Sensor with strong solid emission for fluorescence colormetric detection of 1, 4-dioxane in Water and vapor based on the Keto-Enol isomerisation

Sensor with strong solid emission for fluorescence colormetric detection of 1, 4-dioxane in Water and vapor based on the Keto-Enol isomerisation | 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 Sensor with strong solid emission for fluorescence colormetric detection of 1, 4-dioxane in Water and vapor based on the Keto-Enol isomerisation Jing Wang, Zi-Ao Zong, Shi-Fu Huang, Mohd. Muddassir, Zhi-Yong Xing, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5824424/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 16 May, 2025 Read the published version in Journal of Fluorescence → Version 1 posted 9 You are reading this latest preprint version Abstract In this work, an easy prepared solid fluorescent sensor 3-(benzo[d]thiazol-2-yl)-1-hydroxy-4-oxo-3,4-dihydrophthalazine-6-carboxylic acid ( BPCA ) was designed and synthesized and the structure was proved by IR, UV-Vis, NMR, HRMS and elemental analysis, which displayed high selectivity and sensitivity for fluorescence colormetric from green to blue sensing 1, 4-dioxane in water, and the detection limit was obtained 0.009% and the stability constant was 7.4×10 4 M. Also, sensor BPCA was applied for the real-time monitoring 1, 4-dioxane vapor with apparent fluorescent color change from green to blue. The mild and specific chemical interaction between sensor BPCA and 1, 4-dioxane molecule allowed the sensor as portable chips to respond 1, 4-dioxane vapor with good selectivity over other common VOCs at room temperature. Also, the sensing mechanism based on the 1, 4-dioxane-induced keto-enol tautomerization of the phthalazine moiety was found and supported by DFT calculations. 1 4-dioxane fluorescence colormetric sensor tautomerization vapor Figures Figure 1 Figure 2 Figure 3 Introduction 1, 4-dioxane, a universal volatile organic compound (VOC) and an important organic solvent has been widely used in dyes, textile, cosmetic, paper industries and polyethylene terephthalate plastic manufacturing processes. 1 – 3 But, 1, 4-dioxane is toxic to humans by inhalation and ingestion, and has been categorized as carcinogenic hazardous solvent and the Environmental Protection Agency, USA, has classified 1, 4-dioxane in group B2. 4 – 6 In addition, 1, 4-dioxane is completely miscible in water, semivolatile, and is thus highly mobile in water or aqueous environments, thus threaten human health seriously. 7 – 9 Therefore, the accurate detection of 1, 4-dioxane in groundwater and vapor phase was necessary and significant for human health. Commonly methods for the determination of 1, 4-dioxane including GC-MS, LC-MS and HPLC-UV. 10 But above techniques possessed some drawbacks, including low sensitivity and expensive equipment. In recent years, fluorescent sensors had developed as a useful tool for analytes detection because of its low cost and rapidity and potential applications in environmental and biological systems. 11 – 18 To data, fluorescence sensor for detection of 1, 4-dioxane were developed. Feng’s team prepared a porous organic polymer, which showed fluorescence turn on response for 1, 4-dioxane. 19 Fan’s team reported a fluorescence sensor based on the naphthalimide for the fluorescence ratiometric sensing 1, 4-dioxane in CHCl 3 . 20 However, these sensors don’t displayed the obvious fluorescence response for 1, 4-dioxane in water and vapor phase. Furthermore, those sensors with fluorescent colormetric response are more attractive on account of the naked-eye observation. 21 – 25 Therefore, the development of fluorescence sensors through fluorescence colorimetric responses for detection of 1, 4-dioxane in water and vapor phase remained a task of seeming urgency. Therefore, a novel sensing 1, 4-dioxane fluorescence sensor BPCA based on a new keto-enol tautomerization strategy was developed. The sensor BPCA interaction with 1, 4-dioxane molecule specifically with apparent fluorescent color change from green to blue. Also, the sensor BPCA successfully was applied to detect the content of 1, 4-dioxane in water. In addition, when the sensor was loaded on the periopaper as a portable sensor for quantitative determination of 1, 4-dioxane in gas phase. Experimental Materials and general characteristics All the materials for synthesis and spectral analysis were commercial available without any additional purification. Please refer to the Supplementary Material for information on the materials used and the general characteristics of the compound. Synthesis of BPCA In Scheme 1 , the compound BPCA was synthesized according to the literature. 26 In Scheme 1 , ,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid (192 mg, 1 mmol) and 2-hydrazinobenzothiazole (165 mg, 1 mmol) were added to 20 mL glacial acetic acid and the mixture was refluxed with stirring for 3 h. Subsequently, the solution was cooled and filtered to obtain green solid BPCA . The data of Elemental analyses C, 56.63; H, 2.67; N, 12.38; O, 18.86; S, 9.45; Found (%): C, 56.36; H, 2.87; N, 12.36; O, 18.96; S, 9.45. 