Fluorescent Molecularly Imprinted Polymer Sensor Prepared Using Mesoporous Silica as Carrier for Sensitive and Accurate Detection of Bisphenol A

Fluorescent Molecularly Imprinted Polymer Sensor Prepared Using Mesoporous Silica as Carrier for Sensitive and Accurate Detection of Bisphenol A | 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 Fluorescent Molecularly Imprinted Polymer Sensor Prepared Using Mesoporous Silica as Carrier for Sensitive and Accurate Detection of Bisphenol A Yanming Shao, Xuan Rong, Huanhuan Zhao, Huanran Feng, Wenli Ma, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8074508/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 17 Mar, 2026 Read the published version in Microchimica Acta → Version 1 posted 7 You are reading this latest preprint version Abstract A fluorescent molecularly imprinted polymer (FMIP) sensor for sensitive detection of bisphenol A (BPA) was constructed based on surface-initiated reversible addition fragmentation chain transfer (SI-RAFT) polymerization with mesoporous silica (mSiO 2 ) as the carrier. In this work, N-allyl-4-ethylenediamine-1, 8-naphthalimide was used as the fluorescent functional monomer and mSiO 2 as the carrier. The high specific surface area of mSiO 2 carrier providing more imprinting sites for the FMIP and thereby effectively enhances recognition efficiency of obtained imprinted polymer. Azide groups were initially grafted onto the mSiO 2 surface, and then alkynyl-functionalized RAFT agent was introduced via copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) reaction. The FMIP was synthesized by RAFT polymerization using BPA as the template, methacrylic acid (MAA) as the functional monomer. When the template BPA rebinds to the imprinting cavity, the fluorescence signal of the MIP-capped N-allyl-4-ethylenediamine-1, 8-naphthalimide can be efficiently quenched. The ratio of fluorescence intensity exhibited a linear response to the concentrations of BPA ranging from 0 to 80 µM, achieving a detection limit of 0.43 µM. Moreover, the FMIP sensor was effectively used to detect BPA in real samples, with recovery rates ranging from 96.55% to 102.25% and a relative standard deviation (RSD) of 0.4%-1.57%. The results indicate that the prepared FMIP sensor shows great potential for the detection of BPA in environmental medium. Bisphenol A Molecularly imprinted polymer Mesoporous SiO2 Fluorescent sensor RAFT polymerization Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 1. Introduction Bisphenol A (BPA) serves as a fundamental compound widely used in synthesizing polymeric materials such as polycarbonate (PC) plastics and epoxy resins. These polymer materials are extensively used in plastic products, including beverage containers, food cans and baby bottles, as well as in toys, medical devices, and electronic components[ 1 ]. The widespread utilization of BPA inevitably leads to the leakage of BPA into the surrounding environment, resulting in environmental pollution and endangering human health. BPA is widely identified as a typical endocrine-disrupting chemical (EDC), which disrupts the hormonal system in the body and may induce reproductive system lesions, cardiovascular metabolic abnormalities, and tumor risks[ 2 ]. Hence, monitoring the concentration of BPA in the environment is crucial. A variety of analytical techniques are currently available for the detection of BPA. The commonly used analytical technologies primarily include high-performance liquid chromatography (HPLC)[ 3 ], high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS)[ 4 ], gas chromatography-mass spectrometry (GC-MS)[ 5 ]and solid phase extraction (SPE)[ 6 ]. These analytical techniques face significant challenges, including intricate sample pretreatment, high instrument costs and the requirement for experienced operators, which significantly restrict their practical application. Consequently, developing a highly efficient and sensitive technique for detecting BPA in the environment is essential. The fluorescence detection has gained widespread adoption owing to its high sensitivity, simple operation, no need for complex sample pretreatment, and high efficiency. The technique has effectively been used for the sensitive detection of organic pollutants, pesticide residues, antibiotics and pharmaceutical compounds[ 7 ]. Wang et al. developed a ratiometric fluorescence sensing system utilizing carbon dots and CdTe quantum dots to detect tetrabromobisphenol A (TBBPA)[ 8 ]. Common fluorescent materials used in constructing fluorescence sensing system primarily include quantum dots, luminescent metal organic frameworks, upconversion nanoparticles and organic fluorescent dye[ 9 ]. Compared with other materials, 1, 8-naphthalimide based fluorescent molecule are superior in terms of favorable biocompatibility, high fluorescence quantum yield, excellent stability and ease of modification[ 10 ]. Due to the above advantages, 1, 8-naphthalimide based organic fluorescent dyes represent an ideal fluorescent material for synthesizing FMIP. However, fluorescence detection has the disadvantage of limited selectivity, which restricts its application. Molecularly imprinted technology (MIT) is a method for preparing of polymers with specific recognition capabilities. The prepared polymer exhibits imprint cavities that match the shape and size of the target analyte[ 11 ]. These cavities selectively recognize specific target analytes. Currently, the traditional synthesis methods for molecularly imprinted polymers (MIPs) primarily include bulk polymerization, suspension polymerization, precipitation polymerization, and emulsion polymerization. However, these traditional preparation methods entomb imprinted sites within the MIP, compromising the binding efficiency of template molecules. The core of surface molecularly imprinted polymers (SMIPs) involves constructing the imprinting cavities on the surface of solid matrix. SMIPs exhibit more accessible recognition sites, adequate selectivity and faster binding rate compared to ordinary MIPs[ 12 ]. Among various carrier materials, mesoporous silica (mSiO 2 ) has garnered significant attention due to its high specific surface area, well-defined pore structure and chemical stability, as well as excellent biocompatibility. Using mSiO 2 as the carrier will provides more imprinted sites[ 13 ]. By combining the high selectivity of SMIP with the high sensitivity of fluorescence detection, the constructed fluorescent molecularly imprinted polymer (FMIP) sensors can enable highly sensitive detection of target molecules. Free radical polymerization (FRP) is commonly used to synthesize MIPs. However, conventional FRP exhibits uncontrollable chain termination and chain transfer during the preparation of MIPs, resulting in a heterogeneous polymer structure[ 14 ]. In addition, this approach leads to heterogeneity in binding sites, reducing the selectivity of MIPs. In contrast, the controlled/living radical polymerization (CLRP) can reduce chain termination and chain transfer reactions, control polymer molecular weight, and provide a narrower molecular weight distribution. Compared with other CLRP methods, RAFT polymerization exhibits excellent controllability, broad monomer compatibility, mild reaction conditions, and facile post-modification. Based on these advantages, RAFT polymerization is well-suited for synthesizing MIPs[ 15 ]. In this work, a fluorescent molecularly imprinted polymer sensor was constructed for the sensitive detection of BPA. According to Scheme 1 , mSiO 2 was employed as the carrier material, whose high specific surface area provides sufficient recognition sites. Subsequently, alkynyl-functionalized RAFT agent was grafted onto the surface of mSiO 2 via click chemistry. Finally, FMIP was constructed via RAFT polymerization using bisphenol A as the template and N-allyl-4-ethylenediamine-1, 8-naphthalimide as the fluorescent functional monomer. Additionally, the detection conditions for FMIP were optimized, and the performance of the resulting FMIP was evaluated using fluorescence spectrophotometer. The results demonstrate that the prepared FMIP sensor provides a new approach for sensitive and accurate detection of BPA in environmental. 2. Experimental procedures 2.1. Reagents and chemicals All reagents utilized were of analytical purity. Sodium methoxide (CH 3 ONa), sublimed sulfur, ammonium nitrate (NH 4 NO 3 ) benzyl chloride (C 7 H 7 Cl), sodium methylate, potassium ferricyanide, ether, sodium hydroxide, methylbenzene, methanol, dimethyl sulfoxide (DMSO), dichloromethane, copper sulfate pentahydrate, 4-bromo-1, 8-naphthalic anhydride, hydrochloric acid (HCl), ethylene glycol monomethyl ether and allylamine hydrochloride were acquired from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). Ethyl acetate, petroleum ether, acetic acid, ethanol, cyclohexane and acetonitrile were procured from Fuyu Fine Chemical Co., Ltd. (Tianjin, China). Methacrylic acid (MAA), tetraethyl orthosilica (TEOS), 4, 4′-azobis (4-cyanovaleric acid), cetyltrimethylammonium chloride (CTAC), triethylamine (TEA), tetrabutylammonium bromide, 3-chloropropyltriethoxysilane, and sodium ascorbate were sourced from Energy Chemical Co., Ltd. (Shanghai, China), propargyl alcohol (PgOH, 99%), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), ammonium hydroxide (NH 3 ·H 2 O), 2, 2'-Azobis(2-methylpropionitrile) (AIBN), ethane-1, 2-diyl bis(2-methylprop-2-enoate) (EGDMA), 4-dimethylaminopyridine (DMAP) and triethylamine (C 6 H 15 N) were procured from Shanghai Macklin Biochemical Co., Ltd (shanghai, Chain). Allylamine hydrochloride (C 3 H 7 N·HCl), tetrabromobisphenol A (TBBPA), and bisphenol A (BPA), phenol (PhOH), and hydroquinone (HQ) were obtained from Aladdin Co. Ltd. Water used in the experiments was ultrapure deionized water. AIBN was purified by recrystallization from methanol. MAA and EGDMA underwent purification via vacuum distillation. 2.2. Apparatus The 1 H nuclear magnetic resonance (NMR) spectrum was obtained on a Bruker AV 400 MHz spectrometer (Bruker, GER). The morphology of the samples were observed using transmission electron microscopy (TEM) (FEI, USA). The FTIR spectra were acquired using an INVENIO FT-IR spectrometer (Bruker, GER) across the 4000-400 cm -1 range. The fluorescence spectrum was obtained via a fluorescence spectrophotometer (Hitachi, Japan). XPS spectra was collected using a 300 W Al-Kα radiation on an ESCALab220i-XL electron spectrometer (VG Scientific, UK). The ultraviolet absorption spectrum was collected using an ultraviolet-visible (UV-Vis) spectrophotometer (Purkinje, China). 