Poly(BT- alt -OF) showed the quenching trend of PA > > 2,4-DNP ≈ 4-NP > TNT ≈ NB, while Poly(PPO- alt- OF) demonstrated PA >>> 2,4-DNP > TNT ≈ 4-NP ≈ NB. Therefore, picric acid was selected as the analyzer target for the fluorescence quenching mechanism. Figure 12 b illustrates that as the volume of PA increased from 0 to 200 µL, the PL intensity of Poly(BT- alt -OF) solution decreased to 18%, corresponding to the quenching fluorescence value of 82%. In contrast, the PL intensity of Poly(PPO- alt- OF) solution decreased to 10%, reflecting the quenching fluorescence of 92% (Fig. 13 b). Besides, the quenching constant, Ksv, was calculated using the Stern-Volmer formula: I o /I = 1 + K sv . C PA can be applied to estimate the efficiency of detection of PA, where I o and I are the fluorescence intensities before and after the presence of PA, C PA is the PA compound concentration, and K SV is the Stern-Volmer constant. As shown in Fig. 12 c, the K SV value of Poly(BT- alt -OF) was estimated to be 8.48 x 10 2 M − 1 , with the limit of detection (LOD) of 6.91 x 10 − 4 M. Meanwhile, Fig. 13 c indicated that the K SV value of Poly(PPO- alt- OF) was 3.08 x 10 3 M − 1 , with an LOD of 3.31 x 10 − 4 M. These findings demonstrate that both conjugated polymers exhibit high sensitivity to PA, surpassing the response of other nitroaromatic compounds. Moreover, the rapid and clearly visible fluorescence quenching responses of the conjugated polymers toward PA at low concentrations were distinctly observed under UV irradiation at 365 nm (see Fig. 12 d and Fig. 13 d). To archive the applicable process, the test papers are prepared for user in real-life situations. Filter papers (1 cm x 1 cm) were soaked in a polymer solution in THF (C M = 10 − 3 M) for 15 minutes, then dried and examined under a UV lamp (365 nm). The fluorescence emission properties of both conjugated polymers remained stable over 10 days, demonstrating that the polymer chains were effectively impregnated into the filter test papers. These impregnated papers were then used to detect nitro-explosives by sequentially dripping (5 µL) solutions containing NACs, including PA, 2,4-DNP, TNT, NP, and NB (C M = 10 − 3 M). As illustrated in Fig. 14 , Poly(BT- alt -OF) and Poly(PPO- alt- OF) are suitable for PA detection, showing a black spot of quenching at concentrations of 10 − 3 M and demonstrating sensitivity down to low concentrations of 10 − 4 M. This study confirmed that Poly(BT- alt -OF) and Poly(PPO- alt- OF) in solid-state can recognize PA with high sensitivity and selectivity. 4. Conclusion In this study, two fluorescent conjugated polymers, Poly(BT- alt -OF) and Poly(PPO- alt- OF) with average molecular weights of 5000 g mol − 1 , were designed and synthesized successfully using a modified Suzuki polymerization method under aerobic conditions. This approach opens up a simple new pathway for the synthesis of novel conjugated polymers where Suzuki reactions are applicable. The obtained conjugated polymers were thoroughly characterized in terms of their chemical structure, as well as their optical and thermal properties, both in solution and solid-state thin films. In addition, the polymers demonstrated high sensitivity to PA in fluorescence quenching with K SV constants of 8.48 x 10 2 M − 1 for Poly(BT- alt -OF) and 3.08 x 10 3 M − 1 for Poly(PPO- alt- OF), respectively. The detection limits for PA were determined to be approximately 6.91 x 10 − 4 M and 3.31 x 10 − 4 M, respectively. Furthermore, polymer-based filter papers were prepared and tested for practical applications, demonstrating effective detection of PA at low concentrations of 10 − 4 M. This study highlights promising materials and a potential method for selective, rapid, and trace determination of nitro-explosives using fluorescent polymers. Declarations Acknowledgements This research was supported by the Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number “104.02-2023.102”. The author thanks Key Laboratory for Polymer and Composite Materials, Viet Nam National University Ho Chi Minh City for their support to carry out this work. Funding The Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number “104.02-2023.102”. Contributions Luan Thanh Nguyen: Writing – original draft, Methodology, Investigation, Formal analysis. Thanh Tien Nguyen: Software, Methodology, Investigation, Formal analysis. Minh Duy Hoang: Software, Methodology, Investigation, Formal analysis. Tam Hoang Luu: Methodology, Investigation, Formal analysis. Le- Thu Thi Nguyen: Writing – review & editing, Validation, Software, Formal analysis. Hai Le Tran: Methodology, Investigation, Formal analysis. Tin Chanh Duc Doan : Software, Methodology, Investigation, Formal analysis. Chau Duc Tran : Writing – review & editing, Validation, Supervision, Resources, Project administration, Methodology, Funding acquisition. Tam Huu Nguyen: Writing – review, Methodology, Investigation, Formal analysis, Data curation, Conceptualization. Ha Tran Nguyen: Writing – review & editing, Writing – original draft, Validation, Supervision, Conceptualization. Ethics declarations Conflict of interest The authors declare no conflict of interest. Data availability Data will be made available on request. References Thomas SW, Joly GD, Swager TM (2007) Chemical Sensors Based on Amplifying Fluorescent Conjugated Polymers. Chem Rev 107:1339–1386. 10.1021/cr0501339 Sun X, Wang Y, Lei Y (2015) Fluorescence based explosive detection: from mechanisms to sensory materials. Chem Soc Rev 44:8019–8061. 10.1039/C5CS00496A Salinas Y, Martínez-Máñez R, Marcos MD, Sancenón F, Costero AM, Parra M et al (2012) Optical chemosensors and reagents to detect explosives. ChSRv 41:1261–1296. 10.1039/C1CS15173H Bilal M, Bagheri AR, Bhatt P, Chen S (2021) Environmental occurrence, toxicity concerns, and remediation of recalcitrant nitroaromatic compounds. J Environ Manage 291:112685. https://doi.org/10.1016/j.jenvman.2021.112685 Tiwari J, Tarale P, Sivanesan S, Bafana A (2019) Environmental persistence, hazard, and mitigation challenges of nitroaromatic compounds. Environ Sci Pollut Res 26:28650–28667. 10.1007/s11356-019-06043-8 Forbes TP, Sisco E (2018) Recent advances in ambient mass spectrometry of trace explosives. Analyst 143:1948–1969. 10.1039/C7AN02066J To KC, Ben-Jaber S, Parkin IP (2020) Recent Developments in the Field of Explosive Trace Detection. ACS Nano 14:10804–10833. 10.1021/acsnano.0c01579 Mohammed A-FA, Nabat KY, Jiang T, Liu L (2025) Recent innovations in explosive trace detection: Advances and emerging technologies. Trends Environ Anal Chem 46:e00261. https://doi.org/10.1016/j.teac.2025.e00261 Martelo LM, Marques LF, Burrows HD, Berberan-Santos MN (2019) Explosives Detection: From Sensing to Response. Springer International Publishing, Cham Caygill JS, Davis F, Higson SPJ (2012) Current trends in explosive detection techniques. Talanta 88:14–29. https://doi.org/10.1016/j.talanta.2011.11.043 De Iacovo A, Mitri F, De Santis S, Giansante C, Colace L (2024) Colloidal Quantum Dots for Explosive Detection: Trends and Perspectives. ACS Sens 9:555–576. 10.1021/acssensors.3c02097 Song JH, Kang DW (2023) Hazardous nitroaromatic explosives detection by emerging porous solid sensors. Coord Chem Rev 492:215279. https://doi.org/10.1016/j.ccr.2023.215279 Lustig WP, Mukherjee S, Rudd ND, Desai AV, Li J, Ghosh SK (2017) Metal–organic frameworks: functional luminescent and photonic materials for sensing applications. ChSRv 46:3242–3285. 10.1039/C6CS00930A He W, Duan J, Liu H, Qian C, Zhu M, Zhang W et al (2024) Conjugated microporous polymers for advanced chemical sensing applications. Prog Polym Sci 148:101770. https://doi.org/10.1016/j.progpolymsci.2023.101770 Xiaofu Wu HT, Lixiang W (2019) Fluorescent Polymer Materials for Detection of Explosives. Progress Chem 31:1509–1527. 10.7536/pc190734 Rochat S, Swager TM (2013) Conjugated Amplifying Polymers for Optical Sensing Applications. ACS Appl Mater Interfaces 5:4488–4502. 10.1021/am400939w Swager TM (1998) The Molecular Wire Approach to Sensory Signal Amplification. Acc Chem Res 31:201–207. 10.1021/ar9600502 Zen Eddin M, Zhilina EF, Chuvashov RD, Dubovik AI, Mekhaev AV, Chistyakov KA et al (2022) Random Copolymers of Styrene with Pendant Fluorophore Moieties: Synthesis and Applications as Fluorescence Sensors for Nitroaromatics. Molecules 27:6957 Liu W, Chen H, Zhang S, Li P, Wu W (2024) Synthesis of Novel Fluorescent Conjugated Polymers and Their Rapid Gas-Phase Detection of Trace Nitro-Explosives. Macromol Chem Phys 225:2300325. https://doi.org/10.1002/macp.202300325 Haque MH, Koh K, Sohn H (2023) Detection of TNT Vapors by Fluorescence Quenching and Self-Recovery Using Highly Fluorescent Conjugated Silole Polymers. Macromolecules 56:6396–6406. 10.1021/acs.macromol.2c02193 Lo CK, Wolfe RMW, Reynolds JR (2021) From Monomer to Conjugated Polymer: A Perspective on Best Practices for Synthesis. Chem Mater 33:4842–4852. 10.1021/acs.chemmater.1c01142 Ding L, Yu Z-D, Wang X-Y, Yao Z-F, Lu Y, Yang C-Y et al (2023) Polymer Semiconductors: Synthesis, Processing, and Applications. Chem Rev 123:7421–7497. 10.1021/acs.chemrev.2c00696 Phan S, Luscombe CK (2019) Recent Advances in the Green, Sustainable Synthesis of Semiconducting Polymers. Trends in Chemistry 1:670 – 81. 10.1016/j.trechm.2019.08.002 Huu Nguyen T, Le Tran H, Minh Phan H, Duy Hoang M, Nguyen L-TT, Chanh Duc Doan T et al (2024) Toward rapid and efficient protocols: Synthesis of benzotriazole-based π-conjugated polymers via direct arylation polycondensation under aerobic conditions. Eur Polym J 219:113369. https://doi.org/10.1016/j.eurpolymj.2024.113369 Carlucci C, Conelli D, Hassan Omar O, Margiotta N, Grisorio R, Suranna GP (2023) Toward eco-friendly protocols: insights into direct arylation polymerizations under aerobic conditions in anisole. Polym Chem 14:343–351. 10.1039/D2PY01214F Ichige A, Saito H, Kuwabara J, Yasuda T, Choi J-C, Kanbara T (2018) Facile Synthesis of Thienopyrroledione-Based π-Conjugated Polymers via Direct Arylation Polycondensation under Aerobic Conditions. Macromolecules 51:6782–6788. 10.1021/acs.macromol.8b01289 Sanzone A, Calascibetta A, Monti M, Mattiello S, Sassi M, Corsini F et al (2020) Synthesis of Conjugated Polymers by Sustainable Suzuki Polycondensation in Water and under Aerobic Conditions. ACS Macro Lett 9:1167–1171. 10.1021/acsmacrolett.0c00495 Bezgin Carbas B (2022) Fluorene based electrochromic conjugated polymers: A review. Poly 254:125040. https://doi.org/10.1016/j.polymer.2022.125040 Al-Sharji H, Ilmi R, Khan MS (2024) Recent Progress in Phenoxazine-Based Thermally Activated Delayed Fluorescent Compounds and Their Full-Color Organic Light-Emitting Diodes. Top Curr Chem 382:5. 10.1007/s41061-024-00450-3 Borissov A, Maurya YK, Moshniaha L, Wong W-S, Żyła-Karwowska M, Stępień M (2022) Recent Advances in Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds. Chem Rev 122:565–788. 10.1021/acs.chemrev.1c00449 Cong P, Wang Z, Geng Y, Meng Y, Meng C, Chen L et al (2023) Benzothiadiazole-based polymer donors. Nano Energy 105:108017. https://doi.org/10.1016/j.nanoen.2022.108017 Nguyen CHT, Nguyen TH, Nguyen TPL, Le Tran H, Luu TH, Tran CD et al (2023) Aerobic direct arylation polycondensation of N-perylenyl phenoxazine-based fluorescent conjugated polymers for highly sensitive and selective TNT explosives detection. Dyes Pigm 219:111613. https://doi.org/10.1016/j.dyepig.2023.111613 Dos Santos JM, Hall D, Basumatary B, Bryden M, Chen D, Choudhary P et al (2024) The Golden Age of Thermally Activated Delayed Fluorescence Materials: Design and Exploitation. Chem Rev 124:13736–14110. 10.1021/acs.chemrev.3c00755 Mei J, Bao Z (2014) Side Chain Engineering in Solution-Processable Conjugated Polymers. Chem Mater 26:604–615. 10.1021/cm4020805 Luo N, Ren P, Feng Y, Shao X, Zhang H-L, Liu Z (2022) Side-Chain Engineering of Conjugated Polymers for High-Performance Organic Field-Effect Transistors. J Phys Chem Lett 13:1131–1146. 10.1021/acs.jpclett.1c03909 Welscher PJ, Ziener U, Kuehne AJC (2025) Fluorene Oligomers Featuring a Central 2,1,3-Benzothiadiazole Unit with High Photoluminescence Quantum Yield and Amplified Spontaneous Emission. Macromolecules 58:2730–2735. 10.1021/acs.macromol.4c03110 Ye S, Bao Y (2024) Recent Advances in Fluorescent Polymers with Color-Tunable Aggregate Emission. Chem Mater 36:5878–5896. 10.1021/acs.chemmater.3c02714 Belmonte-Vázquez JL, Amador-Sánchez YA, Rodríguez-Cortés LA, Rodríguez-Molina B (2021) Dual-State Emission (DSE) in Organic Fluorophores: Design and Applications. Chem Mater 33:7160–7184. 