1 H NMR (Fig. S1 ) (DMSO- d 6 , 600 MHz): δ (ppm) 13.42 (s, 1H, -COOH), 11.72 (s, 1H, -OH), 8.47 (m, 1H, benzene-H), 8.34 (s, 1H, benzene-H), 8.12 (m, 1H, benzene-H), 7.79 (m, 1H, benzene-H), 7.41 (m, 1H, benzene-H), 7.30 (t, 1H, benzene-H), 7.17 (t, 1H, benzene-H). 13 C NMR (Fig. S2) (151 MHz, DMSO- d 6 ) δ (ppm) 166.37 (1C, -COOH), 166.13 (1C, -C = O), 164.98 (1C, benzene-C), 148.65 (1C, benzene-H), 137.42 (1C, benzene-H), 136.46 (1C, benzene-H), 133.23 (1C, benzene-H), 130.81 (1C, benzene-H), 130.41 (1C, benzene-H), 126.89 (1C, benzene-H), 126.70 (1C, benzene-H), 124.72 (1C, benzene-H), 124.20 (1C, benzene-H), 123.12 (1C, benzene-H), 122.31 (1C, benzene-H), 122.18 (1C, benzene-H). ESI-MS (Fig. S3): calcd for C 16 H 10 N 3 O 4 S: 340.0392 [ BPCA + H] + , found: 340.0389. UV-vis (Fig. S4): 266 nm (π-π * ), 355 nm (n-π * ). FT-IR (Fig. S5) (KBr pellets): 3450 cm − 1 (-OH), 1605 cm − 1 (C = O), 1480 cm − 1 (C = N), 1435 cm − 1 (C-S), 1325 cm − 1 (C-O). Results and discussion The fluorescence properties studies of BPCA The optical properties of BPCA were examined in solids firstly. In Fig. 1 a, the BPCA showed strong green emission with maximum emission wavelength at 510 nm. Further, the optical properties of BPCA in various solvents, including 1, 4-dioxane (Diox), triethylamine (Et 3 N), water (H 2 O), methanol (MeOH), ethanol (EtOH), dichloromethane (CH 2 Cl 2 ), petroleum ether (PE) and ethyl acetate (EA) were studied by fluorescence spectra. In Fig. 1 b, BPCA in most organic solvents and water exhibited emission bands at 500 nm approximately. It is interesting to note that the emission peak of BPCA in 1, 4-dioxane were obviously blue-shifted to 440 nm. In addition, compared with the green fluorescence in most of the organic solvents being tested, the obvious blue fluorescence was observed in the BPCA 1, 4-dioxane solution, suggesting that BPCA can serve as a visually discernible sensor for 1, 4-dioxane. To explore the potential application of sensor BPCA , the 1, 4-dioxane content in distilled water were systematically measured. In Fig. 1 c, with the addition of 1, 4-dioxane content from 0 to 10%, the emission peak at 410 nm was increased gradually, and the emission peak at 510 nm was blue-shifted to 435 nm along with the increasement of the fluorescence intensity gradually, accompanied by an obvious fluorescence color change from green to blue. In addition, there are a good linear relationships between the fluorescence intensity at 435 nm and 1, 4-dioxane content from 0 to 8%, and the detection limit (LOD) was calculated to be 0.009% (Fig. S6). Based on the non-linear regression analysis 27 , the association constant was determined from fluorescence titration experiments and calculated as 7.4×10 4 M − 1 (Fig. S7). Above results indicated that sensor BPCA could quantitative detect 1, 4-dioxane content in distilled water. Application of portable test strips Since BPCA showed significant fluorescence colormetric response to 1, 4-dioxane, we applied it for the fabrication of a solid 1, 4-dioxane vapor sensor. 28 In Fig. 2 a, the fabricated BPCA -based test strips sensor emitted green fluorescence. Only exposure to acetone vapor, the fluorescence color of the paper-strip changed from green to blue. After exposure to other vapor, including PE, MeOH, EtOH, EA, 1, 4-dioxane, Et 3 N, CH 2 Cl 2 , no obvious fluorescence change of BPCA -based test strips were observed. This results indicated that the BPCA -based test strips could be used to determine the 1, 4-dioxane vapor with high selectivity. We then performed the fluorescence colormetric detection of 1, 4-dioxane vapor by fumigation different time of acetone into a sealed bottle containing the BPCA -based test strips sensor. In Fig. 2 b, with fumigation treatment, the fluorescence color of the corresponding test strips also changed from green to blue. The remarkable fluorescence color change could be easily detected by naked eye, offering the convenience for visual real-time detection 1, 4-dioxane vapor in real-world applications. The sensing mechanism To confirm the detection mechanism of sensor BPCA toward 1, 4-dioxane, we carried out the 1 H NMR (Fig. S8) and FT-IR experiments. After addition of 1, 4-dioxane to BPCA in DMSO d 6 , the OH proton at 11.72 ppm was disappeared. Also, the characteristic OH absorption peak at 3450 cm − 1 was disappeared and the new characteristic NH absorption peak at 3305 cm − 1 and C = O absorption peak at 1793 cm − 1 was observed (Fig. S5). Above results indicated that the addition of 1, 4-dioxane triggered Keto-Enol isomerisation because the hydrogen atom can happen easily between 1, 4-dioxane and molecule that the structure was change easily 29 (Scheme 2 ). Theoretical calculation To further understand the above sensing mechanism, DFT calculations using Gaussian 09 software were carried out for the main molecular forms of BPCA Enol-Keto tautomers (Fig. 3 ). In BPCA Enol, the electron cloud distribution of the lowest unoccupied molecular orbitals (LUMOs, -2.48 eV) and lowest unoccupied molecular orbitals (HOMOs, -6.19 eV) were mainly spread over the whole conjugated skeleton. However, in BPCA Keto ( BPCA /1, 4-dioxane), its electron densities in LUMO (-2.50 eV) and (HOMOs, -6.38 eV) were mainly localized over the phthalazine unit and benzothiadiazole unit. The HOMO-LUMO energy gaps were found to be 3.71 eV for BPCA Enol and 3.88 eV for BPCA Keto. In addition, the measured dihedral angle between the phthalazine and benzothiazole planes in BPCA Keto (36.19°) were larger than the corresponding dihedral angle of BPCA Enol (3.43°), indicating the intramolecular conjugation of BPCA Keto was the weaker, thus BPCA Keto displayed blue shifts in the emission spectra. 