2.3. Synthesis of SiO 2 @mSiO 2 SiO 2 was prepared using the Stöber method[16]. Initially, ethanol (30 mL) and deionized water (50 mL) were mixed, then 12 mL of NH 3 ·H 2 O was introduced with continuous stirring for 30 min. Then, 25 mL of TEOS in ethanol (1:4, v/v) was dropwise added into the above solution. The reaction system was maintained under constant stirring for 12 h. The resulting SiO 2 was obtained via centrifugation, ethanol-washed, and vacuum-dried at 60°C. 21.6 g of CTAC and 0.45 g of SiO 2 were introduced into 135 mL of deionized water and subjected to ultrasonic treatment. Then, 205 μL of TEA was introduced into the mixture, which was then proceeded at 50°C for 3 h. A mixed solution of 27 mL of cyclohexane and 2.7 mL of TEOS was gradually introduced to the preceding mixture and reacted for 14 h at 60°C. The products are washed with deionized water and ethanol. Subsequently, the obtained particles were dispersed in an ethanol solution containing ammonium nitrate and refluxed at 65°C for 12 h. Ultimately, the SiO 2 @mSiO 2 was obtained by washing the products repeatedly with ethanol, followed by centrifugation and vacuum-drying at 60°C. 2.4. Synthesis of SiO 2 @mSiO 2 -N 3 2.93 g of sodium azide was dissolved in 112 mL of anhydrous acetonitrile. After full dissolution, 1.94 g of tetrabutylammonium bromide and 7.23 mL of 3-chloropropyltriethoxysilane were introduced. The reaction proceeded at 75°C for 48 h within a N 2 environment. The crude product was washed using anhydrous diethyl ether and filtered. Finally, 3-azidopropyltriethoxysilane was obtained after rotary evaporation[17]. 0.2 g of SiO 2 @mSiO 2 was dispersed in 160 mL of anhydrous toluene and ultrasonicated for 40 min. Then, 2 mL of 3-azidopropyltriethoxysilane was introduced into the mixture and reacted at 70°C for 14 h within a N 2 environment. The product was obtained via centrifugation, ethanol-washed, and vacuum-dried at 50°C, yielding the azide-functionalized mesoporous carrier SiO 2 @mSiO 2 -N 3 . 2.5. Synthesis of (propargyl 4-cyanopentanate) dithiobenzoate The processes of synthesis of (propargyl 4-cyanopentanate) dithiobenzoate (PCPADB) is shown in Fig. S1. 21.6 g of sodium methoxide and 12.8 g of sublimated sulfur were dissolved in 150 mL methanol in a N 2 environment. Then 22.9 g of benzyl chloride was introduced dropwise into the mixture, which was then maintained at 35°C for 10 h. The products were extracted with 0.1 M HCl, followed by deionized water and 1 M NaOH to obtain a solution of sodium dithiobenzoate. 13.17 g of potassium ferricyanide was dissolved in 180 mL of water. The resulting potassium ferricyanide solution was gradually introduced into the solution of sodium dithiobenzoate under vigorous stirring for 8 h in the dark. Upon completion, the dithiobenzoic acid dimer was obtained after washing and vacuum drying. 4.66 g of dithiobenzoic acid dimer and 6.40 g of 4, 4′-azobis (4-cyanovaleric acid) were dissolved in 80 mL of anhydrous ethyl acetate. The reaction was sustained at 70°C for 18 h within a N 2 environment. The crude product was subjected to purification through column chromatography with an ethyl acetate/petroleum ether ratio of 3/7 and was subsequently desolvated under reduced pressure to afford (4-cyanopentanoic acid) dithiobenzoate (CPADB). 0.7 g of CPADB, 0.479 mL of propargyl alcohol, 1.375 g of EDC and 0.0875 g of DMAP were introduced into 20 mL anhydrous dichloromethane. The reaction was sustained at room temperature for 18 h. The product was extracted with HCl and water. Ultimately, PCPADB was obtained through column chromatography purification (ethyl acetate/hexane = 1/4) and rotary evaporation[18]. 2.6. Synthesis of SiO 2 @mSiO 2 -PCPADB 0.16 g of SiO 2 @mSiO 2 -N 3 was dispersed in 40 mL of DMSO, and 70 mg of PCPADB was added. Subsequently, 5.396 mg of CuSO 4 ·5H 2 O and 2.138 mg of ascorbic acid were introduced into the above dispersion. The process proceeded at 50°C for 12 h within a N 2 environment. The RAFT reagent-modified mesoporous silica SiO 2 @mSiO 2 -PCPADB was obtained through centrifugation, washed with ethanol and dried under vacuum[19]. 2.7. Synthesis of fluorescent functional monomer N-allyl-4-ethylenediamine-1, 8-naphthalimide Firstly, 1.662 g of 4-bromo-1, 8-naphthalic anhydride and 0.562 g of allylamine hydrochloride were ultrasonically dissolved in 80 mL ethanol, and then 835 μL triethylamine was introduced. The process was sustained at 80°C for 7 h within a N 2 environment. N-allyl-1, 8-naphthalimide was obtained after rotary evaporation[20]. 209.3 mg of N-allyl-1, 8-naphthalimide and 2 mL of ethylenediamine were introduced into a three-necked flask, with 20 mL of ethylene glycol monomethyl ether subsequently added. The process was sustained at 110°C for 6 h within a N 2 environment. The product was extracted with ethyl acetate. The product N-allyl-4-ethylenediamine-1, 8-naphthalimide was obtained after rotary evaporation and vacuum drying[10]. The processes of synthesis of N-allyl-4-ethylenediamine-1, 8-naphthalimide is shown in Fig. S2. 2.8. Synthesis of FMIP 86.1 mg of methacrylic acid, 10 mg of N-allyl-4-ethylenediamine-1, 8-naphthalimide and 57 mg of BPA were mixed with 30 mL anhydrous toluene with continuous stirring. Subsequently, 50 mg of SiO 2 @mSiO 2 -PCPADB material was introduced and ultrasonically stirred for 30 min. Next, 940 μL of EGDMA and 20 mg of AIBN were introduced into the above mixture and polymerized at 65°C for 24 h under N 2 . Then obtain the reaction products through washing and drying. Subsequently, the BPA was then completely extracted using Soxhlet extraction with a methanol/acetic acid mixture (9:1, v:v) for 48 h. The FMIP was obtained by vacuum drying. For comparison, the fluorescence non-imprinted polymer (FNIP) was synthesized under the identical conditions without the addition of BPA. 2.9. Fluorescence measurement An appropriate amount of FMIP was introduced into 100 mL of phosphate buffer solution (pH = 7) to prepare a working solution. Then, 2 mL of working solution was combined with varying concentrations of BPA standard solution to achieve final BPA concentrations within the range of 5 to 80 μM in the obtained mixture solutions. After that, the mixture was incubated for 12 min. Fluorescence measurements were performed using a fluorescence spectrometer with an excitation wavelength of 430 nm and an emission range of 450-700 nm. Subsequently, the fluorescence intensity at 528 nm was recorded. FNIP was treated according to the same procedure. 2.10. Selective experiments Selectivity experiments were performed to assess the specificity of the FMIP sensor. The F 0 /F values of BPA and its structural analogues, including TBBPA, PhOH, and HQ were measured under uniform experimental parameters. The selectivity performance of the sensor was determined through monitoring fluorescence intensity ratio variations. 2.11. Detection of BPA in real samples The accuracy and feasibility of the FMIP sensor were demonstrated by measuring BPA in tap water and lake water. The samples were centrifuged and filtered through 0.22 μm microporous membrane to eliminate large particulate impurities. Then, various concentrations of BPA were dispersed in water samples with the standard addition method. The spiked samples were introduced into the FMIP solution and incubated for 12 min. The fluorescence intensity of the mixture was immediately tested and recorded. Subsequently, the recovery rate and relative standard deviations (RSD) were calculated. 3. Result and discussion 3.1. Materials Characterization The 1 H NMR spectra of 3-azidopropyltriethoxysilane, (4-cyanopentanoic acid) dithiobenzoate, (propargyl 4-cyanopentanate) dithiobenzoate, N-allyl-1, 8-naphthalimide, N-allyl-4-ethylenediamine-1, 8-naphthalimide are shown in Fig. S3-S7. All these results indicated that organic compounds were successfully synthesized. TEM images were employed to observe the morphology of SiO 2 , SiO 2 @mSiO 2 and FMIP. The SiO 2 microspheres display uniform spherical morphology with an approximate diameter of 240 nm (Fig. 1a and b). After coating with a mSiO 2 layer, the particle size increased to approximately 320 nm. The porous morphology could be clearly observed (Fig. 1c and d), suggesting the successful preparation of SiO 2 @mSiO 2 . Following polymerization, the SiO 2 @mSiO 2 was wrapped by a uniform polymer layer, demonstrating the successful synthesis of FMIP (Fig. 1e and f). As seen in Fig. 2A, the structure and composition of SiO 2 , SiO 2 @mSiO 2 -N 3 , SiO 2 @mSiO 2 -PCPADB and FMIP were characterized by FTIR. The peaks at 805 cm -1 and 466 cm -1 were attributed to Si–O bending vibration and stretching vibration, respectively. While the characteristic peak at 1097 cm -1 signified stretching vibration of Si-O-Si (Fig. 2Aa)[21]. The results illustrated that SiO 2 was successfully prepared. The characteristic peak at 2105 cm -1 corresponded to the stretching vibration of the azide group (Fig. 2Ab)[22], indicating that the azide group has been successfully modified on the carrier. After click chemistry, the characteristic peak at 1207 cm -1 was marked to C=S stretching vibration in the RAFT agent (Fig. 2Ac)[23], indicating that the RAFT agent has been successfully grafted. After polymerization, the characteristic peak at 1735 cm -1 was ascribed to C=O stretching vibration in EGDMA (Fig. 2Ad)[24], which confirmed the successful preparation of FMIP. The elemental composition of the synthesized materials was determined via XPS analysis. The wide scan spectra for SiO 2 @mSiO 2 -N 3 , SiO 2 @mSiO 2 -PCPADC, and FMIP are depicted in Fig. 2B. The wide scan spectra of SiO 2 @mSiO 2 -N 3 exhibits a N 1s peak at 400 eV. According to the high-resolution spectrum of N 1s in Fig. 2C, three peaks at 404.3 eV, 400.8 eV, and 398.9 eV are attributed to -N= N + =N - , - N =N + =N - , -N=N + = N - , respectively, indicating that the azide group has been successfully attached to the carrier[25]. The S 2p peak was observed at 162 eV in the wide scan spectra of SiO 2 @mSiO 2 -PCPADC. As could be seen from Fig. 2D, the high-resolution S 2p spectrum exhibits two peaks at 162.4 eV and 163.5 eV, corresponding to C=S and C-S, respectively, indicating successful grafting of the RAFT agent[26]. For FMIP, the XPS wide scan spectra exhibits the C 1s and O 1s peaks at around 284.8 eV and 530 eV, respectively. The high-resolution C 1s spectrum in Fig. 2E displays three peaks at 284.6 eV, 285.8 eV, and 288.6 eV corresponding to C=C/C-C/C-H, C-N/C=S, and C=O, respectively[27]. The O 1s high-resolution spectrum in Fig. 2F displays two peaks at 532.2 eV and 533.2 eV are attributed to O=C/Si-O-Si and O-C, respectively[28]. The all results confirm that the imprinted polymer was successfully synthesized. Furthermore, the successful preparation of the FMIP was further confirmed by scanning transmission electron microscope (STEM) with the elemental distribution mapping (Fig. S8). 