10.1021/acs.chemmater.1c02460 Gon M, Tanaka K, Chujo Y (2023) π-Conjugated polymers based on flexible heteroatom-containing complexes for precise control of optical functions. Polym J 55:723–734. 10.1038/s41428-023-00779-4 Nair NM, Zumeit A, Dahiya R (2025) Transparent and Transient Flexible Electronics. Adv Sci 12:e05133. https://doi.org/10.1002/advs.202505133 Schemes Scheme 1 is available in the Supplementary Files section Supplementary Files Graphicalabstract25082025.docx image1.png Scheme 1. Synthesis route of Poly(BT- alt -OF) (P1) and Poly(PPO- alt- OF) (P2). Cite Share Download PDF Status: Published Journal Publication published 10 Nov, 2025 Read the published version in Journal of Polymer Research → Version 1 posted Reviewers agreed at journal 02 Oct, 2025 Reviewers invited by journal 02 Oct, 2025 Editor invited by journal 12 Sep, 2025 Editor assigned by journal 27 Aug, 2025 First submitted to journal 26 Aug, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7460772","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":523633816,"identity":"3b442673-054b-48c0-b8e0-32750d505276","order_by":0,"name":"Luan Thanh Nguyen","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Luan","middleName":"Thanh","lastName":"Nguyen","suffix":""},{"id":523633817,"identity":"260b8cc1-59bc-43ce-a477-7eb06bbb64bf","order_by":1,"name":"Thanh Tien Nguyen","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Thanh","middleName":"Tien","lastName":"Nguyen","suffix":""},{"id":523633818,"identity":"4cd10d18-9b8e-42ad-aed0-fde28376e66b","order_by":2,"name":"Minh Duy Hoang","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Minh","middleName":"Duy","lastName":"Hoang","suffix":""},{"id":523633819,"identity":"94910393-b72a-4f93-8631-3ff38b7e9b5f","order_by":3,"name":"Tam Hoang Luu","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Tam","middleName":"Hoang","lastName":"Luu","suffix":""},{"id":523633820,"identity":"ae9ea0d4-2303-4d9f-a777-687921c4d309","order_by":4,"name":"Le-Thu Thi Nguyen","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Le-Thu","middleName":"Thi","lastName":"Nguyen","suffix":""},{"id":523633821,"identity":"95a3a6c8-4194-4d5a-8a50-0c92ddd8b58c","order_by":5,"name":"Hai Le Tran","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Hai","middleName":"Le","lastName":"Tran","suffix":""},{"id":523633822,"identity":"d511ab28-dc63-4d07-8376-3f6ec85fbbcd","order_by":6,"name":"Tin Chanh Duc Doan","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Tin","middleName":"Chanh Duc","lastName":"Doan","suffix":""},{"id":523633823,"identity":"5cf3a040-3c00-43b5-b253-4c116517d549","order_by":7,"name":"Chau Duc Tran","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Chau","middleName":"Duc","lastName":"Tran","suffix":""},{"id":523633824,"identity":"254bdda5-24ab-4b19-8d46-0ec0f322fbe1","order_by":8,"name":"Tam Huu Nguyen","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Tam","middleName":"Huu","lastName":"Nguyen","suffix":""},{"id":523633825,"identity":"2adbb8b3-3cd7-461b-b961-0a2634e22303","order_by":9,"name":"Ha Tran Nguyen","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+klEQVRIiWNgGAWjYHADHgaGjw0INiFgAFbGOBOkhY0ULcy8xGgx519jJvFxx598/tm9Bz/b7rCLNrjfwPjgbRtD4nYcWixnvDGTnHnGwHLGnXPJ0rlnknM3HGNgNpwL1LKzAbsWgxtnzKR52wwMGG7kGEjnth0AaWEDijAYGxzAo+UvUIv8jRzj35YQLey/8Wo532MmzQjUYnAjB8SA2MIM1CKH2xa2YsveNmMDQ6AWICM5d+axxGbJOeckcGs5f3jjjZ9tcgZyQIcBGXa5fYcPH/zwpsyGB5cWBokEFgk0IcYGkDgO9UDAf4D5A27ZUTAKRsEoGAVAAABNTV2lNGlk7AAAAABJRU5ErkJggg==","orcid":"","institution":"Ho Chi Minh City University of Technology","correspondingAuthor":true,"prefix":"","firstName":"Ha","middleName":"Tran","lastName":"Nguyen","suffix":""}],"badges":[],"createdAt":"2025-08-26 08:50:44","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7460772/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7460772/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10965-025-04664-x","type":"published","date":"2025-11-10T15:58:37+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":93576048,"identity":"3373c33e-bb9e-4761-be9d-66cc799d72b7","added_by":"auto","created_at":"2025-10-15 09:27:05","extension":"xml","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":9385,"visible":true,"origin":"","legend":"","description":"","filename":"jpolJPOLD2501366.xml","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/eeeca8dc9ae58763204a2441.xml"},{"id":93576051,"identity":"90305fbb-e3f6-4206-8077-97c17ae7f648","added_by":"auto","created_at":"2025-10-15 09:27:05","extension":"xml","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1004,"visible":true,"origin":"","legend":"","description":"","filename":"JPOLD250136631320.go.xml","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/7d8b92bc2364d66ea2d518fa.xml"},{"id":93576481,"identity":"aef79ad1-ee8a-44ee-8842-c1987b9efa72","added_by":"auto","created_at":"2025-10-15 09:35:05","extension":"xml","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":903,"visible":true,"origin":"","legend":"","description":"","filename":"JPOLD2501366Import.xml","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/c600e944912cadef6b09657e.xml"},{"id":93577940,"identity":"c15e8d19-09c6-4f1f-a6b6-3cb5c2004b31","added_by":"auto","created_at":"2025-10-15 09:51:05","extension":"xml","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":128071,"visible":true,"origin":"","legend":"","description":"","filename":"JPOLD25013660enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/02019cc31bc3149318285ca8.xml"},{"id":93576482,"identity":"eef1ddd2-4eb1-4a6e-b82c-827458643edb","added_by":"auto","created_at":"2025-10-15 09:35:05","extension":"png","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":132243,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/8c57172becee7300a96f8fb1.png"},{"id":93576491,"identity":"2f904671-c829-4ea5-9c48-881f8b976094","added_by":"auto","created_at":"2025-10-15 09:35:06","extension":"png","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":367406,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage10.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/321b21728b2f8dd450b3cd84.png"},{"id":93576063,"identity":"741474b1-86ae-4652-81b9-986081bbf5a9","added_by":"auto","created_at":"2025-10-15 09:27:05","extension":"png","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":142868,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage11.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/fa2180caaa1e02a4abb73eee.png"},{"id":93576062,"identity":"46fde80c-84a2-4771-a5bb-411843bc8429","added_by":"auto","created_at":"2025-10-15 09:27:05","extension":"png","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":63790,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage12.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/f388bddc32e4f21701682abd.png"},{"id":93576072,"identity":"9e4aa037-3ccc-44ce-99e1-e3cfd9ed2793","added_by":"auto","created_at":"2025-10-15 09:27:05","extension":"png","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":370159,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage13.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/045d8a006f8462305c7bf19b.png"},{"id":93576486,"identity":"9cd0ab4c-3097-409e-9950-f3bfb8062bda","added_by":"auto","created_at":"2025-10-15 09:35:05","extension":"png","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":329428,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage14.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/c64e22a00fa2c4e935b4f0ef.png"},{"id":93576066,"identity":"65267572-e1d6-4d20-9552-971e25f7f205","added_by":"auto","created_at":"2025-10-15 09:27:05","extension":"png","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":814285,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage15.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/b954a342550c94896eeeaa83.png"},{"id":93576490,"identity":"bfcdcf04-488e-409a-9625-52ddc8ff17a9","added_by":"auto","created_at":"2025-10-15 09:35:06","extension":"png","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":240316,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/e95b83e5d4195e24a4fc5035.png"},{"id":93576499,"identity":"264dce83-3c98-4e44-80ec-39e1e4f9af79","added_by":"auto","created_at":"2025-10-15 09:35:06","extension":"png","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":175057,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/36292d4239a4b2333bd0878a.png"},{"id":93576067,"identity":"c76ebc9a-02da-4822-892c-1c056fb7b02a","added_by":"auto","created_at":"2025-10-15 09:27:05","extension":"png","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":119250,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/56772f0e3215bdea1ba07a4a.png"},{"id":93576071,"identity":"b8fc5130-197a-4e9f-9e33-f033b6a0ce45","added_by":"auto","created_at":"2025-10-15 09:27:05","extension":"png","order_by":16,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":237355,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/bdd745bbd14022a649b74556.png"},{"id":93576502,"identity":"aa7183ca-480c-4821-a5c1-14aaac9a1399","added_by":"auto","created_at":"2025-10-15 09:35:06","extension":"png","order_by":17,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":402117,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/51b27f9bb8dac8747b51f3bb.png"},{"id":93576086,"identity":"f836631b-c760-42a9-bd80-1b80e52bf8a8","added_by":"auto","created_at":"2025-10-15 09:27:06","extension":"png","order_by":18,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":81626,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/37919ca431584998cc3479fe.png"},{"id":93576493,"identity":"abff4b32-8a16-42ef-bcd4-84bb557f0f41","added_by":"auto","created_at":"2025-10-15 09:35:06","extension":"png","order_by":19,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":67132,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/58e6a5ab405582ed8e325a9d.png"},{"id":93576495,"identity":"2f625072-7cb4-409c-ad3b-3582d2128820","added_by":"auto","created_at":"2025-10-15 09:35:06","extension":"png","order_by":20,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":285810,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage9.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/16d42ad05f0c0150ead4158b.png"},{"id":93576498,"identity":"abb20685-2d6a-4cce-8e3b-ada3c19d4b08","added_by":"auto","created_at":"2025-10-15 09:35:06","extension":"png","order_by":21,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":43624,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/a2139027da11f1fe8f4515a3.png"},{"id":93576494,"identity":"828cdf81-6bc6-4071-ba71-ab028474dbf4","added_by":"auto","created_at":"2025-10-15 09:35:06","extension":"png","order_by":22,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":26802,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage10.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/e1d9d7dd6df31931842782be.png"},{"id":93576083,"identity":"d0f56543-fda3-4401-8298-fe52124bda15","added_by":"auto","created_at":"2025-10-15 09:27:06","extension":"png","order_by":23,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":36518,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage11.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/838e89f31b8369d47ac15143.png"},{"id":93576093,"identity":"6b22359b-2c69-4695-ab44-52458a097905","added_by":"auto","created_at":"2025-10-15 09:27:06","extension":"png","order_by":24,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":8705,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage12.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/5a826f80e0744ec5a0dc6a0e.png"},{"id":93576076,"identity":"ab2be66c-2275-4257-a5b9-e4f5db38b043","added_by":"auto","created_at":"2025-10-15 09:27:06","extension":"png","order_by":25,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":39713,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage13.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/4933a00b64ac42d6d6ce3e7b.png"},{"id":93576085,"identity":"fee718fb-f7c7-4223-b768-c3539b0a9e1f","added_by":"auto","created_at":"2025-10-15 09:27:06","extension":"png","order_by":26,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":38176,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage14.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/b7923c3ed93e74df0dfd1ce6.png"},{"id":93576092,"identity":"a49a22ce-71f4-4248-bdc6-1402ebe7f139","added_by":"auto","created_at":"2025-10-15 09:27:06","extension":"png","order_by":27,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":39571,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage15.