26 , 30 – 32 Detection of 1, 4-dioxane in Tap Water The probe BPCA was applicated in the detection of 1, 4-dioxane in real water samples collected from local region of campus by the proposed fluorimetric method. The solution of 1, 4-dioxane at different content levels were spiked in all real samples, respectively. The corresponding results were obtained by proposed method were summarized in Table S1 . These results suggested that the high accuracy of the probe BPCA for detection 1, 4-dioxane in tap water. Conclusions In summary, a colormetric fluorescent sensor named BPCA , which exhibited obvious solid state emission was developed based on 1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid and 2-hydrazineylbenzo[d]thiazole for fluorescence colormetric sensing 1, 4-dioxane in water and vapor with high selectivity and sensitivity (detection limit: 0.009%). Also, the sensing mechanism based on the 1, 4-dioxane-induced keto-enol tautomerization of the phthalazine moiety was found and supported by DFT calculations. Declarations CRediT authorship contribution statement Conceptualization, W.J; methodology, Z.A.Z.; formal analysis, S.F.H and M.M; data curation, Z.Y.X; writing—original draft preparation, N.N.Li.; writing—review and editing, W.Q.J. Conflicts of interest The authors declare no conflict of interest. Author Contribution Jing Wang, Zi-Ao Zong, Shi-Fu Huang, Mohd. Muddassir and Zhi-Yong Xing wrote the main manuscript text. Na-Na Li and Wen-Qiong Jiang prepared figures 1-3, scheme 1 and scheme 2. All authors reviewed the manuscript. Acknowledgements This work was supported by Scientific and Technological Inno-vation Programs of Higher Education Institutions in Shanxi (No. 2022L465), Fundamental Research Program of Shanxi Province (No. 202203021222307), Natural Science Foundation of China (No. 22277104), Xinzhou Teachers University project fund (No. 00001036), the Scientific Research and Technology Development Program Project of Baise City (No.20222001), the Science and Technology Baseand the Talent Special Project for Guangxi Province (No. AD22035154 and AD20297056). Dr. Mohd. Muddassir is grateful to Researchers Supporting Project number (RSP2023R141), King Saud University, Riyadh, Saudi Arabia, for financial assistance. References Sekar R, DiChristina TJ (2014) Environ Sci Technol 48:12858–12867 Isaacson C, Mohr TKG, Field JA (2006) Environ Sci Technol 40:7305–7311 Deng DY, Li F, Li MY (2014) Environ. Sci. Technol. Lett. , 5 (2), (2014) 86–91 Chen H, Zheng X, Cooks RG (2003) J Am Soc Mass Spectrom 14:182–188 Lee CS, Wang M, Clyde PM, Mao X, Brownawell BJ, Venkatesan AK (2023) Chemosphere 324:138304 DeRosa CT, Wilbur S, Holler J, Richter P, Stevens YW (1996) Toxicol Ind Health 12(1):1–43 Tan X, Chen S, Luo Q, You S, Yuan H, Wang J (2024) J Cell Mol Med 28:e18018 McElroy AC, Ogles ME, Hyman MR, Knappe DRU (2023) Water Res 231:119652 Stickney JA, Sager SL, Clarkson JR, Smith LA, Locey BJ, Bock MJ, Hartung R, Olp SF (2003) Regul Toxicol Pharmacol 38:183–195 Fei L, Deng D, Wadden A, Parvis P, Cutt D, Li M (2023) J Hazard Mater Adv 9:100246 Zhu H, Fan JL, Wang J, Mu H, Peng XJ (2014) J Am Chem Soc 136:12820–12823 Pan GJ, Xia TT, He Y (2021) Talanta 221:121434 Liu HP, Lu ZQ, Ye KQ, Zhang ZL, Zhang HY (2019) ACS Appl Mater Interfaces 11:34526–34531 Yue YK, Huo FJ, Li XQ, Wen Y, Yi T, Salamanca J, Escobedo JO, Strongin RM, Yin CX (2017) Org Lett 19:82–85 Li KB, Qu WB, Han DM, Zhang SQ, Shi W, Chen CX (2019) X X Liang Talanta 194:803–808 Yang YT, Zhou TT, Jin M, Zhou KY, Liu DD, Li X, Huo FJ, Li W, Yin CX (2020) J Am Chem Soc 142:1614–1620 Li NN, Lu ZW, Bi CF, Xue J, Ma KX, Wu RX, Fan CB, Xu CG, Zhang X (2021) Microchem J 163:105898 Zhang SQ, Chen DW, Yan LQ, Xie Y, Mu XY, Zhu JB (2020) Microchem J 157:105066 Ma D, Li B, Cui Z, Liu K, Chen C, Li G, Hua J, Ma B, Shi Z, Feng. S (2016) ACS Appl Mater Interfaces 8:24097–24103 Li NN, Liu WB, Shi NN, Yang D, Zong ZA, Zhang X, Wu RX, Xu CG, Bi SY, Fan YH (2021) Dyes Pigm 188:109172 Gong D, Han SC, Iqbal A, Qian J, Cao T, Liu W, Liu W, Qin W, Guo H (2017) Anal Chem 89:13112–13119 Li NN, Liu WB, Shi NN, Yang D, Zong ZA, Zhang X, Wu RX, Xu CG, Bi SY, Fan YH (2021) Dyes Pigm 188:109172 Yuan X, Leng TH, Guo ZQ, Wang CY, Li JZ, Yang WW, Zhu WH (2019) Dyes Pigm 161:403–410 Wang Z, Zhang Y, Song J, Li M, Yang Y, Xu X, Xu H, Wang S (2019) Sens Actuators B Chem 