3.2. Characterization of Fluorescence properties 3.2.1 Fluorescence measurements The excitation and emission spectra of N-allyl-4-ethylenediamine-1, 8-naphthalimide and FMIP were recorded in Fig. S9. Under 430 nm excitation, the N-allyl-4-ethylenediamine-1, 8-naphthalimide displayed a strong fluorescence emission peak at 522 nm (Fig. S9a and b). After polymerization, the fluorescence emission peak of the FMIP at 528 nm under 430 nm excitation (Fig. S9c and d). 3.2.2 optimization of FMIP conditions To enhance the fluorescence detection performance of the FMIP sensor, key influencing factors such as excitation wavelength, FMIP concentration, pH and incubation time were optimized. The optimal excitation wavelength of the FMIP was determined by exciting the sample at various excitation wavelengths and recording the corresponding fluorescence intensity values. From Fig. 3A, the FMIP sensor exhibits the maximum fluorescence intensity at 528 nm under 430 nm excitation. Consequently, all subsequent measurements were performed under excitation at 430 nm. The concentration of FMIP affects the sensitivity of BPA fluorescence detection. The fluorescence quenching ratio (F 0 -F)/F 0 of FMIP within the concentration range of 0.062-1 mg/mL (where F 0 and F stands for the fluorescence intensities of the FMIP before and after combined with BPA, respectively) was studied. Fig. 3B demonstrates that the maximum (F 0 -F)/F 0 was achieved at a concentration of 0.25 mg/mL, indicating optimal binding between BPA and the imprinted cavities at this concentration. Consequently, the concentration of 0.25 mg/mL was used for all subsequent tests. The pH value during the detection process significantly influenced the recognition performance of FMIP. The (F 0 -F)/F 0 of the FMIP across a pH range of 4 to 9 was used to evaluate its recognition performance. As shown in Fig. 3C, when the pH is below 7, the (F 0 -F)/F 0 of FMIP increased gradually. At pH 7, the (F 0 -F)/F 0 reached its maximum and subsequently decreased with further increases in pH. This is primarily attributed to the protonation of the amino group in the fluorescent functional monomer under acidic conditions. This protonation prevents the template from forming effective hydrogen bonds with the fluorescent functional monomer. Under alkaline conditions, the phenolic hydroxyl group of BPA undergo deprotonation, forming negatively charged phenoxy anions. The electrostatic repulsion between the imprinted sites and phenolate anions thereby reduces the binding ability of the imprinting cavity[29]. Thus, pH 7 was selected for all fluorescence testing. Under the above conditions, the effect of incubation time on FMIP fluorescence performance was investigated. The incubation time was determined by observing changes in the fluorescence intensity ratio (F 0 /F) value. From Fig. 3D, the F 0 /F value increased gradually within 12 min, after which it stabilized. Consequently, 8 min was selected as the optimal incubation time for subsequent testing. 3.2.3 Analytical performance of FMIP Under the optimized parameters, the fluorescence response of FMIP was investigated across a range of BPA concentrations (0-80 μM). As can be seen from Fig. 4A, the fluorescence emission intensity of FMIP at 528 nm gradually decreased with increasing of BPA concentration. According to Fig. 4B, the F 0 /F of FMIP exhibits a good linear relationship with BPA concentrations between 0-80 μM, and the linear regression equation was y=0.00823x+0.99788 (R 2 =0.9983). The limit of detection (LOD) for BPA was calculated to be 0.43 μM, based on the formula LOD=3δ/s (δ is the standard deviation of the blank measurement, s is the gradient of the calibration curve). For comparison, parallel experiments were conducted using FNIP. As shown in Fig. 4C, within the range of 0 to 80 μM, the fluorescence intensity of FNIP also decreased as BPA concentration grew, but the sensitivity was significantly lower than that observed with FMIP. This difference is attributed to the absence of specific binding cavities complementary to BPA in FNIP, resulting in lower sensitivity toward the target analyte. A linear relationship was also obtained for the FNIP between the F 0 /F and the BPA concentration (Fig. 4D), following the linear regression equation y=0.00132x+1.01544 (R 2 =0.9866). 3.2.4 The selectivity and fluorescence stability of the FMIP sensor for BPA The selectivity of the FMIP sensor toward BPA was examined by studying the fluorescence intensity ratio of FMIP in the presence of BPA and its structural analogues. As shown in Fig. 5A, BPA showed the highest F 0 /F for FMIP, indicating the strongest quenching effect. In contrast, its structural analogues showed significantly lower F 0 /F values. This pronounced selectivity originates from the presence of imprinting cavities within the FMIP, which are complementary in size and shape to BPA. In contrast, the FNIP exhibit a low fluorescence emission ratio for BPA and its analog, owing to the lack of specific BPA-imprinted cavities. The above results demonstrate the excellent selectivity of the prepared FMIP for BPA. The stability of the FMIP is also a critical factor in evaluating sensor performance. The fluorescence stability of FMIP was evaluated by monitoring the fluorescence intensity under room temperature conditions and continuous UV lamp irradiation. As shown in Fig. 5B, after continuous exposure to ultraviolet light for 120 minutes, the fluorescence intensity remained virtually unchanged. Furthermore, store the FMIP solution at room temperature for 7 days. From Fig. 5C, the fluorescence intensity decreased slightly within 7 days, but the change was negligible. Collectively, experimental results indicate that the sensor exhibits excellent stability. 3.2.5 Mechanism investigation of fluorescence quenching The possible quenching mechanism of BPA on the FMIP was investigated. As shown in Fig. S10A, no overlap exists in the UV absorption spectrum of BPA (a) and the emission spectrum of N-allyl-4-ethylenediamine-1, 8-naphthalimide (b), indicating that the fluorescence resonance energy transfer (FRET) was not the cause of fluorescence quenching. Therefore, the photoinduced electron transfer (PET) is the most likely quenching mechanism. In Fig. S10B, the hydroxyl groups in BPA are capable of forming hydrogen bonds with the amino groups found in the fluorescent functional monomer. This interaction facilitates charge transfer from fluorescent functional monomer to BPA, causing fluorescence quenching. Furthermore, molecular orbital theory can also explain this phenomenon. Under ultraviolet light excitation, electrons in the valence band of fluorescent monomers were excited to the conduction band. Excited electrons subsequently revert to the valence band, thereby generating fluorescence. However, when the template BPA binds to the imprint cavity, these excited electrons at the conductive band of fluorescent functional monomer can directly transfer to the lowest unoccupied molecular orbital (LUMO) of BPA, causing fluorescence quenching (Fig. S10C). In summary, the fluorescence quenching observed in the sensor can primarily be explained by the photoinduced electron transfer (PET) process. 3.2.6 Real sample detection To evaluate the accuracy and feasibility of FMIP in detecting BPA in real water samples. The detection of BPA in lake water and tap water was demonstrated by spiked recovery experiments. As listed in Table 1, the recovery rate in real water samples ranged from 96.55% to102.25%, with an RSD between 0.4% and 1.57%. These above results have completely demonstrated that the FMIP sensor can be used for the analysis of BPA in real water samples. Table 1 The results of quantitative detection of BPA in water samples by the sensor Samples Add (μM) Found (μM) a Recovery (%) RSD (%) b 0 ND d 0 0 Tap water 20 19.3101 96.55 0.81 40 39.7656 99.41 1.18 60 58.4039 97.34 1.57 0 ND d 0 0 Lake water c 20 20.4507 102.25 0.95 40 39.4777 98.69 1.27 60 59.4911 99.15 0.4 a Average of three measurements. b relative standard deviation. c from Keda lake in Shanxi, China. d ND: not detection. 3.2.7 Method performance comparison The performance of the fluorescence sensor prepared in this study was compared with other reported sensors (Table 2). While the detection limit of the proposed FMIP sensor is slightly higher than reported in certain existing fluorescent methods for BPA detection, it exhibits excellent selectivity. Furthermore, from a methodological perspective, this work offers a novel approach for BPA detection and demonstrates significant potential for the future detection of low-concentration target analytes. Table 2 Performance comparison of fluorescent methods for detecting BPA Methods System Linear range(μM) LOD(μM) References Fluorescence SiO 2 @CdTe@MIP 1-100 0.4 [30] Fluorescence HPTS/Smart phones 0-88 4.4 [31] Fluorescence SiO 2 @AuNCs-MIP 0-13.1 0.1 [32] Fluorescence Si NPs/HRP/H 2 O 2 0-100 0.69 [33] Fluorescence GQDs-SBA-15/MIP 0.5-20 0.18 [34] Fluorescence EGMP/MIP 5-250 5 [35] Fluorescence FMIP 0-80 0.43 This work 4. Conclusion FMIP sensor was successfully constructed to detect BPA selectively and sensitively by integrating the specific molecular recognition of MIP with the high sensitivity of fluorescence analysis. The mSiO 2 possesses a high specific surface area, making it suitable to be used as the carrier that can provide more imprinting sites. RAFT agent was grafted onto the mSiO 2 surface via click chemistry. Subsequently, FMIP was synthesized via RAFT polymerization in the presence of fluorescent functional monomers. Experimental results indicate that the fluorescence intensity ratio of FMIP exhibits a good linear relationship with BPA concentration across the 0-80 μM range, achieving a limit of detection at 0.43 μM. Moreover, the FMIP sensor performed effectively in the analysis of BPA in real water samples, achieving recoveries between 96.55% to 102.25%, with RSD ranging from 0.4% to 1.57%. In summary, the FMIP sensor exhibits specific recognition capability for BPA and provides a reliable method for the detection of this target analyte. Declarations CRediT authorship contribution statement Yanming Shao: Writing - review & editing, Supervision, Project administration, Funding acquisition. Xuan Rong: Writing - original draft, Methodology, Investigation, Conceptualization. Huanhuan Zhao: Software, Methodology, Formal analysis, Data curation. Huanran Feng: Writing - review & editing. Wenli Ma: Validation, Visualization. Wenli Peng: Software, Validation. Guohao Gao: Formal analysis, Data curation. Xianyu Yang: Investigation, Data curation. Ziwei Jiao: Data curation. Declaration of interest statement The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Acknowledgements This work was supported by the National Natural Science Foundation of China (Program No. 21806097, 22005234), the Natural Science Basic Research Plan in Shaanxi Province of China (2024JC-YBMS-109, 2025JC-YBQN-588), the Scientific Research Program Funded by Shaanxi Provincial Education Department (Program No. 18JK0104), and Research Starting Foundation of Shaanxi University of Science and Technology (Program No. 2016BJ-80). Appendix A. 