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/7e5095a4899eeed879ca9c47.png"},{"id":93576096,"identity":"0174a8a9-0d08-438d-9cdb-ba6ff45d6607","added_by":"auto","created_at":"2025-10-15 09:27:06","extension":"png","order_by":28,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":55926,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/1fc81253b6163c5940a81627.png"},{"id":93576077,"identity":"1ef1f9a9-4990-4af0-a1f7-6029371b2979","added_by":"auto","created_at":"2025-10-15 09:27:06","extension":"png","order_by":29,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":27008,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/9c06a37978443d69d4febf0b.png"},{"id":93576497,"identity":"93266d87-ecd7-4494-b331-6ddec01c82ed","added_by":"auto","created_at":"2025-10-15 09:35:06","extension":"png","order_by":30,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":36760,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/1c35914e29ab41589a2305bd.png"},{"id":93577743,"identity":"c9592a0d-1326-4e31-900a-87152c4dff6b","added_by":"auto","created_at":"2025-10-15 09:43:06","extension":"png","order_by":31,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":55364,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/b0106d43b410761ab3e4b280.png"},{"id":93576097,"identity":"3ebf036b-5ebf-403c-8b08-8d321e8bf9bc","added_by":"auto","created_at":"2025-10-15 09:27:07","extension":"png","order_by":32,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":56543,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/2873a24dea7b2cd84f2663ec.png"},{"id":93576081,"identity":"7102639d-7bb8-4a1b-a8e5-f56ac53f0d7c","added_by":"auto","created_at":"2025-10-15 09:27:06","extension":"png","order_by":33,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":14894,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/e36e73d4bf66c8ca9d650339.png"},{"id":93576492,"identity":"0d416d70-5027-4ed8-8629-02119daf3883","added_by":"auto","created_at":"2025-10-15 09:35:06","extension":"png","order_by":34,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":13465,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/facd853e8e9659e787c7d1ee.png"},{"id":93576075,"identity":"ccc04957-4f19-4462-aec0-fceb9c0321e5","added_by":"auto","created_at":"2025-10-15 09:27:06","extension":"png","order_by":35,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":32841,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage9.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/20166015a6c8abef983ad288.png"},{"id":93576500,"identity":"05fc60dd-e8a1-41f9-acac-e4c1b39b8a69","added_by":"auto","created_at":"2025-10-15 09:35:06","extension":"xml","order_by":36,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":126776,"visible":true,"origin":"","legend":"","description":"","filename":"JPOLD25013660structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/70d329796ce518449b00abe3.xml"},{"id":93576094,"identity":"eaa379ec-7f22-40e8-b921-3e2dda64e319","added_by":"auto","created_at":"2025-10-15 09:27:06","extension":"html","order_by":37,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":139196,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/4daf4d334be1b98416fe07c0.html"},{"id":93576047,"identity":"fe277388-4505-4768-b630-27fc79658b26","added_by":"auto","created_at":"2025-10-15 09:27:05","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":373107,"visible":true,"origin":"","legend":"\u003cp\u003eFTIR spectrum (a) and GPC curves of the Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) (b).\u003c/p\u003e","description":"","filename":"image2.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/aa29c387622fec406a242587.png"},{"id":93576046,"identity":"6ab573fd-1878-4c14-8a0b-41955d17012b","added_by":"auto","created_at":"2025-10-15 09:27:05","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":275263,"visible":true,"origin":"","legend":"\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eH NMR spectrum of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) in CDCl\u003csub\u003e3\u003c/sub\u003e.\u003c/p\u003e","description":"","filename":"image3.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/d8778b11f2f379aef5b4fc35.png"},{"id":93576050,"identity":"e2694afd-b852-402b-8188-3b41c5a98865","added_by":"auto","created_at":"2025-10-15 09:27:05","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":433493,"visible":true,"origin":"","legend":"\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eH NMR spectrum of Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) in CDCl\u003csub\u003e3\u003c/sub\u003e.\u003c/p\u003e","description":"","filename":"image4.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/00c570cdb238ec968a99f602.png"},{"id":93576478,"identity":"3bde0a62-5fad-4c97-83f3-5cf2a181ef29","added_by":"auto","created_at":"2025-10-15 09:35:05","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":340445,"visible":true,"origin":"","legend":"\u003cp\u003eUV–Vis spectra of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) (a) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) (b) in solution and thin film.\u003c/p\u003e","description":"","filename":"image5.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/4eb7e8d0c5c6d516dbf3e73e.png"},{"id":93577741,"identity":"966e795e-0d61-4545-84e7-de7fea14ba1f","added_by":"auto","created_at":"2025-10-15 09:43:05","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":300542,"visible":true,"origin":"","legend":"\u003cp\u003ePL spectra of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) (a) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) (b) in different solvents.\u003c/p\u003e","description":"","filename":"image6.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/3cd6f04e9b27361589f54c3f.png"},{"id":93576055,"identity":"eb1f290e-f589-4112-9734-b3b159f09d88","added_by":"auto","created_at":"2025-10-15 09:27:05","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":228650,"visible":true,"origin":"","legend":"\u003cp\u003ePL spectra of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) in spin-coated thin films.\u003c/p\u003e","description":"","filename":"image7.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/8da46235772e7dc488826dd3.png"},{"id":93576487,"identity":"daeba3a0-5acc-4c5d-b7d1-344bcbadde24","added_by":"auto","created_at":"2025-10-15 09:35:05","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":204351,"visible":true,"origin":"","legend":"\u003cp\u003eTransmission spectra of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) in films under visible light.\u003c/p\u003e","description":"","filename":"image8.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/eb7290397b643c91d4098b5f.png"},{"id":93576479,"identity":"93920df8-6a1a-48d7-b096-0040a344c581","added_by":"auto","created_at":"2025-10-15 09:35:05","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":260253,"visible":true,"origin":"","legend":"\u003cp\u003eTransmission optical-microscopy spectrometer of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF).\u003c/p\u003e","description":"","filename":"image9.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/55868e87fae59b5a9b3118b6.png"},{"id":93576485,"identity":"c192ad0e-f923-4356-bfc4-5f07a5df73c8","added_by":"auto","created_at":"2025-10-15 09:35:05","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":224827,"visible":true,"origin":"","legend":"\u003cp\u003eTransmission optical-microscopy spectrometer of Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF).\u003c/p\u003e","description":"","filename":"image10.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/41a068890c28f5b0b9e287a5.png"},{"id":93576489,"identity":"8c6bd900-d4b3-4d1b-9b03-cadef0687378","added_by":"auto","created_at":"2025-10-15 09:35:05","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":266754,"visible":true,"origin":"","legend":"\u003cp\u003eCyclic Voltammograms of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) (a) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) (b).\u003c/p\u003e","description":"","filename":"image11.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/bc5f87dd2348a8ae13e72156.png"},{"id":93576488,"identity":"f6fcbde6-d271-47c7-88c8-75990b808d6f","added_by":"auto","created_at":"2025-10-15 09:35:05","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":162867,"visible":true,"origin":"","legend":"\u003cp\u003eThe sheet resistance values of studied polymers at different temperature.\u003c/p\u003e","description":"","filename":"image12.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/540dc49be1e83100ae172a91.png"},{"id":93576060,"identity":"4156ef6e-dda1-4ee2-9017-b556368d46e4","added_by":"auto","created_at":"2025-10-15 09:27:05","extension":"png","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":403353,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Response in fluorescence emission spectra of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) (0.1 μM in THF) with nitroaromatic compounds. (b) Response in fluorescence emission spectra of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) with picric acid (PA) at different concentrations. (c) Stern-Volmer plot for quenching of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) by picric acid. (d) The visual detection experiment for Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) in THF under UV irradiation at 365 nm in the presence of picric acid.\u003c/p\u003e","description":"","filename":"image13.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/f462e2d3bbe5363ce02f261d.png"},{"id":93576074,"identity":"82acc928-48c8-4412-8c29-f4b11be13d84","added_by":"auto","created_at":"2025-10-15 09:27:06","extension":"png","order_by":13,"title":"Figure 13","display":"","copyAsset":false,"role":"figure","size":397666,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Response in fluorescence emission spectra of Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) (0.1 μM in THF) with nitroaromatic compounds. (b) Response in fluorescence emission spectra of Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) with picric acid (PA) at different concentrations. (c) Stern-Volmer plot for quenching of poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) by picric acid. (d) The visual detection experiment for Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) in THF under UV irradiation at 365 nm in the presence of picric acid.\u003c/p\u003e","description":"","filename":"image14.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/83a10cbe94fcd6ba33dfb6b5.png"},{"id":93576065,"identity":"7e72c430-04ab-4941-bbbd-d4698c966d25","added_by":"auto","created_at":"2025-10-15 09:27:05","extension":"png","order_by":14,"title":"Figure 14","display":"","copyAsset":false,"role":"figure","size":220672,"visible":true,"origin":"","legend":"\u003cp\u003ePaper test of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) (a) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) (b) with different nitroaromatics under UV light (365 nm).\u003c/p\u003e","description":"","filename":"image15.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/243219096f1f31676cfd4092.png"},{"id":96105789,"identity":"9f2b5358-4013-4d0b-b65d-6714c42c3f0c","added_by":"auto","created_at":"2025-11-17 16:11:42","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":5076017,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/047b45be-62a0-42c5-aa1f-024124702db5.pdf"},{"id":93577740,"identity":"3d37421c-6a66-4d24-ad20-df99d79136ff","added_by":"auto","created_at":"2025-10-15 09:43:05","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":441504,"visible":true,"origin":"","legend":"","description":"","filename":"Graphicalabstract25082025.docx","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/768935c4f98b66c8991e8135.docx"},{"id":93576052,"identity":"f2e53a43-0d9c-461e-ae5d-ea934ba74d58","added_by":"auto","created_at":"2025-10-15 09:27:05","extension":"png","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":425486,"visible":true,"origin":"","legend":"\u003cp\u003eScheme 1. Synthesis route of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) (P1) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) (P2).