284:148–158 Liu ZX, Zhou X, Miao Y, Hu Y, Kwon N, Wu X, Yoon J (2017) Angew Chem Int Ed 56:1–6 Li NN, Shi NN, Yang D, Wu RX, Xu CG, Zhu B, Shao F, Zhang X, Bi SY, Fan YH (2021) J Mol Liq 342:116946 Dong M, Ma TH, Zhang AJ, Dong YM, Wang YW, Peng Y (2010) Dyes Pigm 87:164e172 Xu C, Zhou Y, Li Z, Zhou Y, Liu X, Peng X (2021) J Hazard Mater 418:126243 Li N, Liu W, Shi N, Yang D, Zong Z, Zhang X, Wu R, Xu C, Bi S, Fan Y Dyes Pigm 2021,188, 109172 Qi Q, Jiang S, Q Q, Wei J, Xu B, Lu X, Xu Z, Tian W (2020) Chin Chem Lett 31:2985–2987 Ostakhov SS, Ovchinnikov MY, Masyagutova GA, Khursan SL (2019) J Phys Chem A 123:7956–7964 Qi Q, Huang L, Yang R, Li J, Qiao Q, Xu B, Tian W, Liu X, Xu Z (2019) Chem Commun 55:1446–1449 Scheme Schemes 1 and 2 are available in the Supplementary Files section Additional Declarations No competing interests reported. Supplementary Files SupplementaryMaterial.docx Scheme1.png Scheme 1. The synthesis route of BPCA. Scheme2.png Scheme 2. The plausible sensing mechanism for 1, 4-dioxane Cite Share Download PDF Status: Published Journal Publication published 16 May, 2025 Read the published version in Journal of Fluorescence → Version 1 posted Editorial decision: Revision requested 29 Jan, 2025 Reviews received at journal 29 Jan, 2025 Reviews received at journal 28 Jan, 2025 Reviewers agreed at journal 23 Jan, 2025 Reviewers agreed at journal 23 Jan, 2025 Reviewers invited by journal 23 Jan, 2025 Editor assigned by journal 14 Jan, 2025 Submission checks completed at journal 14 Jan, 2025 First submitted to journal 14 Jan, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5824424","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":401898063,"identity":"46695305-e700-493d-9c43-bd0e2ff14fdd","order_by":0,"name":"Jing Wang","email":"","orcid":"","institution":"Youjiang Medical University for Nationalities","correspondingAuthor":false,"prefix":"","firstName":"Jing","middleName":"","lastName":"Wang","suffix":""},{"id":401898064,"identity":"6aa08734-f725-4ae2-932f-7163f9b29535","order_by":1,"name":"Zi-Ao Zong","email":"","orcid":"","institution":"Medical University for Nationalities), Education Department of Guangxi Zhuang Autonomous Region","correspondingAuthor":false,"prefix":"","firstName":"Zi-Ao","middleName":"","lastName":"Zong","suffix":""},{"id":401898065,"identity":"491f4856-2cb8-4563-b600-3db472b10c54","order_by":2,"name":"Shi-Fu Huang","email":"","orcid":"","institution":"Youjiang Medical University for Nationalities","correspondingAuthor":false,"prefix":"","firstName":"Shi-Fu","middleName":"","lastName":"Huang","suffix":""},{"id":401898066,"identity":"23e0ed70-6d0c-4e3a-a28a-ad8326c89951","order_by":3,"name":"Mohd. Muddassir","email":"","orcid":"","institution":"King Saud University","correspondingAuthor":false,"prefix":"","firstName":"Mohd.","middleName":"","lastName":"Muddassir","suffix":""},{"id":401898067,"identity":"ddfea89e-78f8-4a7b-80d2-68a89b47f28c","order_by":4,"name":"Zhi-Yong Xing","email":"","orcid":"","institution":"Youjiang Medical University for Nationalities","correspondingAuthor":false,"prefix":"","firstName":"Zhi-Yong","middleName":"","lastName":"Xing","suffix":""},{"id":401898068,"identity":"c592a6f4-0b2e-45f8-8999-bbc2d600516f","order_by":5,"name":"Na-Na Li","email":"","orcid":"","institution":"Medical University for Nationalities), Education Department of Guangxi Zhuang Autonomous Region","correspondingAuthor":false,"prefix":"","firstName":"Na-Na","middleName":"","lastName":"Li","suffix":""},{"id":401898069,"identity":"38a60887-9d11-4af2-90cd-d5f872f6dff1","order_by":6,"name":"Wen Qiong Jiang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABD0lEQVRIiWNgGAWjYBACxmYQaWBjxzj/8IEDCT8k5NjYmw8QoaUgLZl5BlvigY89NsZ8PMcSiLDrw2HG9hk8ygdnsKUlzpPIUcCrmLmd+dnDLwbMzLyzexgO8/AcTm9jyGFg+FGxDY/D2MyNZQzY+CTnnD1wmMficG4bw9kDjD1nbuPzi5m0hAEPs2FDXgLIltw2xr4EZsY2fFrYvwG1SDDuP5BjcJiH7XA6GzOPAQEtPGaSHwwMGBtn5BiAvJ/AxkZYS5k0g0FCMmPPsQRQIBu28bAlHMTnF8P+49skf/z5b8fY3nz4AzAq5eXnPz744EcFHi0NwIDmQRc9gFM9EMiDHPcDn4pRMApGwSgYBQCkcVtGWiBwwgAAAABJRU5ErkJggg==","orcid":"","institution":"Affiliated Hospital of Youjiang Medical University for Nationalities","correspondingAuthor":true,"prefix":"","firstName":"Wen","middleName":"Qiong","lastName":"Jiang","suffix":""}],"badges":[],"createdAt":"2025-01-14 06:08:20","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5824424/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5824424/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10895-025-04296-w","type":"published","date":"2025-05-16T15:57:45+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":73863072,"identity":"ca508931-57ef-4f65-9de3-402d61d1dd31","added_by":"auto","created_at":"2025-01-15 11:22:10","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":172153,"visible":true,"origin":"","legend":"\u003cp\u003e(a) The emission spectra of \u003cstrong\u003eBPCA\u003c/strong\u003e in solid state. (b) The fluorescence spectra of \u003cstrong\u003eBPCA\u003c/strong\u003e in various solvents. (c)\u003cstrong\u003e \u003c/strong\u003eFluorescence titration spectra of \u003cstrong\u003eBPCA\u003c/strong\u003e after addition of different content of 1, 4-dioxane in water; Inset displays the corresponding solution color changes under 365 nm UV lamp. λ\u003csub\u003eex\u003c/sub\u003e = 360 nm, slit: 5 nm/5 nm.