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Analytical and Bioanalytical Chemistry 416: 7121-7129. https://doi.org/10.1007/s00216-024-05616-y Scheme Scheme 1 is available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Supportinginformation.docx floatimage1.png Scheme 1 Diagram illustration of the preparation of FMIP sensor Cite Share Download PDF Status: Published Journal Publication published 17 Mar, 2026 Read the published version in Microchimica Acta → Version 1 posted Editorial decision: Revision requested 05 Jan, 2026 Reviews received at journal 20 Dec, 2025 Reviewers agreed at journal 05 Dec, 2025 Reviewers invited by journal 03 Dec, 2025 Editor assigned by journal 13 Nov, 2025 Submission checks completed at journal 12 Nov, 2025 First submitted to journal 10 Nov, 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. 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1","display":"","copyAsset":false,"role":"figure","size":888228,"visible":true,"origin":"","legend":"\u003cp\u003eTEM images of SiO\u003csub\u003e2\u003c/sub\u003e (a, b), SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e (c, d) and FMIP (e, f)\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-8074508/v1/38eb09c668b4436b0b67ce9b.png"},{"id":97504649,"identity":"b24f9f34-d858-49cd-bc62-c6cd8e103326","added_by":"auto","created_at":"2025-12-05 07:34:35","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":614614,"visible":true,"origin":"","legend":"\u003cp\u003eFT-IR spectra of SiO\u003csub\u003e2\u003c/sub\u003e A(a), SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-N\u003csub\u003e3\u003c/sub\u003e A(b), SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-PCPADB A(c) and FMIP A(d). XPS wide scan spectrum spectra of SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-N\u003csub\u003e3\u003c/sub\u003e, SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-PCPADC, FMIP (B). High-resolution N 1s spectra of SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-N\u003csub\u003e3\u003c/sub\u003e (C), S 2p spectra of SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-PCPADC (D), C 1s and O 1s spectra of FMIP (E, F)\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-8074508/v1/fa85613400be9262485b8884.png"},{"id":97671444,"identity":"517fb869-28d0-4c33-92df-12c4fa3ba7cb","added_by":"auto","created_at":"2025-12-08 09:32:37","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":269464,"visible":true,"origin":"","legend":"\u003cp\u003eThe fluorescence emission spectrum of FMIP at different excitation wavelengths (A), the impact of FMIP concentration (B) on the fluorescence quenching ratio of the system, the impact of pH (C) on the fluorescence quenching ratio of the FMIP system, and the impact of incubation time on the fluorescence intensity ratio (D)\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-8074508/v1/880352a0bbd781d0d999cb1b.png"},{"id":97669820,"identity":"f10a4f49-8499-4edf-bb1d-87d652649fbd","added_by":"auto","created_at":"2025-12-08 09:29:00","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":255058,"visible":true,"origin":"","legend":"\u003cp\u003eFluorescence spectra of FMIP (A) and FNIP (C). The linear relationship between the F\u003csub\u003e0\u003c/sub\u003e/F of FMIP (B) and FNIP (D) and different concentrations of BPA\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-8074508/v1/7b067fc6a4fac9d2fe406d73.png"},{"id":97670355,"identity":"2570035a-39b8-4553-9505-7a71030cbbf6","added_by":"auto","created_at":"2025-12-08 09:30:25","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":229644,"visible":true,"origin":"","legend":"\u003cp\u003eThe selectivity of FMIP for the detection of BPA (A), fluorescent stability of FMIP in UV lamp (B) and room temperature (C)\u003c/p\u003e","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-8074508/v1/d3ff3f71e4d7997d1b4b7601.png"},{"id":105223332,"identity":"b4e66053-cb81-41b2-bec1-21e8b18e81ba","added_by":"auto","created_at":"2026-03-23 16:04:03","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2918020,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8074508/v1/0818ebe1-eea0-427e-9413-b1a32935d448.pdf"},{"id":97504654,"identity":"2f2a5f08-45f8-4c2c-851a-54f0dfb7c698","added_by":"auto","created_at":"2025-12-05 07:34:35","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":1852544,"visible":true,"origin":"","legend":"","description":"","filename":"Supportinginformation.docx","url":"https://assets-eu.researchsquare.com/files/rs-8074508/v1/e1172db97d435781a0186389.docx"},{"id":97504651,"identity":"71ef48dc-bea0-4d6e-a541-46966a10bdd0","added_by":"auto","created_at":"2025-12-05 07:34:35","extension":"png","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":646218,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eScheme 1\u003c/strong\u003e Diagram illustration of the preparation of FMIP sensor\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8074508/v1/94d9c270a19dd3c9841343f7.png"}],"financialInterests":"No competing interests reported.","formattedTitle":"Fluorescent Molecularly Imprinted Polymer Sensor Prepared Using Mesoporous Silica as Carrier for Sensitive and Accurate Detection of Bisphenol A","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eBisphenol A (BPA) serves as a fundamental compound widely used in synthesizing polymeric materials such as polycarbonate (PC) plastics and epoxy resins. These polymer materials are extensively used in plastic products, including beverage containers, food cans and baby bottles, as well as in toys, medical devices, and electronic components[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. The widespread utilization of BPA inevitably leads to the leakage of BPA into the surrounding environment, resulting in environmental pollution and endangering human health. BPA is widely identified as a typical endocrine-disrupting chemical (EDC), which disrupts the hormonal system in the body and may induce reproductive system lesions, cardiovascular metabolic abnormalities, and tumor risks[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Hence, monitoring the concentration of BPA in the environment is crucial.\u003c/p\u003e\u003cp\u003eA variety of analytical techniques are currently available for the detection of BPA. The commonly used analytical technologies primarily include high-performance liquid chromatography (HPLC)[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS)[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], gas chromatography-mass spectrometry (GC-MS)[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]and solid phase extraction (SPE)[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. These analytical techniques face significant challenges, including intricate sample pretreatment, high instrument costs and the requirement for experienced operators, which significantly restrict their practical application. Consequently, developing a highly efficient and sensitive technique for detecting BPA in the environment is essential.\u003c/p\u003e\u003cp\u003eThe fluorescence detection has gained widespread adoption owing to its high sensitivity, simple operation, no need for complex sample pretreatment, and high efficiency. The technique has effectively been used for the sensitive detection of organic pollutants, pesticide residues, antibiotics and pharmaceutical compounds[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Wang et al. developed a ratiometric fluorescence sensing system utilizing carbon dots and CdTe quantum dots to detect tetrabromobisphenol A (TBBPA)[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Common fluorescent materials used in constructing fluorescence sensing system primarily include quantum dots, luminescent metal organic frameworks, upconversion nanoparticles and organic fluorescent dye[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Compared with other materials, 1, 8-naphthalimide based fluorescent molecule are superior in terms of favorable biocompatibility, high fluorescence quantum yield, excellent stability and ease of modification[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Due to the above advantages, 1, 8-naphthalimide based organic fluorescent dyes represent an ideal fluorescent material for synthesizing FMIP. However, fluorescence detection has the disadvantage of limited selectivity, which restricts its application.\u003c/p\u003e\u003cp\u003eMolecularly imprinted technology (MIT) is a method for preparing of polymers with specific recognition capabilities. The prepared polymer exhibits imprint cavities that match the shape and size of the target analyte[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. These cavities selectively recognize specific target analytes. Currently, the traditional synthesis methods for molecularly imprinted polymers (MIPs) primarily include bulk polymerization, suspension polymerization, precipitation polymerization, and emulsion polymerization. However, these traditional preparation methods entomb imprinted sites within the MIP, compromising the binding efficiency of template molecules. The core of surface molecularly imprinted polymers (SMIPs) involves constructing the imprinting cavities on the surface of solid matrix. SMIPs exhibit more accessible recognition sites, adequate selectivity and faster binding rate compared to ordinary MIPs[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Among various carrier materials, mesoporous silica (mSiO\u003csub\u003e2\u003c/sub\u003e) has garnered significant attention due to its high specific surface area, well-defined pore structure and chemical stability, as well as excellent biocompatibility. Using mSiO\u003csub\u003e2\u003c/sub\u003e as the carrier will provides more imprinted sites[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. By combining the high selectivity of SMIP with the high sensitivity of fluorescence detection, the constructed fluorescent molecularly imprinted polymer (FMIP) sensors can enable highly sensitive detection of target molecules.