\u003c/p\u003e","description":"","filename":"image1.png","url":"https://assets-eu.researchsquare.com/files/rs-7460772/v1/12953a8357f5815b93b3d786.png"}],"financialInterests":"","formattedTitle":"N-perylenyl phenoxazine and fluorene-based conjugated copolymer as a potential fluorescent probe for nitroaromatic explosives detection","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eThe nitroaromatic compounds (NACs) are recognized for their toxicity and explosive characteristics, posing significant risks to both human health and aquatic ecosystems [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Among explosive compounds, the 2,4,6-trinitrotoluene (TNT), Picric acid (PA, as known 2,4,6-trinitrophenol), 2,4-dinitrotoluene (DNT), and 2,4-dinitrophenol (DNP) are particularly notable due to their strong explosive characteristics, commonly utilized in industries such as mining, fireworks, and gunpowder manufacturing [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Therefore, significant amounts of these explosive compounds have been released into the environment, leading to serious health consequences for humans, including symptoms such as vomiting, lung cancer, convulsions, and so on [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. To date, various methods have been developed to detect the explosive compounds in soil, water sources, and industrial waste, including high-performance liquid chromatography, spectroscopy, and electrochemistry [\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. While these techniques can identify the explosive compounds in nano/micro-scale amounts, they require state-of-the-art instruments that necessitate maintenance and involve complex operation systems.\u003c/p\u003e\u003cp\u003eRecent advancements in the field of chemsensing have focused on the utilization of sensitive fluorescent materials as chemosensors for the detection of explosive compounds [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. These materials enhance optical signals through various fluorescence mechanisms, including photo-induced electron transfer (PET), fluorescence resonance energy transfer (FRET), electron exchange, and intermolecular charge transfer (ICT) [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. However, achieving high sensitivity and selectivity remains a significant challenge, particularly for the detection of the analytes at very low concentrations. To address this challenge, a range of fluorescent materials has been developed, including quantum dots (QDs) [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], metal-organic frameworks (MOFs) [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], porous organic polymers (POPs) [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], small molecules and fluorescent polymers [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Among these, conjugated polymers have garnered extensive research interest due to their straightforward synthetic procedures, good chemical stability, and robust optical emission properties [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. In addition, the structural design of conjugated fluorescent polymers can be tailored to enhance their electron donor capacity via delocalized π* excited states, thereby facilitating a molecular wire effect that amplifies interactions with explosive analytes [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. For instance, Eddin \u003cem\u003eet. al\u003c/em\u003e synthesized five random copolymers based on styrene, incorporating various fluorophore pendant groups such as pyrene, naphthalene, phenanthrene, and triphenylamine as semi-conjugated polymers for the detection of nitroaromatic compounds [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. These copolymers exhibited absolute quantum yields as high as 0.93 in the solid state, depending on their fluorophore composition, with the detection limits ranging from 10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e to 10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e mol L\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for nitroaromatics in dichloromethane solution. More recently, Liu \u003cem\u003eet. al\u003c/em\u003e reported the synthesis of fluorescent conjugated polymers derived from 1,6-dibromopyrene and 9,9-dioctyl-2,7-dibromofluorene. Their approach employs linkages involving both \u0026ldquo;single bond\u0026rdquo; and \u0026ldquo;alkyne bond\u0026rdquo; chemistry, resulting in the limit of detections (LOD) of these conjugated polymers for liquid-phase TNT below 2.0 \u0026micro;M [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. In 2023, Haque introduced two rigid types of conjugated poly(dioctaloxybenzenesilole) that incorporated octyloxybenzene subunits, namely, 1,1-dibutyl-3,4-diphenylbis(2,5-bis(octaloxy)benzene)-2,5-polysilole and 1,1-dibutyl-3,4-diphenyltris(2,5-bis(octaloxy)benzene)-2,5-polysilole, synthesized through an intricate series of steps. The resulting materials exhibited the quenching of fluorescence at a concentration of 217 \u0026micro;M TNT in the liquid state [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe structural design of fluorescent conjugated polymers is pivotal in leveraging their sensing performance for tracing of explosive compounds, yet the synthesis procedure of such polymers poses a great challenge [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Achieving high purity, homogeneous structures, low polydispersity index, and satisfactory yields is essential. Traditional synthetic methodologies, including Suzuki, Heck, Stille, and Sonogashira coupling reactions, often require complicated multiple steps involving anhydrous solvents, living catalysts, and cryogenic conditions [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Therefore, a simplified synthesis procedure employing an efficient catalyst with high-yield reactions is necessary for producing fluorescent conjugated polymers [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. To address this issue, aerobic polymerization emerges as the most effective method for synthesizing conjugated polymers [\u003cspan additionalcitationids=\"CR25 CR26\" citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. Regarding constructive building blocks, dialkylfluorene and phenoxazine derivatives are well known as fluorescent components utilized in electrochromic and organic light-emitting diode devices [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. In addition, the perylene unit features a large π-conjugated system that exhibits strong fluorescence, a long fluorescence lifetime, and chemical stability [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. Moreover, the benzo[c][\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]thiadiazoles are widely used in conjugated polymers, serving as favorable binding groups [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. They help reduce steric hindrance and enhance the localization of electrons along the main chain of conjugated polymers.\u003c/p\u003e\u003cp\u003eIn this study, we synthesize new fluorescent conjugated polymers containing 10-(perylen-3-yl)-10H-phenoxazine, benzo[c][\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]thiadiazole, and 9,9-dioctyl-9H-fluorene moieties within the main chain, along with perylene fluorophores in the side chain. This design aims to enhance the interaction between the CPs explosive compounds such as PA, TNT and DNT. Building upon this foundation, we perform model Suzuki polycondensation under aerobic conditions to prepare conjugated polymers featuring 9,9-dioctyl-9H-fluorene with either 10-(perylen-3-yl)-10H-phenoxazine or benzo[c][\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]thiadiazole. The synthesized polymers are characterized using Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (\u003csup\u003e1\u003c/sup\u003eH NMR), and gel permeation chromatography (GPC) to determine their chemical structures. We further investigate their optical and electrical properties through ultraviolet-visible (UV-Vis) spectroscopy, fluorescence (FL) spectroscopy, reflective spectroscopy, cyclic voltammetry, and four-point measurements. Additionally, the thermal properties of polymers are characterized by differential scanning calorimetry (DSC). In order to acknowledge their practical applications, the synthesized conjugated polymers have been applied as fluorescent sensors for the detection of nitroaromatic explosives across various phases, including both solution and solid states.\u003c/p\u003e"},{"header":"2. Experimental","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003e2.1 Materials and chemicals\u003c/h2\u003e\u003cp\u003e4,7-dibromobenzo[c][\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]thiadiazole (95%), 2,2'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) (95%), Palladium(II) acetate (98%), Tris(o-methoxyphenyl)phosphine (96%), phenooxazine (97%), sodium borohydride (NaBH\u003csub\u003e4\u003c/sub\u003e, 99%), triethylamine (99%), Potassium phosphate (K\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e) (99%) and 3-Bromoperylene (95%), were purchased from Sigma Aldrich and used as received. Tetrahydrofuran (THF) (99.5%) was purchased from Fisher and dried using molecular sieves under N\u003csub\u003e2\u003c/sub\u003e. Chloroform (CHCl\u003csub\u003e3\u003c/sub\u003e), Toluene (99%), Dichloromethane (CH\u003csub\u003e2\u003c/sub\u003eCl\u003csub\u003e2\u003c/sub\u003e) (99.8%), n-heptane (99%), methanol (99%), ethyl acetate (99%), and diethyl ether (99%) were purchased from Fisher/Acros (Bridgewater, NJ, USA) and used as received. Silica gel 60 (0.063\u0026ndash;0.200 mm) for column chromatography was purchased from Merck and used as received.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003e2.2 Characterization\u003c/h2\u003e\u003cp\u003eGPC measurements were carried out using a Varian Polymer PL-GPC 50 gel permeation chromatography system equipped with an RI detector and a mesopore column, employing chloroform as the eluent with a flow rate of 1.0 ml min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e at 30 \u003csup\u003eo\u003c/sup\u003eC. The pressure over the column was 5.7 MPa. The average molecular weight and molecular weight distribution of the obtained polymers were determined using polystyrene (PS) standards. \u003csup\u003e1\u003c/sup\u003eH NMR spectra were characterized on a Bruker Avance 500 MHz using deuterated chloroform (CDCl\u003csub\u003e3\u003c/sub\u003e) as a solvent and tetramethylsilane as an internal reference. FT-IR spectroscopy was performed using Thermo Nicolet 6700 spectrometer, with 264 scans recorded from 400 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 4000 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. UV-Vis spectroscopy of the conjugated polymers was recorded on an Agilent UV\u0026ndash;Vis 8453 diode array spectrometer over the wavelength range of 200 nm to 1100 nm, supported by a Peltier controller. Fluorescence spectra were measured using a Varian Cary Eclipse Fluorescence Spectrometer. Fluorescence spectra of solid-state thin films were acquired using an Ocean Optics USB4000 spectrophotometer with an integrated sphere, excited by a 365 nm LED-UV wavelength. Transmission spectroscopy was performed on Ocean Optics Maya 2000 Pro spectrophotometer with an integrated sphere under visible light ranging from 400 nm to 900 nm. Microscopy spectroscopy was recorded on CRAI spectroscopy using OCEAN OPTIC SF2000 instrument with a Lumenera infinity 1 microscopy camera. Differential scanning calorimetry (DSC) analysis was performed using TA instrument 2910 under nitrogen flow with a heating rate of 10\u0026deg;C min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e from \u0026minus;\u0026thinsp;20 \u003csup\u003eo\u003c/sup\u003eC to 300\u0026deg;C. Electrochemical measurements were investigated on an AUTOLAB instrument using NOVA 1.11 software. The electrochemical experiments used an Au disc working electrode and a Pt wire counter electrode. The electrochemical solution consisted of 0.1 M TBAPF\u003csub\u003e6\u003c/sub\u003e in CH\u003csub\u003e3\u003c/sub\u003eCN, which was purged with argon for 20 minutes prior to data collection. All potentials are referenced to a Ag/Ag\u003csup\u003e+\u003c/sup\u003e reference electrode (0.1 M AgNO\u003csub\u003e3\u003c/sub\u003e/0.1 M TBAPF\u003csub\u003e6\u003c/sub\u003e in CH\u003csub\u003e3\u003c/sub\u003eCN; 0.320 V vs. SCE) and internally standardized with ferrocene (vs. Ag/Ag\u003csup\u003e+\u003c/sup\u003e). E\u003csub\u003eHOMO\u003c/sub\u003e values were determined in reference to ferrocene. The polymer film was coated onto an electrode that had been washed with CH\u003csub\u003e3\u003c/sub\u003eCN and then placed in a cell with a fresh electrolyte solution for electrochemical characterization. A four-point probe measurement was measured on the Loresta-EP MCP - T360 Mitsubishi, featuring Peltier temperature control.