\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5824424/v1/e0637939cc387d1b8e132260.jpg"},{"id":73863826,"identity":"ff38825d-cc75-4981-9d46-3e0c1bdb9512","added_by":"auto","created_at":"2025-01-15 11:30:10","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":131300,"visible":true,"origin":"","legend":"\u003cp\u003e(a) The photograph of sensor \u003cstrong\u003eBPCA\u003c/strong\u003e pre-stained filter paper in the presence of different kinds of solvent vapor under 365 nm UV light. (b) The photograph of sensor \u003cstrong\u003eBPCA\u003c/strong\u003epre-stained filter paper after fumigation treatmentwith different concentrations of 1, 4-dioxane vapor under 365 nm UV light.\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5824424/v1/37145bbc15c199902d498096.jpg"},{"id":73863069,"identity":"15103857-280c-428a-a7ec-624c2b1d2d72","added_by":"auto","created_at":"2025-01-15 11:22:10","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":201824,"visible":true,"origin":"","legend":"\u003cp\u003eThe calculated molecular orbitals and the HOMO-LUMO gaps of \u003cstrong\u003eBPCA \u003c/strong\u003eEnol and \u003cstrong\u003eBPCA \u003c/strong\u003eKeto (\u003cstrong\u003eBPCA\u003c/strong\u003e/1, 4-dioxane).\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5824424/v1/3928f8be1d76e2ed7be42957.jpg"},{"id":83067799,"identity":"c3dbaa0d-71e8-4005-a680-ced0f15fbb13","added_by":"auto","created_at":"2025-05-19 16:06:20","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1103110,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5824424/v1/6ba5c192-f91b-44e5-ac7d-0ec10c0d4acc.pdf"},{"id":73864207,"identity":"23c1eb59-9923-4d4e-9c61-920929bdcedf","added_by":"auto","created_at":"2025-01-15 11:38:10","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":815088,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryMaterial.docx","url":"https://assets-eu.researchsquare.com/files/rs-5824424/v1/4655bfbc8849543bc0054109.docx"},{"id":73863068,"identity":"18b8a75e-fafb-4bbb-a028-3f259e4e15f2","added_by":"auto","created_at":"2025-01-15 11:22:09","extension":"png","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":24003,"visible":true,"origin":"","legend":"\u003cp\u003eScheme 1. The synthesis route of \u003cstrong\u003eBPCA\u003c/strong\u003e.\u003c/p\u003e","description":"","filename":"Scheme1.png","url":"https://assets-eu.researchsquare.com/files/rs-5824424/v1/fe9bd86d63f64c6ed5dd6070.png"},{"id":73863086,"identity":"e178dd44-d6ee-42a4-8b02-aece9d94c814","added_by":"auto","created_at":"2025-01-15 11:22:10","extension":"png","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":222197,"visible":true,"origin":"","legend":"\u003cp\u003eScheme 2. The plausible sensing mechanism for 1, 4-dioxane\u003c/p\u003e","description":"","filename":"Scheme2.png","url":"https://assets-eu.researchsquare.com/files/rs-5824424/v1/8a776de6cc28a6d88e392ba5.png"}],"financialInterests":"No competing interests reported.","formattedTitle":"Sensor with strong solid emission for fluorescence colormetric detection of 1, 4-dioxane in Water and vapor based on the Keto-Enol isomerisation","fulltext":[{"header":"Introduction","content":"\u003cp\u003e1, 4-dioxane, a universal volatile organic compound (VOC) and an important organic solvent has been widely used in dyes, textile, cosmetic, paper industries and polyethylene terephthalate plastic manufacturing processes.\u003csup\u003e\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e But, 1, 4-dioxane is toxic to humans by inhalation and ingestion, and has been categorized as carcinogenic hazardous solvent and the Environmental Protection Agency, USA, has classified 1, 4-dioxane in group B2.\u003csup\u003e\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e In addition, 1, 4-dioxane is completely miscible in water, semivolatile, and is thus highly mobile in water or aqueous environments, thus threaten human health seriously.\u003csup\u003e\u003cspan additionalcitationids=\"CR8\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e Therefore, the accurate detection of 1, 4-dioxane in groundwater and vapor phase was necessary and significant for human health.\u003c/p\u003e \u003cp\u003eCommonly methods for the determination of 1, 4-dioxane including GC-MS, LC-MS and HPLC-UV.\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e But above techniques possessed some drawbacks, including low sensitivity and expensive equipment. In recent years, fluorescent sensors had developed as a useful tool for analytes detection because of its low cost and rapidity and potential applications in environmental and biological systems.\u003csup\u003e\u003cspan additionalcitationids=\"CR12 CR13 CR14 CR15 CR16 CR17\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e To data, fluorescence sensor for detection of 1, 4-dioxane were developed. Feng\u0026rsquo;s team prepared a porous organic polymer, which showed fluorescence turn on response for 1, 4-dioxane.