\u003c/p\u003e\u003cp\u003eFree radical polymerization (FRP) is commonly used to synthesize MIPs. However, conventional FRP exhibits uncontrollable chain termination and chain transfer during the preparation of MIPs, resulting in a heterogeneous polymer structure[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. In addition, this approach leads to heterogeneity in binding sites, reducing the selectivity of MIPs. In contrast, the controlled/living radical polymerization (CLRP) can reduce chain termination and chain transfer reactions, control polymer molecular weight, and provide a narrower molecular weight distribution. Compared with other CLRP methods, RAFT polymerization exhibits excellent controllability, broad monomer compatibility, mild reaction conditions, and facile post-modification. Based on these advantages, RAFT polymerization is well-suited for synthesizing MIPs[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn this work, a fluorescent molecularly imprinted polymer sensor was constructed for the sensitive detection of BPA. According to Scheme \u003cspan refid=\"Sch1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, mSiO\u003csub\u003e2\u003c/sub\u003e was employed as the carrier material, whose high specific surface area provides sufficient recognition sites. Subsequently, alkynyl-functionalized RAFT agent was grafted onto the surface of mSiO\u003csub\u003e2\u003c/sub\u003e via click chemistry. Finally, FMIP was constructed via RAFT polymerization using bisphenol A as the template and N-allyl-4-ethylenediamine-1, 8-naphthalimide as the fluorescent functional monomer. Additionally, the detection conditions for FMIP were optimized, and the performance of the resulting FMIP was evaluated using fluorescence spectrophotometer. The results demonstrate that the prepared FMIP sensor provides a new approach for sensitive and accurate detection of BPA in environmental.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"2. Experimental procedures","content":"\u003cp\u003e\u003cstrong\u003e2.1. Reagents and chemicals\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll reagents utilized were of analytical purity. Sodium methoxide (CH\u003csub\u003e3\u003c/sub\u003eONa), sublimed sulfur,\u0026nbsp;ammonium nitrate (NH\u003csub\u003e4\u003c/sub\u003eNO\u003csub\u003e3\u003c/sub\u003e)\u0026nbsp;benzyl chloride (C\u003csub\u003e7\u003c/sub\u003eH\u003csub\u003e7\u003c/sub\u003eCl), sodium methylate,\u0026nbsp;potassium ferricyanide, ether, sodium hydroxide, methylbenzene, methanol, dimethyl sulfoxide (DMSO), dichloromethane, copper sulfate pentahydrate, 4-bromo-1, 8-naphthalic anhydride,\u0026nbsp;hydrochloric acid (HCl), ethylene glycol monomethyl ether\u0026nbsp;and\u0026nbsp;allylamine hydrochloride were acquired from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). Ethyl acetate, petroleum ether, acetic acid, ethanol, cyclohexane and acetonitrile were procured from Fuyu Fine Chemical Co., Ltd. (Tianjin, China). Methacrylic acid (MAA), tetraethyl orthosilica (TEOS), 4, 4\u0026prime;-azobis (4-cyanovaleric acid), cetyltrimethylammonium chloride (CTAC), triethylamine (TEA), tetrabutylammonium bromide, 3-chloropropyltriethoxysilane, and sodium ascorbate were sourced from Energy Chemical Co., Ltd. (Shanghai, China), propargyl alcohol (PgOH, 99%),\u003cem\u003e\u0026nbsp;\u003c/em\u003e1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), ammonium hydroxide (NH\u003csub\u003e3\u003c/sub\u003e\u0026middot;H\u003csub\u003e2\u003c/sub\u003eO), 2, 2\u0026apos;-Azobis(2-methylpropionitrile) (AIBN), ethane-1, 2-diyl bis(2-methylprop-2-enoate) (EGDMA), 4-dimethylaminopyridine (DMAP) and triethylamine (C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e15\u003c/sub\u003eN) were procured from Shanghai Macklin Biochemical Co., Ltd (shanghai, Chain). Allylamine hydrochloride (C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e7\u003c/sub\u003eN\u0026middot;HCl), tetrabromobisphenol A (TBBPA), and bisphenol A (BPA), phenol (PhOH), and hydroquinone (HQ) were obtained from Aladdin Co. Ltd. Water used in the experiments was ultrapure deionized water.\u0026nbsp;AIBN was purified by recrystallization from methanol. MAA and EGDMA underwent purification via vacuum distillation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.2.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eApparatus\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe \u003csup\u003e1\u003c/sup\u003eH nuclear magnetic resonance (NMR) spectrum was obtained on a Bruker AV 400 MHz spectrometer (Bruker, GER). The morphology of the samples were observed using transmission electron microscopy (TEM) (FEI, USA). The FTIR spectra were acquired using an INVENIO FT-IR spectrometer (Bruker, GER) across the 4000-400 cm\u003csup\u003e-1\u003c/sup\u003e range. The fluorescence spectrum was obtained via a fluorescence spectrophotometer (Hitachi, Japan).\u0026nbsp;XPS spectra was collected using a 300 W Al-K\u0026alpha; radiation on an ESCALab220i-XL electron spectrometer (VG Scientific, UK).\u0026nbsp;The ultraviolet absorption spectrum was collected using an ultraviolet-visible (UV-Vis) spectrophotometer (Purkinje, China).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.3. Synthesis of\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eSiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e was prepared using the St\u0026ouml;ber method[16]. Initially, ethanol (30 mL) and deionized water (50 mL) were mixed, then 12 mL of NH\u003csub\u003e3\u003c/sub\u003e\u0026middot;H\u003csub\u003e2\u003c/sub\u003eO was introduced with continuous stirring for 30 min. Then, 25 mL of TEOS in ethanol (1:4, v/v) was dropwise added into the above solution. The reaction system was maintained under constant stirring for 12 h. The resulting SiO\u003csub\u003e2\u003c/sub\u003e was obtained via centrifugation, ethanol-washed, and vacuum-dried at 60\u0026deg;C.\u003c/p\u003e\n\u003cp\u003e21.6 g of CTAC and 0.45 g of SiO\u003csub\u003e2\u003c/sub\u003e were introduced into 135 mL of deionized water and subjected to ultrasonic treatment. Then, 205 \u0026mu;L of TEA was introduced into the mixture, which was then proceeded at 50\u0026deg;C for 3 h. A mixed solution of 27 mL of cyclohexane and 2.7 mL of TEOS was gradually introduced to the preceding mixture and reacted for 14 h at 60\u0026deg;C. The products are washed with deionized water and ethanol. Subsequently, the obtained particles were dispersed in an ethanol solution containing ammonium nitrate and refluxed at 65\u0026deg;C for 12 h. Ultimately, the SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e was obtained by washing the products repeatedly with ethanol, followed by centrifugation and vacuum-drying at 60\u0026deg;C.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.4. Synthesis of SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-N\u003csub\u003e3\u003c/sub\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e2.93 g of sodium azide was dissolved in 112 mL of anhydrous acetonitrile. After full dissolution, 1.94 g of\u0026nbsp;tetrabutylammonium bromide and 7.23 mL of 3-chloropropyltriethoxysilane were introduced. The reaction proceeded at 75\u0026deg;C for 48 h within a N\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eenvironment. The crude product was washed using anhydrous diethyl ether and filtered. Finally, 3-azidopropyltriethoxysilane was obtained after rotary evaporation[17].\u003c/p\u003e\n\u003cp\u003e0.2 g of SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e was dispersed in 160 mL of anhydrous toluene and ultrasonicated for 40 min. Then, 2 mL of 3-azidopropyltriethoxysilane was introduced into the mixture and reacted at 70\u0026deg;C for 14 h within a N\u003csub\u003e2\u003c/sub\u003e environment. The product was obtained via centrifugation, ethanol-washed, and vacuum-dried at 50\u0026deg;C, yielding the azide-functionalized mesoporous carrier SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-N\u003csub\u003e3\u003c/sub\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.5. Synthesis of (propargyl 4-cyanopentanate) dithiobenzoate\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe\u0026nbsp;processes of synthesis of\u0026nbsp;(propargyl 4-cyanopentanate) dithiobenzoate (PCPADB) is shown in\u0026nbsp;Fig.\u0026nbsp;S1. 21.6 g of sodium methoxide and 12.8 g of sublimated sulfur were dissolved in 150 mL methanol in a N\u003csub\u003e2\u003c/sub\u003e environment. Then 22.9 g of benzyl chloride was introduced dropwise into the mixture, which was then maintained at 35\u0026deg;C for 10 h. The products were extracted with 0.1 M HCl, followed by deionized water and 1 M NaOH to obtain a solution of sodium dithiobenzoate.\u003c/p\u003e\n\u003cp\u003e13.17 g of potassium ferricyanide was dissolved in 180 mL of water. The resulting potassium ferricyanide solution was gradually introduced into the solution of sodium dithiobenzoate under vigorous stirring for 8 h in the dark. Upon completion, the dithiobenzoic acid dimer was obtained after washing and vacuum drying.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e4.66 g of dithiobenzoic acid dimer and 6.40 g of 4, 4\u0026prime;-azobis (4-cyanovaleric acid) were dissolved in 80 mL of anhydrous ethyl acetate. The reaction was sustained at 70\u0026deg;C for 18 h within a N\u003csub\u003e2\u003c/sub\u003e environment. The crude product was subjected to purification through column chromatography with an ethyl acetate/petroleum ether ratio of 3/7 and was subsequently desolvated under reduced pressure to afford (4-cyanopentanoic acid) dithiobenzoate (CPADB).\u003c/p\u003e\n\u003cp\u003e0.7 g of CPADB, 0.479 mL of propargyl alcohol, 1.375 g of EDC and 0.0875 g of DMAP were introduced into 20 mL anhydrous dichloromethane. The reaction was sustained at room temperature for 18 h. The product was extracted with HCl and water. Ultimately, PCPADB was obtained through column chromatography purification (ethyl acetate/hexane = 1/4) and rotary evaporation[18].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.6. Synthesis of SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-PCPADB\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e0.16 g of SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-N\u003csub\u003e3\u003c/sub\u003e was dispersed in 40 mL of DMSO, and 70 mg of PCPADB was added. Subsequently, 5.396 mg of CuSO\u003csub\u003e4\u003c/sub\u003e\u0026middot;5H\u003csub\u003e2\u003c/sub\u003eO and 2.138 mg of ascorbic acid were introduced into the above dispersion. The process proceeded at 50\u0026deg;C for 12 h within a N\u003csub\u003e2\u003c/sub\u003e environment. The RAFT reagent-modified mesoporous silica SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-PCPADB was obtained through centrifugation, washed with ethanol and dried under vacuum[19].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.7. Synthesis of fluorescent\u003c/strong\u003e \u003cstrong\u003efunctional monomer N-allyl-4-ethylenediamine-1, 8-naphthalimide\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFirstly, 1.662 g of 4-bromo-1, 8-naphthalic anhydride and 0.562 g of allylamine hydrochloride were ultrasonically dissolved in 80 mL ethanol, and then 835 \u0026mu;L triethylamine was introduced. The process was sustained at 80\u0026deg;C for 7 h within a N\u003csub\u003e2\u003c/sub\u003e environment. N-allyl-1, 8-naphthalimide was obtained after rotary evaporation[20].