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003e2.3 Synthesis of Poly(benzo[c][\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]thiadiazole-\u003cem\u003ealt\u003c/em\u003e-9,9-dioctyl-9H-fluorene) (Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF)) (P1)\u003c/h2\u003e\u003cp\u003eTo a dry 25 mL single neck round-bottom flask equipped with a magnetic bar, 2 mL of anhydrous toluene were added to dissolve the mixture including 70 mg of (4,7-dibromobenzo[c][\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]thiadiazole) (70 mg, 0.24 mmol, 1.0 eq), 2,2'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) (147 mg, 0.24 mmol, 1.0 eq), Pd(OAc)\u003csub\u003e2\u003c/sub\u003e (5.3 mg, 0.024 mmol, 0.1 eq), P(o-Anisyl)\u003csub\u003e3\u003c/sub\u003e (8.4 mg, 0.024 mmol, 0.1 eq), K\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e (415 mg, 1.9 mmol) under air atmosphere. An Allihn condenser with a standard lower inner drip tip 24/40 joint at the bottom was attached to the flask. Afterwards, the reaction was subjected to stirring and heating up to 120 \u003csup\u003eo\u003c/sup\u003eC using an oil bath in air at a speed of 800 rpm for 24 h. After cooling to room temperature, a solution of 5 N HCl (2 mL) was added to quench the reaction, and the mixture was extracted with toluene. The combined organic layers were washed with brine and diluted water, dried over anhydrous MgSO\u003csub\u003e4\u003c/sub\u003e, and the mixture was filtered and concentrated under reduced pressure. Then, the conjugated polymer was precipitated into cold methanol (100 mL) using a chiller bath. The polymer product, identified as Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) (designated as P1), was isolated through filtration, rinsed with additional methanol, and then dried under vacuum for 24 hours prior to further characterization. The final yield of the conjugated polymer was 94.7 mg, corresponding to an overall yield of 76.09%. \u003csup\u003e1\u003c/sup\u003eH NMR (500 MHz, CDCl\u003csub\u003e3\u003c/sub\u003e), δ (ppm): 8.10 (t, 2H), 8.04 (d, 2H), 7.96 (d, 42H), 7.94 (d, 2H), 7.69 (d, 1H), 2.12 (s, 4H), 1.16\u0026ndash;1.14 (s, 28H), 0.96 (s, 3H), 0.81 (m, 9H). GPC: M\u003csub\u003en\u003c/sub\u003e = 4500 g mol\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. Đ (M\u003csub\u003ew\u003c/sub\u003e/M\u003csub\u003en\u003c/sub\u003e)\u0026thinsp;=\u0026thinsp;1.85.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\u003ch2\u003e\u003cb\u003e2.4 Synthesis of Poly(10-(perylen-3-yl)-10H-phenoxazine-\u003c/b\u003e\u003cb\u003ealt\u003c/b\u003e\u003cb\u003e-9,9-dioctyl-9H-fluorene) (Poly(PPO-\u003c/b\u003e\u003cb\u003ealt\u003c/b\u003e\u003cb\u003e-OF)) (P2)\u003c/b\u003e\u003c/h2\u003e\u003cp\u003e90 mg of 3,7-dibromo-10-(perylen-2-yl)-10H-phenoxazine (0.15 mmol) and 96.3 mg (0.15 mmol) of 2,2'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) was dissolved in 2 mL of pristine reagent-grade toluene in a 100 ml round bottom flask. Then, Pd(OAc)\u003csub\u003e2\u003c/sub\u003e (3.36 mg, 0.015 mmol), P(o-Anisyl)\u003csub\u003e3\u003c/sub\u003e (5.4 mg, 0.015 mmol) and 265 mg of K\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e were added to the reaction. Next, the flask reaction was stirred and heated up to 120 \u003csup\u003eo\u003c/sup\u003eC using an oil bath under an air atmosphere at speed of 800 rpm for 24 h. After cooling to room temperature, a solution of 5 N HCl (2 mL) was added to quenching the mixture reaction, and mixture was extracted with toluene. The combined organic layers were washed with brine and diluted water, dried over anhydrous MgSO\u003csub\u003e4\u003c/sub\u003e, the mixture was filtrated and concentrated under reduced pressure. Then, the conjugated polymer was precipitated in cold methanol (100 ml) using a chiller bath. The polymer product, identified as Poly(PPO-\u003cem\u003ealt\u003c/em\u003e-OF) (designated as P2), was isolated through filtration, rinsed with additional methanol, and then dried under vacuum for 24 hours prior to further characterization. The final yield of the conjugated polymer was 91.8 mg, corresponding to an overall yield of 73.55%. \u003csup\u003e1\u003c/sup\u003eH NMR (500 MHz, CDCl\u003csub\u003e3\u003c/sub\u003e), δ (ppm): 8.39\u0026ndash;8.28 (m, 4H), 7.97 (s, 1H), 7.75\u0026ndash;7.46 (m, 10H), 7.16 (s, 2H), 6.90 (d, 2H), 6.01 (d, 2H), 1.96 (s, 4H), 1.53\u0026ndash;0.67 (m, 30H). GPC: M\u003csub\u003en\u003c/sub\u003e = 7600 g mol\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. Đ (M\u003csub\u003ew\u003c/sub\u003e/M\u003csub\u003en\u003c/sub\u003e)\u0026thinsp;=\u0026thinsp;1.55.\u003c/p\u003e\u003c/div\u003e"},{"header":"3. Results and discussion","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003e3.1 Synthesis of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt\u003c/em\u003e-OF) conjugated polymers\u003c/h2\u003e\u003cp\u003eThe synthesis procedure to prepare two conjugated polymers based on 9,9-dioctyl-9H-fluorene with 10-(perylen-2-yl)-10H-phenoxazine and benzo[c][\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]thiadiazole was illustrated in Scheme \u003cspan refid=\"Sch1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. In the initial stage, dibrominated N-perylenephenoxazine monomer was synthesized from commercially available phenoxazine and perylene via three steps in a good yield of 67% [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. The polymer Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) was synthesized using 4,7-dibromobenzo[c][\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]thiadiazole and 2,2'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) with 1:1 molar ratio. This polymerization was carried out via Pd-catalyzed Suzuki polycondensation under aerobic conditions, where Pd(OAc)\u003csub\u003e2\u003c/sub\u003e, P(o-Anisyl)\u003csub\u003e3\u003c/sub\u003e, and K\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e were used as the catalyst, ligand, additive, and base, respectively. In the case of Poly(PPO-\u003cem\u003ealt\u003c/em\u003e-OF), it was synthesized from 3,7-dibromo-10-(perylen-2-yl)-10H-phenoxazine and 2,2'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) in 1:1 molar ratio., following the same aerobic conditions of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe polymers were extracted through Soxhlet extraction with chloroform to obtain the soluble fractions, which accounted for 65.4% of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and 91.2% of Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) by weight. The insoluble fractions constituted approximately 34.6% and 8.8% for Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF), respectively. The obtained conjugated polymers were characterized by GPC to determine their average molecular weights. Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) exhibited a number-average molecular weight (M\u003csub\u003en\u003c/sub\u003e) of 4500 g mol\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e with dispersity (Đ) of 1.85, while Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) showed an M\u003csub\u003en\u003c/sub\u003e of 7600 g mol\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e with Đ of 2.55 (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb). This suggests that P2 exhibits weaker π\u0026ndash;π stacking interactions than P1 because it incorporates a nonplanar phenoxazine (PXZ) unit into its conjugated backbone [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e].\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe chemical structures of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) were characterized by FT-IR (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea) and \u003csup\u003e1\u003c/sup\u003eH NMR spectroscopies (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). In the FT-IR spectrum of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF), a notable peak was observed at 513 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, which is attributed to the N-S linker associated with the thiadiazole moieties. Additional peaks at 818 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 1260 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e correspond to the C-H and C\u0026thinsp;=\u0026thinsp;N of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF). Typical bands, from 2853 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 3030 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, are assigned to the C\u0026ndash;H stretching vibrations of the octyl groups of 9,9-dioctyl-9H-fluorene-2,7-diyl moieties. The peak recorded at 1460 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e signifies the presence of C\u0026thinsp;=\u0026thinsp;C aromatic bonds within the main chain of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF). In the FT-IR spectrum of Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF), the peaks at 1340 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 1260 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e are ascribed to the C-N and C-O bonding of phenoxazine units, respectively. The peaks in the region from 2853 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 3050 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e indicate C\u0026ndash;H stretching vibrations. Overall, the FT-IR spectra of both Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) exhibited all of their structural characteristic peaks. The analysis of the \u003csup\u003e1\u003c/sup\u003eH NMR spectrum of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) revealed the peaks ranging from 8.04 ppm to 7.69 ppm, which correspond to the aromatic region of benzo[c][\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]thiadiazole and fluorene moieties (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). A multiplet observed at 2.1 ppm is attributed to the methylene protons from the octyl side chain. Additionally, peaks between 0.81 ppm and 1.16 ppm are associated with protons in the aliphatic side chains. In the case of Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF), peaks from 6.90 ppm and 8.39 ppm correspond to the protons of aromatic rings of phenoxazine, perylene, and fluorene moieties (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). A distinct peak at 6.01 ppm is assigned to the \u0026ldquo;l\u0026rdquo; and \u0026ldquo;m\u0026rdquo; positions of the phenoxazine ring, while the peak at 1.96 ppm is the methylene protons from the octyl side chain. In addition, the peaks from 0.67 ppm to 1.53 ppm are attributed to the protons in octyl side chains. Overall, both Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) exhibit all characteristic peaks in their \u003csup\u003e1\u003c/sup\u003eH NMR spectra. The analysis results from FT-IR, GPC, and \u003csup\u003e1\u003c/sup\u003eH NMR confirm that these polymers have been successfully synthesized via Suzuki polycondensation under aerobic conditions.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\u003ch2\u003e3.2 Optical and electrochemical properties Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt\u003c/em\u003e-OF) conjugated polymers.\u003c/h2\u003e\u003cp\u003ePoly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) demonstrated good solubility in a wide range of organic solvents, including tetrahydrofuran (THF), chloroform, chlorobenzene, and toluene. The absorption intensity and maximum absorption wavelength of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) were measured using UV-Vis spectroscopy in three different solvents \u0026ndash; THF, CHCl\u003csub\u003e3\u003c/sub\u003e, and toluene (C\u003csub\u003eM\u003c/sub\u003e: ~ 10 \u0026micro;M) \u0026ndash; as well as in solid-state thin films prepared by the spin coating method. In Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea, it is observed that Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) exhibits two absorption peaks at λ\u0026thinsp;=\u0026thinsp;319 nm and 446 nm in all organic solutions, and a slightly red shift to 466 nm in thin film form. Similarly, Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) shows a maximum absorption at 417 nm in solvents and 422 nm in thin film (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eb). Notably, both polymers do not exhibit a red shift in the solid-state thin film compared to solutions in non-polar solvents, indicating that intermolecular interactions of conjugated polymers is not significantly strengthened due to the presence of long alkyl side chains [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. The optical bandgaps of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) were determined to be 2.25 eV and 2.06 eV, respectively, based on their λ\u003csub\u003eonset\u003c/sub\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe photoluminescent spectra (PL) of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) were recorded in different solvents, including THF, CHCl\u003csub\u003e3\u003c/sub\u003e, and toluene, at a concentration of 1 \u0026micro;M. Emission wavelengths of the polymers were measured under excitation at 365 nm. Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) exhibited a peak at 534 nm (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ea), while Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) displayed a peak at 634 nm (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eb). The fluorescence quantum yields (ФF) of both polymers in dilute CHCl\u003csub\u003e3\u003c/sub\u003e solutions were evaluated using the integrating sphere method, in comparison to 9,10-diphenylanthracene standard (ФF\u0026thinsp;=\u0026thinsp;0.9). The ФF values of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) were determined to be 0.27 and 0.38, respectively, indicating that Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) has a stronger π\u0026ndash;π stacking effect compared to Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn addition, thin films of studied polymers were prepared on ITO glasses (with a resistance of 5 Ω per square) by the spin-coating method at 1500 rpm using a special Teflon spin-coater from Laurell WS-400 to avoid the electrostatic effects on the surfaces of the films. The fluorescence properties of these thin films were investigated by exciting them at a wavelength of 365 nm using an integrated sphere spectrophotometer. Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) showed an emission peak at 539 nm. In comparison, Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) displayed an emission peak at 600 nm (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). These results indicate that the fluorescence emission of the synthesized polymers in the solid state closely resembles that of polymer solutions, suggesting that the π\u0026ndash;π stacking characteristic of these polymers does not significantly affect their luminescence properties [\u003cspan additionalcitationids=\"CR38\" citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e].\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eNext, reflectance spectroscopy was employed to examine the transmission characteristics of the studied polymers under visible light using the Ocean Optic USB400 spectrometer. Both Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) exhibited transmission rates exceeding 80% from 525 nm to 850 nm (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e). In contrast, these polymers showed transmission rates from 30\u0026ndash;70% at wavelengths below 500 nm. This finding suggests that the conjugated polymer layers are suitable for applications in transmittance displays for electronic devices [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e].\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eTo get deeper insights into the optical properties, the thin films of these conjugated polymers were investigated using CRAI microscopy spectroscopy instruments. Figure\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003e illustrates the transmission spectroscopy of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) at various points on a spin-coated film, ranging from the center to the edge. It is evident that the transmission at the center (red line) exceeds 90%, significantly higher than that of the outer positions (black line and blue line). This can be attributed to the fact that the thickness of the film at the center is considerably thinner than at the edges. Figure\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003e presents the microscopy transmission spectroscopy of Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF), which displays a spectrum similar to that of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF). In the center area, the thin film demonstrates a transparency greater than 90%, whereas the transparency in the outer regions remains below 90%. These results indicate that the uniformity of thin films composed of the studied polymers significantly impacts their absorption and transmission properties.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe electrochemical properties of the studied polymers were measured by cyclic voltammetry (CV) to elucidate their redox properties. The CV experiments of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) were conducted in acetonitrile, utilizing an Ag/Ag\u003csup\u003e+\u003c/sup\u003e as reference electrode, a platinum wire as counter electrode, and a conjugated polymer coated on a Pt disc as working electrode. All reported potentials were referenced to the Ag/Ag\u003csup\u003e+\u003c/sup\u003e electrode (0.1 M AgNO\u003csub\u003e3\u003c/sub\u003e/ 0.1 M TBAPF\u003csub\u003e6\u003c/sub\u003e in CH\u003csub\u003e3\u003c/sub\u003eCN; 0.320 V vs. SCE), and the measurements were internally standardized with ferrocene (vs. Ag/Ag +). The scan rate was set at 50 mV s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e with V\u003csub\u003emax\u003c/sub\u003e = \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\pm\\:\\)\u003c/span\u003e\u003c/span\u003e 2V. The cyclic voltammogram of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) exhibited a reduction peak at -0.69 V and an oxidation peak at +\u0026thinsp;1.49 V, which corresponded to a HOMO energy level of -5.89 eV (Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e10\u003c/span\u003ea). For Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF), it possessed a reduction peak at -0.67 V and an oxidation peak at +\u0026thinsp;0.80 V, which attributed to a HOMO energy level of \u0026minus;\u0026thinsp;5.20 eV (Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e10\u003c/span\u003eb). The LUMO energy levels of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) were determined based on the HOMO levels and their optical band gaps, to be -3.71 eV and \u0026minus;\u0026thinsp;3.73 eV, respectively. A comprehensive summary of the HOMO and LUMO levels, along with the estimated band gaps of studied polymers, is presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eElectrochemical properties of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF).\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePolymers\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eE\u003csub\u003eox\u003c/sub\u003e\u003csup\u003e\u003cem\u003eonset\u003c/em\u003e\u003c/sup\u003e (V)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eE\u003csub\u003eg\u003c/sub\u003e (eV)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHOMO (eV)\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eLUMO (eV)\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eSheet Resistance (Ω/sq)\u003csup\u003ee\u003c/sup\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePoly(BT-\u003cem\u003ealt\u003c/em\u003e-OF)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1.49\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e-5.89\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e-3.64\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e2.68\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePoly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026minus;\u0026thinsp;5.20\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e-3.14\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e2.73\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003csup\u003ea\u003c/sup\u003e Onset oxidation potential vs Ag/AgCl. \u003csup\u003eb\u003c/sup\u003e Estimated from the onset of absorption edge. \u003csup\u003ec\u003c/sup\u003e Estimated from the onset oxidation potential. \u003csup\u003ed\u003c/sup\u003e Deduced from HOMO and E\u003csub\u003eg\u003c/sub\u003e. \u003csup\u003ee\u003c/sup\u003e Room temperature (25\u003csup\u003eo\u003c/sup\u003eC).\u003c/p\u003e\u003cp\u003eThe sheet resistance of the thin films was measured by a four-point probe method using a Mitsubishi Loresta-EP MCP-T360 apparatus. The sheet resistances of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) were recorded at approximately 12.83 Ω sq\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 14.09 Ω sq\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e at 25 \u003csup\u003eo\u003c/sup\u003eC. Further measurements demonstrated the variation of sheet resistance with temperature; specifically, the sheet resistance of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) decreased from 12.83 Ω sq\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e at 25 \u003csup\u003eo\u003c/sup\u003eC to 11.47 Ω sq\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e at 0 \u003csup\u003eo\u003c/sup\u003eC, while Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) exhibited a similar trend, declining from 13.01 Ω sq\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e at 25 \u003csup\u003eo\u003c/sup\u003eC to 11.04 Ω sq\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e at 0 \u003csup\u003eo\u003c/sup\u003eC (Fig.\u0026nbsp;\u003cspan refid=\"Fig11\" class=\"InternalRef\"\u003e11\u003c/span\u003e). This observed decrease in sheet resistance at lower temperatures can be attributed to aggregation phenomena that enhance the conductivity of conjugated polymers. However, as the temperature was reduced further to -5 \u003csup\u003eo\u003c/sup\u003eC, there was an increase in the sheet resistance of polymer thin films. This finding can be explained by the onset of moisture freezing on the surface, adversely affecting the conductivity of the polymer films.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\u003ch2\u003e3.3 Nitroaromatic explosives detection\u003c/h2\u003e\u003cp\u003eNext, we attempt to investigate the sensing capabilities of these two conjugated polymers, Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF), for the detection of nitroaromatic-based explosives, specifically 2,4,6-trinitrotoluene (TNT), Dinitrotoluene (DNT), Nitrobenzene (NB), 4-Nitrophenol (NP), and picric acid (PA). An optimization experiment was conducted to assess the fluorescence emission intensity of both polymers at a concentration of 1 \u0026micro;M in THF. The results showed that the PL intensity reached 830 a.u and 400 a.u for poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF), respectively, under excitation at 365 nm (Fig.\u0026nbsp;\u003cspan refid=\"Fig12\" class=\"InternalRef\"\u003e12\u003c/span\u003ea and Fig.\u0026nbsp;\u003cspan refid=\"Fig13\" class=\"InternalRef\"\u003e13\u003c/span\u003ea). To quantitatively evaluate the sensitivity of both polymers toward nitroaromatic explosive detection, solutions of nitroaromatics in THF were prepared at 10\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e M. Incremental additions of 20 \u0026micro;L of each nitroaromatic compound were made to the polymer solution within a quartz cuvette, followed by the recording of the emission spectra. As observed in Fig.\u0026nbsp;\u003cspan refid=\"Fig12\" class=\"InternalRef\"\u003e12\u003c/span\u003ea and Fig.\u0026nbsp;\u003cspan refid=\"Fig13\" class=\"InternalRef\"\u003e13\u003c/span\u003ea, the addition of nitroaromatic compounds led to a decrease in the PL intensity of the polymers. Among the investigated nitroaromatic compounds, picric acid exhibited the most pronounced fluorescence quenching efficiencies on both conjugated polymers. The fluorescence quenching efficiencies were measured at 15.6% for Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and 37.5% for Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) upon the addition of 20 \u0026micro;L of PA solution. The findings establish that picric acid possesses a significant capacity to quench the fluorescence of both polymers: Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) showed the quenching trend of PA\u0026thinsp;\u003cem\u003e\u0026gt;\u0026thinsp;\u0026gt;\u003c/em\u003e\u0026thinsp;2,4-DNP\u0026thinsp;\u0026asymp;\u0026thinsp;4-NP\u0026thinsp;\u003cem\u003e\u0026gt;\u003c/em\u003e\u0026thinsp;TNT\u0026thinsp;\u0026asymp;\u0026thinsp;NB, while Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) demonstrated PA \u003cem\u003e\u0026gt;\u0026gt;\u0026gt;\u003c/em\u003e 2,4-DNP\u0026thinsp;\u003cem\u003e\u0026gt;\u003c/em\u003e\u0026thinsp;TNT\u0026thinsp;\u0026asymp;\u0026thinsp;4-NP\u0026thinsp;\u0026asymp;\u0026thinsp;NB. Therefore, picric acid was selected as the analyzer target for the fluorescence quenching mechanism. Figure\u0026nbsp;\u003cspan refid=\"Fig12\" class=\"InternalRef\"\u003e12\u003c/span\u003eb illustrates that as the volume of PA increased from 0 to 200 \u0026micro;L, the PL intensity of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) solution decreased to 18%, corresponding to the quenching fluorescence value of 82%. In contrast, the PL intensity of Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) solution decreased to 10%, reflecting the quenching fluorescence of 92% (Fig.