\u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e Fan\u0026rsquo;s team reported a fluorescence sensor based on the naphthalimide for the fluorescence ratiometric sensing 1, 4-dioxane in CHCl\u003csub\u003e3\u003c/sub\u003e.\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e However, these sensors don\u0026rsquo;t displayed the obvious fluorescence response for 1, 4-dioxane in water and vapor phase. Furthermore, those sensors with fluorescent colormetric response are more attractive on account of the naked-eye observation.\u003csup\u003e\u003cspan additionalcitationids=\"CR22 CR23 CR24\" citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e Therefore, the development of fluorescence sensors through fluorescence colorimetric responses for detection of 1, 4-dioxane in water and vapor phase remained a task of seeming urgency.\u003c/p\u003e \u003cp\u003eTherefore, a novel sensing 1, 4-dioxane fluorescence sensor \u003cb\u003eBPCA\u003c/b\u003e based on a new keto-enol tautomerization strategy was developed. The sensor \u003cb\u003eBPCA\u003c/b\u003e interaction with 1, 4-dioxane molecule specifically with apparent fluorescent color change from green to blue. Also, the sensor \u003cb\u003eBPCA\u003c/b\u003e successfully was applied to detect the content of 1, 4-dioxane in water. In addition, when the sensor was loaded on the periopaper as a portable sensor for quantitative determination of 1, 4-dioxane in gas phase.\u003c/p\u003e"},{"header":"Experimental","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eMaterials and general characteristics\u003c/h2\u003e \u003cp\u003eAll the materials for synthesis and spectral analysis were commercial available without any additional purification. Please refer to the Supplementary Material for information on the materials used and the general characteristics of the compound.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eSynthesis of BPCA\u003c/h3\u003e\n\u003cp\u003eIn Scheme \u003cspan refid=\"Sch1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, the compound \u003cb\u003eBPCA\u003c/b\u003e was synthesized according to the literature.\u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e In Scheme\u0026nbsp;\u003cspan refid=\"Sch1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, ,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid (192 mg, 1 mmol) and 2-hydrazinobenzothiazole (165 mg, 1 mmol) were added to 20 mL glacial acetic acid and the mixture was refluxed with stirring for 3 h. Subsequently, the solution was cooled and filtered to obtain green solid \u003cb\u003eBPCA\u003c/b\u003e. The data of Elemental analyses C, 56.63; H, 2.67; N, 12.38; O, 18.86; S, 9.45; Found (%): C, 56.36; H, 2.87; N, 12.36; O, 18.96; S, 9.45. \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003eH NMR (Fig. \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e) (DMSO-\u003cem\u003ed\u003c/em\u003e\u003csub\u003e6\u003c/sub\u003e, 600 MHz): δ (ppm) 13.42 (s, 1H, -COOH), 11.72 (s, 1H, -OH), 8.47 (m, 1H, benzene-H), 8.34 (s, 1H, benzene-H), 8.12 (m, 1H, benzene-H), 7.79 (m, 1H, benzene-H), 7.41 (m, 1H, benzene-H), 7.30 (t, 1H, benzene-H), 7.17 (t, 1H, benzene-H). \u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003eC NMR (Fig. S2) (151 MHz, DMSO-\u003cem\u003ed\u003c/em\u003e\u003csub\u003e6\u003c/sub\u003e) δ (ppm) 166.37 (1C, -COOH), 166.13 (1C, -C\u0026thinsp;=\u0026thinsp;O), 164.98 (1C, benzene-C), 148.65 (1C, benzene-H), 137.42 (1C, benzene-H), 136.46 (1C, benzene-H), 133.23 (1C, benzene-H), 130.81 (1C, benzene-H), 130.41 (1C, benzene-H), 126.89 (1C, benzene-H), 126.70 (1C, benzene-H), 124.72 (1C, benzene-H), 124.20 (1C, benzene-H), 123.12 (1C, benzene-H), 122.31 (1C, benzene-H), 122.18 (1C, benzene-H). ESI-MS (Fig. S3): calcd for C\u003csub\u003e16\u003c/sub\u003eH\u003csub\u003e10\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003eS: 340.0392 [\u003cb\u003eBPCA\u003c/b\u003e\u0026thinsp;+\u0026thinsp;H]\u003csup\u003e+\u003c/sup\u003e, found: 340.0389. UV-vis (Fig. S4): 266 nm (π-π\u003csup\u003e*\u003c/sup\u003e), 355 nm (n-π\u003csup\u003e*\u003c/sup\u003e). FT-IR (Fig. S5) (KBr pellets): 3450 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (-OH), 1605 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (C\u0026thinsp;=\u0026thinsp;O), 1480 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (C\u0026thinsp;=\u0026thinsp;N), 1435 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (C-S), 1325 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (C-O).