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e209.3 mg of N-allyl-1, 8-naphthalimide and 2 mL of ethylenediamine were introduced into a three-necked flask, with 20 mL of ethylene glycol monomethyl ether subsequently added. The process was sustained at 110\u0026deg;C for 6 h within a N\u003csub\u003e2\u003c/sub\u003e environment. The product was extracted with ethyl acetate. The product N-allyl-4-ethylenediamine-1, 8-naphthalimide was obtained after rotary evaporation and vacuum drying[10]. The\u0026nbsp;processes of\u0026nbsp;synthesis of\u0026nbsp;N-allyl-4-ethylenediamine-1, 8-naphthalimide is shown in\u0026nbsp;Fig.\u0026nbsp;S2.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.8. Synthesis of FMIP\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e86.1 mg of methacrylic acid, 10 mg of N-allyl-4-ethylenediamine-1, 8-naphthalimide and 57 mg of BPA were mixed with 30 mL anhydrous toluene with continuous stirring. Subsequently, 50 mg of SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-PCPADB material was introduced and ultrasonically stirred for 30 min. Next, 940 \u0026mu;L of EGDMA and 20 mg of AIBN were introduced into the above mixture and polymerized at 65\u0026deg;C for 24 h under N\u003csub\u003e2\u003c/sub\u003e. Then obtain the reaction products through washing and drying. Subsequently, the BPA was then completely extracted using Soxhlet extraction with a methanol/acetic acid mixture (9:1, v:v) for 48 h. The FMIP was obtained by vacuum drying. For comparison, the fluorescence non-imprinted polymer (FNIP) was synthesized under the identical conditions without the addition of BPA.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.9. Fluorescence measurement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAn appropriate amount of FMIP was introduced into 100 mL of phosphate buffer solution (pH = 7) to prepare a working solution. Then, 2 mL of working solution was combined with varying concentrations of BPA standard solution to achieve final BPA concentrations within the range of 5 to 80 \u0026mu;M in the obtained mixture solutions.\u0026nbsp;After that, the mixture was incubated for 12 min. Fluorescence measurements were performed using a fluorescence spectrometer with an excitation wavelength of 430 nm and an emission\u0026nbsp;range of 450-700 nm. Subsequently, the fluorescence intensity at 528 nm was recorded.\u0026nbsp;FNIP was treated according to the same procedure.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.10. Selective experiments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSelectivity experiments were performed to assess the specificity of the FMIP sensor. The F\u003csub\u003e0\u003c/sub\u003e/F values of BPA and its structural analogues, including TBBPA, PhOH, and HQ were measured under uniform experimental parameters. The selectivity performance of the sensor was determined through monitoring fluorescence intensity ratio variations.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.11. Detection of BPA in real samples\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe accuracy and feasibility of the FMIP sensor were demonstrated by measuring BPA in tap water and lake water. The samples were centrifuged and filtered through 0.22 \u0026mu;m microporous membrane to eliminate large particulate impurities. Then, various concentrations of BPA were dispersed in water samples with the standard addition method. The spiked samples were introduced into the FMIP solution and incubated for 12 min. The fluorescence intensity of the mixture was immediately tested and recorded. Subsequently, the recovery rate and relative standard deviations (RSD) were calculated.\u003c/p\u003e"},{"header":"3. Result and discussion","content":"\u003cp\u003e\u003cstrong\u003e3.1.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eMaterials\u003cem\u003e\u0026nbsp;\u003c/em\u003eCharacterization\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe \u003csup\u003e1\u003c/sup\u003eH NMR spectra of 3-azidopropyltriethoxysilane, (4-cyanopentanoic acid) dithiobenzoate, (propargyl 4-cyanopentanate) dithiobenzoate, N-allyl-1, 8-naphthalimide, N-allyl-4-ethylenediamine-1, 8-naphthalimide are shown in Fig. S3-S7. All these results indicated that organic compounds were successfully synthesized.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTEM images were employed to observe the morphology of SiO\u003csub\u003e2\u003c/sub\u003e, SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eand FMIP. The SiO\u003csub\u003e2\u003c/sub\u003e microspheres display uniform spherical morphology with an approximate diameter of 240 nm (Fig. 1a and b). After coating with a mSiO\u003csub\u003e2\u003c/sub\u003e layer, the particle size increased to approximately 320 nm. The porous morphology could be clearly observed (Fig. 1c and d), suggesting the successful preparation of SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e. Following polymerization, the SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e was wrapped by a uniform polymer layer, demonstrating the successful synthesis of FMIP (Fig. 1e and f).\u003c/p\u003e\n\u003cp\u003eAs seen in Fig. 2A, the structure and composition of SiO\u003csub\u003e2\u003c/sub\u003e, SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-N\u003csub\u003e3\u003c/sub\u003e, SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-PCPADB and FMIP were characterized by FTIR. The peaks at 805 cm\u003csup\u003e-1\u003c/sup\u003e and 466 cm\u003csup\u003e-1\u003c/sup\u003e were attributed to Si\u0026ndash;O bending vibration and stretching vibration, respectively. While the characteristic peak at 1097 cm\u003csup\u003e-1\u003c/sup\u003e signified stretching vibration of Si-O-Si (Fig. 2Aa)[21]. The results illustrated that SiO\u003csub\u003e2\u003c/sub\u003e was successfully prepared. The characteristic peak at 2105 cm\u003csup\u003e-1\u003c/sup\u003e corresponded to the stretching vibration of the azide group (Fig. 2Ab)[22], indicating that the azide group has been successfully modified on the carrier. After click chemistry, the characteristic peak at 1207 cm\u003csup\u003e-1\u003c/sup\u003e was marked to C=S stretching vibration in the RAFT agent (Fig. 2Ac)[23], indicating that the RAFT agent has been successfully grafted. After polymerization, the characteristic peak at 1735 cm\u003csup\u003e-1\u003c/sup\u003e was ascribed to C=O stretching vibration in EGDMA (Fig. 2Ad)[24], which confirmed the successful preparation of FMIP.\u003c/p\u003e\n\u003cp\u003eThe elemental composition of the synthesized materials was determined via XPS analysis. The wide scan spectra for SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-N\u003csub\u003e3\u003c/sub\u003e, SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-PCPADC, and FMIP are depicted in Fig. 2B. The wide scan spectra of SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-N\u003csub\u003e3\u003c/sub\u003e exhibits a N 1s peak at 400 eV. According to the high-resolution spectrum of N 1s in Fig. 2C, three peaks at 404.3 eV, 400.8 eV, and 398.9 eV are attributed to -N=\u003cu\u003eN\u003c/u\u003e\u003csup\u003e+\u003c/sup\u003e=N\u003csup\u003e-\u003c/sup\u003e, -\u003cu\u003eN\u003c/u\u003e=N\u003csup\u003e+\u003c/sup\u003e=N\u003csup\u003e-\u003c/sup\u003e, -N=N\u003csup\u003e+\u003c/sup\u003e=\u003cu\u003eN\u003c/u\u003e\u003csup\u003e-\u003c/sup\u003e, respectively, indicating that the azide group has been successfully attached to the carrier[25]. The S 2p peak was observed at 162 eV in the wide scan spectra of SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-PCPADC. As could be seen from Fig. 2D, the high-resolution S 2p spectrum exhibits two peaks at 162.4 eV and 163.5 eV, corresponding to C=S and C-S, respectively, indicating successful grafting of the RAFT agent[26]. For FMIP, the XPS wide scan spectra exhibits the C 1s and O 1s peaks at around 284.8 eV and 530 eV, respectively. The high-resolution C 1s spectrum in Fig. 2E displays three peaks at 284.6 eV, 285.8 eV, and 288.6 eV corresponding to C=C/C-C/C-H, C-N/C=S, and C=O, respectively[27]. The O 1s high-resolution spectrum in Fig. 2F displays two peaks at 532.2 eV and 533.2 eV are attributed to O=C/Si-O-Si and O-C, respectively[28]. The all results confirm that the imprinted polymer was successfully synthesized. Furthermore, the successful preparation of the FMIP was further confirmed by scanning transmission electron microscope (STEM) with the elemental distribution mapping (Fig. S8).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2. Characterization of Fluorescence properties\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2.1 Fluorescence measurements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe excitation and emission spectra of N-allyl-4-ethylenediamine-1, 8-naphthalimide and FMIP were recorded in\u0026nbsp;Fig.\u0026nbsp;S9. Under 430 nm excitation, the N-allyl-4-ethylenediamine-1, 8-naphthalimide displayed a strong fluorescence emission peak at 522 nm (Fig.\u0026nbsp;S9a and b). After polymerization, the fluorescence emission peak of the FMIP at 528 nm under 430\u0026thinsp;nm excitation (Fig.\u0026nbsp;S9c and d).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2.2 optimization of FMIP conditions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo enhance the fluorescence detection performance of the FMIP sensor, key influencing factors such as excitation wavelength, FMIP concentration, pH and incubation time were optimized. The optimal excitation wavelength of the FMIP was determined by exciting the sample at various excitation wavelengths and recording the corresponding fluorescence intensity values. From Fig. 3A, the FMIP sensor exhibits the maximum fluorescence intensity at 528 nm under 430 nm excitation. Consequently, all subsequent measurements were performed under excitation at 430 nm.\u003c/p\u003e\n\u003cp\u003eThe concentration of FMIP affects the sensitivity of BPA fluorescence detection. The fluorescence quenching\u0026nbsp;ratio (F\u003csub\u003e0\u003c/sub\u003e-F)/F\u003csub\u003e0\u003c/sub\u003e of FMIP within the concentration range of 0.062-1 mg/mL (where F\u003csub\u003e0\u003c/sub\u003e and F stands for the fluorescence intensities of the FMIP before and after combined with BPA, respectively) was studied. Fig. 3B demonstrates that the maximum (F\u003csub\u003e0\u003c/sub\u003e-F)/F\u003csub\u003e0\u003c/sub\u003e was achieved at a concentration of 0.25 mg/mL, indicating optimal binding between BPA and the imprinted cavities at this concentration. Consequently, the concentration of 0.25 mg/mL was used for all subsequent tests.