\u0026nbsp;\u003cspan refid=\"Fig13\" class=\"InternalRef\"\u003e13\u003c/span\u003eb).\u003c/p\u003e\u003cp\u003eBesides, the quenching constant, Ksv, was calculated using the Stern-Volmer formula: I\u003csub\u003eo\u003c/sub\u003e/I\u0026thinsp;=\u0026thinsp;1\u0026thinsp;+\u0026thinsp;K\u003csub\u003esv\u003c/sub\u003e. C\u003csub\u003ePA\u003c/sub\u003e can be applied to estimate the efficiency of detection of PA, where I\u003csub\u003eo\u003c/sub\u003e and I are the fluorescence intensities before and after the presence of PA, C\u003csub\u003ePA\u003c/sub\u003e is the PA compound concentration, and K\u003csub\u003eSV\u003c/sub\u003e is the Stern-Volmer constant. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig12\" class=\"InternalRef\"\u003e12\u003c/span\u003ec, the K\u003csub\u003eSV\u003c/sub\u003e value of Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) was estimated to be 8.48 x 10\u003csup\u003e2\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, with the limit of detection (LOD) of 6.91 x 10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e M. Meanwhile, Fig.\u0026nbsp;\u003cspan refid=\"Fig13\" class=\"InternalRef\"\u003e13\u003c/span\u003ec indicated that the K\u003csub\u003eSV\u003c/sub\u003e value of Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) was 3.08 x 10\u003csup\u003e3\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, with an LOD of 3.31 x 10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e M. These findings demonstrate that both conjugated polymers exhibit high sensitivity to PA, surpassing the response of other nitroaromatic compounds. Moreover, the rapid and clearly visible fluorescence quenching responses of the conjugated polymers toward PA at low concentrations were distinctly observed under UV irradiation at 365 nm (see Fig.\u0026nbsp;\u003cspan refid=\"Fig12\" class=\"InternalRef\"\u003e12\u003c/span\u003ed and Fig.\u0026nbsp;\u003cspan refid=\"Fig13\" class=\"InternalRef\"\u003e13\u003c/span\u003ed).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eTo archive the applicable process, the test papers are prepared for user in real-life situations. Filter papers (1 cm x 1 cm) were soaked in a polymer solution in THF (C\u003csub\u003eM\u003c/sub\u003e = 10\u003csup\u003e\u0026minus;\u0026thinsp;3\u003c/sup\u003e M) for 15 minutes, then dried and examined under a UV lamp (365 nm). The fluorescence emission properties of both conjugated polymers remained stable over 10 days, demonstrating that the polymer chains were effectively impregnated into the filter test papers. These impregnated papers were then used to detect nitro-explosives by sequentially dripping (5 \u0026micro;L) solutions containing NACs, including PA, 2,4-DNP, TNT, NP, and NB (C\u003csub\u003eM\u003c/sub\u003e = 10\u003csup\u003e\u0026minus;\u0026thinsp;3\u003c/sup\u003e M). As illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig14\" class=\"InternalRef\"\u003e14\u003c/span\u003e, Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) are suitable for PA detection, showing a black spot of quenching at concentrations of 10\u003csup\u003e\u0026minus;\u0026thinsp;3\u003c/sup\u003e M and demonstrating sensitivity down to low concentrations of 10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e M. This study confirmed that Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) in solid-state can recognize PA with high sensitivity and selectivity.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003eIn this study, two fluorescent conjugated polymers, Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF) with average molecular weights of 5000 g mol\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, were designed and synthesized successfully using a modified Suzuki polymerization method under aerobic conditions. This approach opens up a simple new pathway for the synthesis of novel conjugated polymers where Suzuki reactions are applicable. The obtained conjugated polymers were thoroughly characterized in terms of their chemical structure, as well as their optical and thermal properties, both in solution and solid-state thin films. In addition, the polymers demonstrated high sensitivity to PA in fluorescence quenching with K\u003csub\u003eSV\u003c/sub\u003e constants of 8.48 x 10\u003csup\u003e2\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for Poly(BT-\u003cem\u003ealt\u003c/em\u003e-OF) and 3.08 x 10\u003csup\u003e3\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for Poly(PPO-\u003cem\u003ealt-\u003c/em\u003eOF), respectively. The detection limits for PA were determined to be approximately 6.91 x 10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e M and 3.31 x 10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e M, respectively. Furthermore, polymer-based filter papers were prepared and tested for practical applications, demonstrating effective detection of PA at low concentrations of 10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e M. This study highlights promising materials and a potential method for selective, rapid, and trace determination of nitro-explosives using fluorescent polymers.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research was supported by the Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number \u0026ldquo;104.02-2023.102\u0026rdquo;. The author thanks\u0026nbsp;Key Laboratory for Polymer and Composite Materials, Viet Nam National University Ho Chi Minh City\u0026nbsp;for their support to carry out this work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number \u0026ldquo;104.02-2023.102\u0026rdquo;.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eContributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLuan Thanh Nguyen:\u0026nbsp;\u003c/strong\u003eWriting \u0026ndash; original draft, Methodology, Investigation, Formal analysis. \u003cstrong\u003eThanh Tien Nguyen:\u0026nbsp;\u003c/strong\u003eSoftware, Methodology, Investigation, Formal analysis. \u003cstrong\u003eMinh Duy Hoang:\u0026nbsp;\u003c/strong\u003eSoftware, Methodology, Investigation, Formal analysis. \u003cstrong\u003eTam Hoang Luu:\u0026nbsp;\u003c/strong\u003eMethodology, Investigation, Formal analysis. \u003cstrong\u003eLe- Thu Thi Nguyen:\u0026nbsp;\u003c/strong\u003eWriting \u0026ndash; review \u0026amp; editing, Validation, Software, Formal analysis. \u003cstrong\u003eHai Le Tran:\u0026nbsp;\u003c/strong\u003eMethodology, Investigation, Formal analysis. \u003cstrong\u003eTin Chanh Duc Doan\u003c/strong\u003e: Software, Methodology, Investigation, Formal analysis. \u003cstrong\u003eChau Duc Tran\u003c/strong\u003e: Writing \u0026ndash; review \u0026amp; editing, Validation, Supervision, Resources, Project administration, Methodology, Funding acquisition.\u003cstrong\u003e\u0026nbsp;Tam Huu Nguyen:\u0026nbsp;\u003c/strong\u003eWriting \u0026ndash; review, Methodology, Investigation, Formal analysis, Data curation, Conceptualization. \u003cstrong\u003eHa Tran Nguyen:\u0026nbsp;\u003c/strong\u003eWriting \u0026ndash; review \u0026amp; editing, Writing \u0026ndash; original draft, Validation, Supervision, Conceptualization.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics declarations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData will be made available on request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eThomas SW, Joly GD, Swager TM (2007) Chemical Sensors Based on Amplifying Fluorescent Conjugated Polymers. Chem Rev 107:1339\u0026ndash;1386. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/cr0501339\u003c/span\u003e\u003cspan address=\"10.1021/cr0501339\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSun X, Wang Y, Lei Y (2015) Fluorescence based explosive detection: from mechanisms to sensory materials. Chem Soc Rev 44:8019\u0026ndash;8061. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1039/C5CS00496A\u003c/span\u003e\u003cspan address=\"10.1039/C5CS00496A\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSalinas Y, Mart\u0026iacute;nez-M\u0026aacute;\u0026ntilde;ez R, Marcos MD, Sancen\u0026oacute;n F, Costero AM, Parra M et al (2012) Optical chemosensors and reagents to detect explosives. ChSRv 41:1261\u0026ndash;1296. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1039/C1CS15173H\u003c/span\u003e\u003cspan address=\"10.1039/C1CS15173H\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBilal M, Bagheri AR, Bhatt P, Chen S (2021) Environmental occurrence, toxicity concerns, and remediation of recalcitrant nitroaromatic compounds. J Environ Manage 291:112685. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jenvman.2021.112685\u003c/span\u003e\u003cspan address=\"10.1016/j.jenvman.2021.112685\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTiwari J, Tarale P, Sivanesan S, Bafana A (2019) Environmental persistence, hazard, and mitigation challenges of nitroaromatic compounds. Environ Sci Pollut Res 26:28650\u0026ndash;28667. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s11356-019-06043-8\u003c/span\u003e\u003cspan address=\"10.1007/s11356-019-06043-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eForbes TP, Sisco E (2018) Recent advances in ambient mass spectrometry of trace explosives. Analyst 143:1948\u0026ndash;1969. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1039/C7AN02066J\u003c/span\u003e\u003cspan address=\"10.1039/C7AN02066J\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTo KC, Ben-Jaber S, Parkin IP (2020) Recent Developments in the Field of Explosive Trace Detection. ACS Nano 14:10804\u0026ndash;10833. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acsnano.0c01579\u003c/span\u003e\u003cspan address=\"10.1021/acsnano.0c01579\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMohammed A-FA, Nabat KY, Jiang T, Liu L (2025) Recent innovations in explosive trace detection: Advances and emerging technologies. Trends Environ Anal Chem 46:e00261. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.teac.2025.e00261\u003c/span\u003e\u003cspan address=\"10.1016/j.teac.2025.e00261\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMartelo LM, Marques LF, Burrows HD, Berberan-Santos MN (2019) Explosives Detection: From Sensing to Response. Springer International Publishing, Cham\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCaygill JS, Davis F, Higson SPJ (2012) Current trends in explosive detection techniques. Talanta 88:14\u0026ndash;29. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.talanta.2011.11.043\u003c/span\u003e\u003cspan address=\"10.1016/j.talanta.2011.11.043\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDe Iacovo A, Mitri F, De Santis S, Giansante C, Colace L (2024) Colloidal Quantum Dots for Explosive Detection: Trends and Perspectives. ACS Sens 9:555\u0026ndash;576. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acssensors.3c02097\u003c/span\u003e\u003cspan address=\"10.1021/acssensors.3c02097\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSong JH, Kang DW (2023) Hazardous nitroaromatic explosives detection by emerging porous solid sensors. Coord Chem Rev 492:215279. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ccr.2023.215279\u003c/span\u003e\u003cspan address=\"10.1016/j.ccr.2023.215279\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLustig WP, Mukherjee S, Rudd ND, Desai AV, Li J, Ghosh SK (2017) Metal\u0026ndash;organic frameworks: functional luminescent and photonic materials for sensing applications. ChSRv 46:3242\u0026ndash;3285. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1039/C6CS00930A\u003c/span\u003e\u003cspan address=\"10.1039/C6CS00930A\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHe W, Duan J, Liu H, Qian C, Zhu M, Zhang W et al (2024) Conjugated microporous polymers for advanced chemical sensing applications. Prog Polym Sci 148:101770. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.progpolymsci.2023.101770\u003c/span\u003e\u003cspan address=\"10.1016/j.progpolymsci.2023.101770\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eXiaofu Wu HT, Lixiang W (2019) Fluorescent Polymer Materials for Detection of Explosives. Progress Chem 31:1509\u0026ndash;1527. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.7536/pc190734\u003c/span\u003e\u003cspan address=\"10.7536/pc190734\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRochat S, Swager TM (2013) Conjugated Amplifying Polymers for Optical Sensing Applications. ACS Appl Mater Interfaces 5:4488\u0026ndash;4502. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/am400939w\u003c/span\u003e\u003cspan address=\"10.1021/am400939w\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSwager TM (1998) The Molecular Wire Approach to Sensory Signal Amplification. Acc Chem Res 31:201\u0026ndash;207. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/ar9600502\u003c/span\u003e\u003cspan address=\"10.1021/ar9600502\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZen Eddin M, Zhilina EF, Chuvashov RD, Dubovik AI, Mekhaev AV, Chistyakov KA et al (2022) Random Copolymers of Styrene with Pendant Fluorophore Moieties: Synthesis and Applications as Fluorescence Sensors for Nitroaromatics. Molecules 27:6957\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLiu W, Chen H, Zhang S, Li P, Wu W (2024) Synthesis of Novel Fluorescent Conjugated Polymers and Their Rapid Gas-Phase Detection of Trace Nitro-Explosives. Macromol Chem Phys 225:2300325. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1002/macp.202300325\u003c/span\u003e\u003cspan address=\"10.1002/macp.202300325\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHaque MH, Koh K, Sohn H (2023) Detection of TNT Vapors by Fluorescence Quenching and Self-Recovery Using Highly Fluorescent Conjugated Silole Polymers. Macromolecules 56:6396\u0026ndash;6406. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acs.macromol.2c02193\u003c/span\u003e\u003cspan address=\"10.1021/acs.macromol.2c02193\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLo CK, Wolfe RMW, Reynolds JR (2021) From Monomer to Conjugated Polymer: A Perspective on Best Practices for Synthesis. Chem Mater 33:4842\u0026ndash;4852. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acs.chemmater.1c01142\u003c/span\u003e\u003cspan address=\"10.1021/acs.chemmater.1c01142\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDing L, Yu Z-D, Wang X-Y, Yao Z-F, Lu Y, Yang C-Y et al (2023) Polymer Semiconductors: Synthesis, Processing, and Applications. Chem Rev 123:7421\u0026ndash;7497. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acs.chemrev.2c00696\u003c/span\u003e\u003cspan address=\"10.1021/acs.chemrev.2c00696\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePhan S, Luscombe CK (2019) Recent Advances in the Green, Sustainable Synthesis of Semiconducting Polymers. Trends in Chemistry 1:670\u0026thinsp;\u0026ndash;\u0026thinsp;81. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.trechm.2019.08.002\u003c/span\u003e\u003cspan address=\"10.1016/j.trechm.2019.08.002\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHuu Nguyen T, Le Tran H, Minh Phan H, Duy Hoang M, Nguyen L-TT, Chanh Duc Doan T et al (2024) Toward rapid and efficient protocols: Synthesis of benzotriazole-based π-conjugated polymers via direct arylation polycondensation under aerobic conditions. Eur Polym J 219:113369. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.eurpolymj.2024.113369\u003c/span\u003e\u003cspan address=\"10.1016/j.eurpolymj.2024.113369\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCarlucci C, Conelli D, Hassan Omar O, Margiotta N, Grisorio R, Suranna GP (2023) Toward eco-friendly protocols: insights into direct arylation polymerizations under aerobic conditions in anisole. Polym Chem 14:343\u0026ndash;351. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1039/D2PY01214F\u003c/span\u003e\u003cspan address=\"10.1039/D2PY01214F\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eIchige A, Saito H, Kuwabara J, Yasuda T, Choi J-C, Kanbara T (2018) Facile Synthesis of Thienopyrroledione-Based π-Conjugated Polymers via Direct Arylation Polycondensation under Aerobic Conditions. Macromolecules 51:6782\u0026ndash;6788. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acs.macromol.8b01289\u003c/span\u003e\u003cspan address=\"10.1021/acs.macromol.8b01289\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSanzone A, Calascibetta A, Monti M, Mattiello S, Sassi M, Corsini F et al (2020) Synthesis of Conjugated Polymers by Sustainable Suzuki Polycondensation in Water and under Aerobic Conditions. ACS Macro Lett 9:1167\u0026ndash;1171. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acsmacrolett.0c00495\u003c/span\u003e\u003cspan address=\"10.1021/acsmacrolett.0c00495\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBezgin Carbas B (2022) Fluorene based electrochromic conjugated polymers: A review. Poly 254:125040. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.polymer.2022.125040\u003c/span\u003e\u003cspan address=\"10.1016/j.polymer.2022.125040\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAl-Sharji H, Ilmi R, Khan MS (2024) Recent Progress in Phenoxazine-Based Thermally Activated Delayed Fluorescent Compounds and Their Full-Color Organic Light-Emitting Diodes. Top Curr Chem 382:5. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s41061-024-00450-3\u003c/span\u003e\u003cspan address=\"10.1007/s41061-024-00450-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBorissov A, Maurya YK, Moshniaha L, Wong W-S, Żyła-Karwowska M, Stępień M (2022) Recent Advances in Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds. Chem Rev 122:565\u0026ndash;788. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acs.chemrev.1c00449\u003c/span\u003e\u003cspan address=\"10.1021/acs.chemrev.1c00449\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCong P, Wang Z, Geng Y, Meng Y, Meng C, Chen L et al (2023) Benzothiadiazole-based polymer donors. Nano Energy 105:108017. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.nanoen.2022.108017\u003c/span\u003e\u003cspan address=\"10.1016/j.nanoen.2022.108017\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNguyen CHT, Nguyen TH, Nguyen TPL, Le Tran H, Luu TH, Tran CD et al (2023) Aerobic direct arylation polycondensation of N-perylenyl phenoxazine-based fluorescent conjugated polymers for highly sensitive and selective TNT explosives detection. Dyes Pigm 219:111613. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.dyepig.2023.111613\u003c/span\u003e\u003cspan address=\"10.1016/j.dyepig.2023.111613\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDos Santos JM, Hall D, Basumatary B, Bryden M, Chen D, Choudhary P et al (2024) The Golden Age of Thermally Activated Delayed Fluorescence Materials: Design and Exploitation. Chem Rev 124:13736\u0026ndash;14110. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acs.chemrev.3c00755\u003c/span\u003e\u003cspan address=\"10.1021/acs.chemrev.3c00755\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMei J, Bao Z (2014) Side Chain Engineering in Solution-Processable Conjugated Polymers. Chem Mater 26:604\u0026ndash;615. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/cm4020805\u003c/span\u003e\u003cspan address=\"10.1021/cm4020805\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLuo N, Ren P, Feng Y, Shao X, Zhang H-L, Liu Z (2022) Side-Chain Engineering of Conjugated Polymers for High-Performance Organic Field-Effect Transistors. J Phys Chem Lett 13:1131\u0026ndash;1146. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acs.jpclett.1c03909\u003c/span\u003e\u003cspan address=\"10.1021/acs.jpclett.1c03909\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWelscher PJ, Ziener U, Kuehne AJC (2025) Fluorene Oligomers Featuring a Central 2,1,3-Benzothiadiazole Unit with High Photoluminescence Quantum Yield and Amplified Spontaneous Emission. Macromolecules 58:2730\u0026ndash;2735. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acs.macromol.4c03110\u003c/span\u003e\u003cspan address=\"10.1021/acs.macromol.4c03110\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYe S, Bao Y (2024) Recent Advances in Fluorescent Polymers with Color-Tunable Aggregate Emission. Chem Mater 36:5878\u0026ndash;5896. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acs.chemmater.3c02714\u003c/span\u003e\u003cspan address=\"10.1021/acs.chemmater.3c02714\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBelmonte-V\u0026aacute;zquez JL, Amador-S\u0026aacute;nchez YA, Rodr\u0026iacute;guez-Cort\u0026eacute;s LA, Rodr\u0026iacute;guez-Molina B (2021) Dual-State Emission (DSE) in Organic Fluorophores: Design and Applications. Chem Mater 33:7160\u0026ndash;7184. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acs.chemmater.1c02460\u003c/span\u003e\u003cspan address=\"10.1021/acs.chemmater.1c02460\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGon M, Tanaka K, Chujo Y (2023) π-Conjugated polymers based on flexible heteroatom-containing complexes for precise control of optical functions. Polym J 55:723\u0026ndash;734. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/s41428-023-00779-4\u003c/span\u003e\u003cspan address=\"10.1038/s41428-023-00779-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNair NM, Zumeit A, Dahiya R (2025) Transparent and Transient Flexible Electronics. Adv Sci 12:e05133. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1002/advs.202505133\u003c/span\u003e\u003cspan address=\"10.1002/advs.202505133\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Schemes","content":"\u003cp\u003eScheme 1 is available in the Supplementary Files section\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"journal-of-polymer-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jpol","sideBox":"Learn more about [Journal of Polymer Research](https://www.springer.com/journal/10965)","snPcode":"10965","submissionUrl":"https://www.editorialmanager.com/jpol/","title":"Journal of Polymer Research","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Conjugated polymer, Phenoxazine, Perylene, Fluorene, Aerobic polycondensation, Picric acid detection","lastPublishedDoi":"10.21203/rs.3.rs-7460772/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7460772/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe detection and discrimination of nitroaromatic compounds (NACs) are crucial for ensuring environmental safety and national security. Compounds like Picric acid (PA) and its derivatives are primarily released into the environment through coal mining activities, military activities, and various industrial chemical synthesis processes. These substances not only contribute significantly to the pollution of soil, water, and air, but they also pose serious risks to human health and living organisms due to their potential to cause mutations and cancer. In this research, we synthesized two conjugated polymers based on phenoxazine bearing perylene as a side chain and benzo[c][\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]thiadiazole with fluorene backbone as co-monomers, and developed an efficient fluorescence sensor employing them. This work presents a novel approach for tracing nitroaromatic compounds, including 2,4,6-trinitrotoluene (TNT), 2,4-Dinitrotoluene (DNT), Nitrobenzene (NB), 4-Nitrophenol (NP), and PA.\u003c/p\u003e","manuscriptTitle":"N-perylenyl phenoxazine and fluorene-based conjugated copolymer as a potential fluorescent probe for nitroaromatic explosives detection","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-15 09:27:00","doi":"10.21203/rs.3.rs-7460772/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2025-10-02T05:07:59+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-10-02T04:56:21+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"Journal of Polymer Research","date":"2025-09-12T15:15:15+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-28T00:47:25+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Polymer Research","date":"2025-08-27T03:29:44+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-polymer-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jpol","sideBox":"Learn more about [Journal of Polymer Research](https://www.springer.com/journal/10965)","snPcode":"10965","submissionUrl":"https://www.editorialmanager.com/jpol/","title":"Journal of Polymer Research","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"9ec847f9-c630-49a4-98a8-4f2072d22427","owner":[],"postedDate":"October 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-11-17T16:09:13+00:00","versionOfRecord":{"articleIdentity":"rs-7460772","link":"https://doi.org/10.1007/s10965-025-04664-x","journal":{"identity":"journal-of-polymer-research","isVorOnly":false,"title":"Journal of Polymer Research"},"publishedOn":"2025-11-10 15:58:37","publishedOnDateReadable":"November 10th, 2025"},"versionCreatedAt":"2025-10-15 09:27:00","video":"","vorDoi":"10.1007/s10965-025-04664-x","vorDoiUrl":"https://doi.org/10.1007/s10965-025-04664-x","workflowStages":[]},"version":"v1","identity":"rs-7460772","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7460772","identity":"rs-7460772","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}