\u003c/p\u003e\n\u003cp\u003eThe pH value during the detection process significantly influenced the recognition performance of FMIP. The (F\u003csub\u003e0\u003c/sub\u003e-F)/F\u003csub\u003e0\u003c/sub\u003e of the FMIP across a pH range of 4 to 9 was used to evaluate its recognition performance. As shown in Fig. 3C, when the pH is below 7, the (F\u003csub\u003e0\u003c/sub\u003e-F)/F\u003csub\u003e0\u0026nbsp;\u003c/sub\u003eof FMIP increased gradually. At pH 7, the (F\u003csub\u003e0\u003c/sub\u003e-F)/F\u003csub\u003e0\u003c/sub\u003e reached its maximum and subsequently decreased with further increases in pH. This is primarily attributed to the protonation of the amino group in the fluorescent functional monomer under acidic conditions. This protonation prevents the template from forming effective hydrogen bonds with the fluorescent functional monomer. Under alkaline conditions, the phenolic hydroxyl group of BPA undergo deprotonation, forming negatively charged phenoxy anions. The electrostatic repulsion between the imprinted sites and phenolate anions thereby reduces the binding ability of the imprinting cavity[29]. Thus, pH 7 was selected for all fluorescence testing.\u003c/p\u003e\n\u003cp\u003eUnder the above conditions, the effect of incubation time on FMIP fluorescence performance was investigated.\u0026nbsp;The incubation time was determined by observing changes in the fluorescence intensity ratio (F\u003csub\u003e0\u003c/sub\u003e/F) value. From Fig. 3D, the F\u003csub\u003e0\u003c/sub\u003e/F value increased gradually within 12 min, after which it stabilized. Consequently, 8 min was selected as the optimal incubation time for subsequent testing.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2.3 Analytical performance of FMIP\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUnder the optimized parameters, the fluorescence response of FMIP was investigated across a range of BPA concentrations (0-80 \u0026mu;M). As can be seen from Fig. 4A, the fluorescence emission intensity of FMIP at 528 nm gradually decreased with increasing of BPA concentration. According to Fig. 4B, the F\u003csub\u003e0\u003c/sub\u003e/F of FMIP exhibits a good linear relationship with BPA concentrations between 0-80 \u0026mu;M, and the linear regression equation was y=0.00823x+0.99788 (R\u003csup\u003e2\u003c/sup\u003e=0.9983). The limit of detection (LOD) for BPA was calculated to be 0.43 \u0026mu;M, based on the formula LOD=3\u0026delta;/s (\u0026delta; is the standard deviation of the blank measurement, s is the gradient of the calibration curve).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFor comparison, parallel experiments were conducted using FNIP. As shown in Fig. 4C, within the range of 0 to 80 \u0026mu;M, the fluorescence intensity of FNIP also decreased as BPA concentration grew, but the sensitivity was significantly lower than that observed with FMIP.\u0026nbsp;This difference is attributed to the absence of specific binding cavities complementary to BPA in FNIP, resulting in lower sensitivity toward the target analyte.\u0026nbsp;A linear relationship was also obtained for the FNIP between the F\u003csub\u003e0\u003c/sub\u003e/F and the BPA concentration (Fig. 4D), following the linear regression equation y=0.00132x+1.01544 (R\u003csup\u003e2\u003c/sup\u003e=0.9866).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2.4 The selectivity and fluorescence stability of the FMIP sensor for BPA\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe selectivity of the FMIP sensor toward BPA was examined by studying the fluorescence intensity ratio of FMIP in the presence of BPA and its structural analogues.\u0026nbsp;As shown in Fig. 5A, BPA showed the highest F\u003csub\u003e0\u003c/sub\u003e/F for FMIP, indicating the strongest quenching effect. In contrast, its structural analogues\u0026nbsp;showed significantly lower F\u003csub\u003e0\u003c/sub\u003e/F values. This pronounced selectivity originates from the presence of imprinting cavities within the FMIP, which are complementary in size and shape to BPA. In contrast, the FNIP exhibit a low fluorescence emission ratio for BPA and its analog, owing to the lack of specific BPA-imprinted cavities. The above results demonstrate the excellent selectivity of the prepared FMIP for BPA.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe stability of the FMIP is also a critical factor in evaluating sensor performance. The fluorescence stability of FMIP was evaluated by monitoring the fluorescence intensity under room temperature conditions and continuous UV lamp irradiation. As shown in Fig. 5B, after continuous exposure to ultraviolet light for 120 minutes, the fluorescence intensity remained virtually unchanged. Furthermore, store the FMIP solution at room temperature for 7 days. From Fig. 5C, the fluorescence intensity decreased slightly within 7 days, but the change was negligible. Collectively, experimental results indicate that the sensor exhibits excellent stability.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2.5 Mechanism investigation of fluorescence quenching\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe possible quenching mechanism of BPA on the FMIP was investigated. As shown in Fig. S10A, no overlap exists in the UV absorption spectrum of BPA (a) and the emission spectrum of N-allyl-4-ethylenediamine-1, 8-naphthalimide (b), indicating that the fluorescence resonance energy transfer (FRET) was not the cause of fluorescence quenching. Therefore, the photoinduced electron transfer (PET) is the most likely quenching mechanism. In Fig. S10B, the hydroxyl groups in BPA are capable of forming hydrogen bonds with the amino groups found in the fluorescent functional monomer. This interaction facilitates charge transfer from fluorescent functional monomer to BPA, causing fluorescence quenching. Furthermore, molecular orbital theory can also explain this phenomenon. Under ultraviolet light excitation, electrons in the valence band of fluorescent monomers were excited to the conduction band. Excited electrons subsequently revert to the valence band, thereby generating fluorescence. However, when the template BPA binds to the imprint cavity, these excited electrons at the conductive band of fluorescent functional monomer can directly transfer to the lowest unoccupied molecular orbital (LUMO) of BPA, causing fluorescence quenching (Fig. S10C). In summary, the fluorescence quenching observed in the sensor can primarily be explained by the photoinduced electron transfer (PET) process.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2.6 Real sample detection\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo evaluate the accuracy and feasibility of FMIP in detecting BPA in real water samples. The detection of BPA in lake water and tap water was demonstrated by spiked recovery experiments. As listed in Table 1, the recovery rate in real water samples ranged from 96.55% to102.25%, with an RSD between 0.4% and 1.57%. These above results have completely demonstrated that the FMIP sensor can be used for the analysis of BPA in real water samples.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1\u003c/strong\u003e The results of quantitative detection of BPA in water samples by the sensor\u003c/p\u003e\n\u003cdiv align=\"\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"567\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003eSamples\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 113px;\"\u003e\n \u003cp\u003eAdd (\u0026mu;M)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003eFound (\u0026mu;M)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003eRecovery (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003eRSD (%)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003eND\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003eTap water\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e19.3101\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e96.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e0.81\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e39.7656\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e99.41\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e1.18\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e58.4039\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e97.34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e1.57\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003eND\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003eLake water\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e20.4507\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e102.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e0.95\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e39.4777\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e98.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e1.27\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e59.4911\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e99.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003csup\u003ea\u003c/sup\u003e Average of three measurements.\u003c/p\u003e\n\u003cp\u003e\u003csup\u003eb\u003c/sup\u003e relative standard deviation.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003csup\u003ec\u003c/sup\u003e from Keda lake in Shanxi, China.\u003c/p\u003e\n\u003cp\u003e\u003csup\u003ed\u003c/sup\u003e ND: not detection.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2.7 Method performance comparison\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe performance of the fluorescence sensor prepared in this study was compared with other reported sensors (Table 2). While the detection limit of the proposed FMIP sensor is slightly higher than reported in certain existing fluorescent methods for BPA detection, it exhibits excellent selectivity. Furthermore, from a methodological perspective, this work offers a novel approach for BPA detection and demonstrates significant potential for the future detection of low-concentration target analytes.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2\u003c/strong\u003e Performance comparison of fluorescent methods for detecting BPA\u003c/p\u003e\n\u003cdiv align=\"\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"567\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eMethods\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 159px;\"\u003e\n \u003cp\u003eSystem\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003eLinear range(\u0026mu;M)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eLOD(\u0026mu;M)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eReferences\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eFluorescence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 159px;\"\u003e\n \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e@CdTe@MIP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003e1-100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003e0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e[30]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eFluorescence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 159px;\"\u003e\n \u003cp\u003eHPTS/Smart phones\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003e0-88\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003e4.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e[31]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eFluorescence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 159px;\"\u003e\n \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e@AuNCs-MIP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003e0-13.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003e0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e[32]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eFluorescence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 159px;\"\u003e\n \u003cp\u003eSi NPs/HRP/H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003e0-100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003e0.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e[33]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eFluorescence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 159px;\"\u003e\n \u003cp\u003eGQDs-SBA-15/MIP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003e0.5-20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003e0.18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e[34]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eFluorescence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 159px;\"\u003e\n \u003cp\u003eEGMP/MIP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003e5-250\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e[35]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eFluorescence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 159px;\"\u003e\n \u003cp\u003eFMIP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003e0-80\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003e0.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eThis work\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003eFMIP sensor was successfully constructed to detect BPA selectively and sensitively by integrating the specific molecular recognition of MIP with the high sensitivity of fluorescence analysis. The mSiO\u003csub\u003e2\u003c/sub\u003e possesses a high specific surface area, making it suitable to be used as the carrier that can provide more imprinting sites. RAFT agent was grafted onto the mSiO\u003csub\u003e2\u003c/sub\u003e surface via click chemistry. Subsequently, FMIP was synthesized via RAFT polymerization in the presence of fluorescent functional monomers. Experimental results indicate that the fluorescence intensity ratio of FMIP exhibits a good linear relationship with BPA concentration across the 0-80 \u0026mu;M range, achieving a limit of detection at 0.43 \u0026mu;M. Moreover, the FMIP sensor performed effectively in the analysis of BPA in real water samples, achieving recoveries between 96.55% to 102.25%, with RSD ranging from 0.4% to 1.57%. In summary, the FMIP sensor exhibits specific recognition capability for BPA and provides a reliable method for the detection of this target analyte.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp skip=\"true\"\u003e\u003cstrong\u003eCRediT authorship contribution statement\u003c/strong\u003e\u003cstrong\u003e \u003c/strong\u003e\u003c/p\u003e\n\u003cp skip=\"true\"\u003e\u003cstrong\u003eYanming Shao:\u003c/strong\u003e Writing - review \u0026amp; editing, Supervision, Project administration, Funding acquisition. \u003cstrong\u003eXuan Rong:\u003c/strong\u003e Writing - original draft, Methodology, Investigation, Conceptualization. \u003cstrong\u003eHuanhuan Zhao:\u003c/strong\u003e Software, Methodology, Formal analysis, Data curation. \u003cstrong\u003eHuanran Feng:\u003c/strong\u003e Writing - review \u0026amp; editing. \u003cstrong\u003eWenli Ma:\u003c/strong\u003e Validation, Visualization. \u003cstrong\u003eWenli Peng:\u003c/strong\u003e Software, Validation. \u003cstrong\u003eGuohao Gao: \u003c/strong\u003eFormal analysis, Data curation. \u003cstrong\u003eXianyu Yang: \u003c/strong\u003eInvestigation, Data curation. \u003cstrong\u003eZiwei Jiao: \u003c/strong\u003eData curation.\u003c/p\u003e\n\u003cp skip=\"true\"\u003e\u003cstrong\u003eDeclaration of interest statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp skip=\"true\"\u003eThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\u003c/p\u003e\n\u003cp skip=\"true\"\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp skip=\"true\"\u003eThis work was supported by the National Natural Science Foundation of China (Program No. 21806097, 22005234), the Natural Science Basic Research Plan in Shaanxi Province of China (2024JC-YBMS-109, 2025JC-YBQN-588), the Scientific Research Program Funded by Shaanxi Provincial Education Department (Program No. 18JK0104), and Research Starting Foundation of Shaanxi University of Science and Technology (Program No. 2016BJ-80).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAppendix A. Supplementary data\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSchematic illustration of the synthesis of (propargyl 4-cyanopentanate) dithiobenzoate; Schematic illustration of the synthesis of N-allyl-4-ethylenediamine-1, 8-naphthalimide; \u003csup\u003e1\u003c/sup\u003eH NMR spectra of 3-azidopropyltriethoxysilane; \u003csup\u003e1\u003c/sup\u003eH NMR Spectra of (4-cyanopentanoic acid) dithiobenzoate; \u003csup\u003e1\u003c/sup\u003eH NMR spectra of (propargyl 4-cyanopentanate) dithiobenzoate; \u003csup\u003e1\u003c/sup\u003eH NMR Spectra of N-Allyl-1, 8-naphthalimide; \u003csup\u003e1\u003c/sup\u003eH NMR spectra of N-allyl-4-ethylenediamine-1, 8-naphthalimide; FT-IR spectra of SiO\u003csub\u003e2\u003c/sub\u003e, SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-N\u003csub\u003e3\u003c/sub\u003e, SiO\u003csub\u003e2\u003c/sub\u003e@mSiO\u003csub\u003e2\u003c/sub\u003e-PCPADB and FMIP and so on.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData will be made available on request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eLing S, Xu A, Sun M, Li X, Huang Y, Xu Y, Huang J, Xie T, Wang S (2024) Sensitive and rapid detection of bisphenol A using signal amplification nanoparticles loaded with anti-bisphenol A monoclonal antibody. 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Analytical and Bioanalytical Chemistry 416: 7121-7129. https://doi.org/10.1007/s00216-024-05616-y\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Scheme","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":"microchimica-acta","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"miac","sideBox":"Learn more about [Microchimica Acta](https://link.springer.com/journal/604)","snPcode":"604","submissionUrl":"https://submission.springernature.com/new-submission/604/3","title":"Microchimica Acta","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Bisphenol A, Molecularly imprinted polymer, Mesoporous SiO2, Fluorescent sensor, RAFT polymerization","lastPublishedDoi":"10.21203/rs.3.rs-8074508/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8074508/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eA fluorescent molecularly imprinted polymer (FMIP) sensor for sensitive detection of bisphenol A (BPA) was constructed based on surface-initiated reversible addition fragmentation chain transfer (SI-RAFT) polymerization with mesoporous silica (mSiO\u003csub\u003e2\u003c/sub\u003e) as the carrier. In this work, N-allyl-4-ethylenediamine-1, 8-naphthalimide was used as the fluorescent functional monomer and mSiO\u003csub\u003e2\u003c/sub\u003e as the carrier. The high specific surface area of mSiO\u003csub\u003e2\u003c/sub\u003e carrier providing more imprinting sites for the FMIP and thereby effectively enhances recognition efficiency of obtained imprinted polymer. Azide groups were initially grafted onto the mSiO\u003csub\u003e2\u003c/sub\u003e surface, and then alkynyl-functionalized RAFT agent was introduced via copper(I)-catalyzed azide\u0026ndash;alkyne cycloaddition (CuAAC) reaction. The FMIP was synthesized by RAFT polymerization using BPA as the template, methacrylic acid (MAA) as the functional monomer. When the template BPA rebinds to the imprinting cavity, the fluorescence signal of the MIP-capped N-allyl-4-ethylenediamine-1, 8-naphthalimide can be efficiently quenched. The ratio of fluorescence intensity exhibited a linear response to the concentrations of BPA ranging from 0 to 80 \u0026micro;M, achieving a detection limit of 0.43 \u0026micro;M. Moreover, the FMIP sensor was effectively used to detect BPA in real samples, with recovery rates ranging from 96.55% to 102.25% and a relative standard deviation (RSD) of 0.4%-1.57%. The results indicate that the prepared FMIP sensor shows great potential for the detection of BPA in environmental medium.\u003c/p\u003e","manuscriptTitle":"Fluorescent Molecularly Imprinted Polymer Sensor Prepared Using Mesoporous Silica as Carrier for Sensitive and Accurate Detection of Bisphenol A","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-05 07:34:30","doi":"10.21203/rs.3.rs-8074508/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-01-05T15:00:00+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-21T03:05:50+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"310760937978982051182014726244635455447","date":"2025-12-06T01:46:27+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-12-04T01:36:25+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-11-13T09:35:19+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-11-13T01:32:57+00:00","index":"","fulltext":""},{"type":"submitted","content":"Microchimica Acta","date":"2025-11-10T08:19:56+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"microchimica-acta","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"miac","sideBox":"Learn more about [Microchimica Acta](https://link.springer.com/journal/604)","snPcode":"604","submissionUrl":"https://submission.springernature.com/new-submission/604/3","title":"Microchimica Acta","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"9634548c-bde0-46fb-bd45-dbcaed70109d","owner":[],"postedDate":"December 5th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-03-23T16:01:21+00:00","versionOfRecord":{"articleIdentity":"rs-8074508","link":"https://doi.org/10.1007/s00604-026-07947-2","journal":{"identity":"microchimica-acta","isVorOnly":false,"title":"Microchimica Acta"},"publishedOn":"2026-03-17 15:57:26","publishedOnDateReadable":"March 17th, 2026"},"versionCreatedAt":"2025-12-05 07:34:30","video":"","vorDoi":"10.1007/s00604-026-07947-2","vorDoiUrl":"https://doi.org/10.1007/s00604-026-07947-2","workflowStages":[]},"version":"v1","identity":"rs-8074508","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8074508","identity":"rs-8074508","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}