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Results and discussion","content":"\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eThe fluorescence properties studies of BPCA\u003c/h2\u003e \u003cp\u003eThe optical properties of \u003cb\u003eBPCA\u003c/b\u003e were examined in solids firstly. In Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea, the \u003cb\u003eBPCA\u003c/b\u003e showed strong green emission with maximum emission wavelength at 510 nm. Further, the optical properties of \u003cb\u003eBPCA\u003c/b\u003e in various solvents, including 1, 4-dioxane (Diox), triethylamine (Et\u003csub\u003e3\u003c/sub\u003eN), water (H\u003csub\u003e2\u003c/sub\u003eO), methanol (MeOH), ethanol (EtOH), dichloromethane (CH\u003csub\u003e2\u003c/sub\u003eCl\u003csub\u003e2\u003c/sub\u003e), petroleum ether (PE) and ethyl acetate (EA) were studied by fluorescence spectra. In Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb, \u003cb\u003eBPCA\u003c/b\u003e in most organic solvents and water exhibited emission bands at 500 nm approximately. It is interesting to note that the emission peak of \u003cb\u003eBPCA\u003c/b\u003e in 1, 4-dioxane were obviously blue-shifted to 440 nm. In addition, compared with the green fluorescence in most of the organic solvents being tested, the obvious blue fluorescence was observed in the \u003cb\u003eBPCA\u003c/b\u003e 1, 4-dioxane solution, suggesting that \u003cb\u003eBPCA\u003c/b\u003e can serve as a visually discernible sensor for 1, 4-dioxane.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eTo explore the potential application of sensor \u003cb\u003eBPCA\u003c/b\u003e, the 1, 4-dioxane content in distilled water were systematically measured. In Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec, with the addition of 1, 4-dioxane content from 0 to 10%, the emission peak at 410 nm was increased gradually, and the emission peak at 510 nm was blue-shifted to 435 nm along with the increasement of the fluorescence intensity gradually, accompanied by an obvious fluorescence color change from green to blue. In addition, there are a good linear relationships between the fluorescence intensity at 435 nm and 1, 4-dioxane content from 0 to 8%, and the detection limit (LOD) was calculated to be 0.009% (Fig. S6). Based on the non-linear regression analysis\u003csup\u003e\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u003c/sup\u003e, the association constant was determined from fluorescence titration experiments and calculated as 7.4\u0026times;10\u003csup\u003e4\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (Fig. S7). Above results indicated that sensor \u003cb\u003eBPCA\u003c/b\u003e could quantitative detect 1, 4-dioxane content in distilled water.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eApplication of portable test strips\u003c/h3\u003e\n\u003cp\u003eSince \u003cb\u003eBPCA\u003c/b\u003e showed significant fluorescence colormetric response to 1, 4-dioxane, we applied it for the fabrication of a solid 1, 4-dioxane vapor sensor.\u003csup\u003e\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e In Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea, the fabricated \u003cb\u003eBPCA\u003c/b\u003e-based test strips sensor emitted green fluorescence. Only exposure to acetone vapor, the fluorescence color of the paper-strip changed from green to blue. After exposure to other vapor, including PE, MeOH, EtOH, EA, 1, 4-dioxane, Et\u003csub\u003e3\u003c/sub\u003eN, CH\u003csub\u003e2\u003c/sub\u003eCl\u003csub\u003e2\u003c/sub\u003e, no obvious fluorescence change of \u003cb\u003eBPCA\u003c/b\u003e-based test strips were observed. This results indicated that the \u003cb\u003eBPCA\u003c/b\u003e-based test strips could be used to determine the 1, 4-dioxane vapor with high selectivity.\u003c/p\u003e \u003cp\u003eWe then performed the fluorescence colormetric detection of 1, 4-dioxane vapor by fumigation different time of acetone into a sealed bottle containing the \u003cb\u003eBPCA\u003c/b\u003e-based test strips sensor. In Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb, with fumigation treatment, the fluorescence color of the corresponding test strips also changed from green to blue. The remarkable fluorescence color change could be easily detected by naked eye, offering the convenience for visual real-time detection 1, 4-dioxane vapor in real-world applications.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eThe sensing mechanism\u003c/h2\u003e \u003cp\u003eTo confirm the detection mechanism of sensor \u003cb\u003eBPCA\u003c/b\u003e toward 1, 4-dioxane, we carried out the \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003eH NMR (Fig. S8) and FT-IR experiments. After addition of 1, 4-dioxane to \u003cb\u003eBPCA\u003c/b\u003e in DMSO \u003cem\u003ed\u003c/em\u003e\u003csub\u003e6\u003c/sub\u003e, the OH proton at 11.72 ppm was disappeared. Also, the characteristic OH absorption peak at 3450 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e was disappeared and the new characteristic NH absorption peak at 3305 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and C\u0026thinsp;=\u0026thinsp;O absorption peak at 1793 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e was observed (Fig. S5). Above results indicated that the addition of 1, 4-dioxane triggered Keto-Enol isomerisation because the hydrogen atom can happen easily between 1, 4-dioxane and molecule that the structure was change easily\u003csup\u003e\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u003c/sup\u003e (Scheme \u003cspan refid=\"Sch2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eTheoretical calculation\u003c/h3\u003e\n\u003cp\u003eTo further understand the above sensing mechanism, DFT calculations using Gaussian 09 software were carried out for the main molecular forms of \u003cb\u003eBPCA\u003c/b\u003e Enol-Keto tautomers (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). In \u003cb\u003eBPCA\u003c/b\u003e Enol, the electron cloud distribution of the lowest unoccupied molecular orbitals (LUMOs, -2.48 eV) and lowest unoccupied molecular orbitals (HOMOs, -6.19 eV) were mainly spread over the whole conjugated skeleton. However, in \u003cb\u003eBPCA\u003c/b\u003e Keto (\u003cb\u003eBPCA\u003c/b\u003e/1, 4-dioxane), its electron densities in LUMO (-2.50 eV) and (HOMOs, -6.38 eV) were mainly localized over the phthalazine unit and benzothiadiazole unit. The HOMO-LUMO energy gaps were found to be 3.71 eV for \u003cb\u003eBPCA\u003c/b\u003e Enol and 3.88 eV for \u003cb\u003eBPCA\u003c/b\u003e Keto. In addition, the measured dihedral angle between the phthalazine and benzothiazole planes in \u003cb\u003eBPCA\u003c/b\u003e Keto (36.19\u0026deg;) were larger than the corresponding dihedral angle of \u003cb\u003eBPCA\u003c/b\u003e Enol (3.43\u0026deg;), indicating the intramolecular conjugation of \u003cb\u003eBPCA\u003c/b\u003e Keto was the weaker, thus \u003cb\u003eBPCA\u003c/b\u003e Keto displayed blue shifts in the emission spectra.\u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan additionalcitationids=\"CR31\" citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eDetection of 1, 4-dioxane in Tap Water\u003c/h2\u003e \u003cp\u003eThe probe \u003cb\u003eBPCA\u003c/b\u003e was applicated in the detection of 1, 4-dioxane in real water samples collected from local region of campus by the proposed fluorimetric method. The solution of 1, 4-dioxane at different content levels were spiked in all real samples, respectively. The corresponding results were obtained by proposed method were summarized in Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e. These results suggested that the high accuracy of the probe \u003cb\u003eBPCA\u003c/b\u003e for detection 1, 4-dioxane in tap water.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn summary, a colormetric fluorescent sensor named \u003cb\u003eBPCA\u003c/b\u003e, which exhibited obvious solid state emission was developed based on 1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid and 2-hydrazineylbenzo[d]thiazole for fluorescence colormetric sensing 1, 4-dioxane in water and vapor with high selectivity and sensitivity (detection limit: 0.009%). Also, the sensing mechanism based on the 1, 4-dioxane-induced keto-enol tautomerization of the phthalazine moiety was found and supported by DFT calculations.\u003c/p\u003e "},{"header":"Declarations","content":"\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eCRediT authorship contribution statement\u003c/h2\u003e \u003cp\u003eConceptualization, W.J; methodology, Z.A.Z.; formal analysis, S.F.H and M.M; data curation, Z.Y.X; writing\u0026mdash;original draft preparation, N.N.Li.; writing\u0026mdash;review and editing, W.Q.J.\u003c/p\u003e \u003c/div\u003e\u003cp\u003e \u003ch2\u003eConflicts of interest\u003c/h2\u003e \u003cp\u003eThe authors declare no conflict of interest.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eJing Wang, Zi-Ao Zong, Shi-Fu Huang, Mohd. Muddassir and Zhi-Yong Xing wrote the main manuscript text. Na-Na Li and Wen-Qiong Jiang prepared figures 1-3, scheme 1 and scheme 2. All authors reviewed the manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgements\u003c/h2\u003e \u003cp\u003eThis work was supported by Scientific and Technological Inno-vation Programs of Higher Education Institutions in Shanxi (No. 2022L465), Fundamental Research Program of Shanxi Province (No. 202203021222307), Natural Science Foundation of China (No. 22277104), Xinzhou Teachers University project fund (No. 00001036), the Scientific Research and Technology Development Program Project of Baise City (No.20222001), the Science and Technology Baseand the Talent Special Project for Guangxi Province (No. AD22035154 and AD20297056). Dr. Mohd. Muddassir is grateful to Researchers Supporting Project number (RSP2023R141), King Saud University, Riyadh, Saudi Arabia, for financial assistance.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSekar R, DiChristina TJ (2014) Environ Sci Technol 48:12858\u0026ndash;12867\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIsaacson C, Mohr TKG, Field JA (2006) Environ Sci Technol 40:7305\u0026ndash;7311\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDeng DY, Li F, Li MY (2014) \u003cem\u003eEnviron. Sci. Technol. Lett.\u003c/em\u003e, 5 (2), (2014) 86\u0026ndash;91\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen H, Zheng X, Cooks RG (2003) J Am Soc Mass Spectrom 14:182\u0026ndash;188\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLee CS, Wang M, Clyde PM, Mao X, Brownawell BJ, Venkatesan AK (2023) Chemosphere 324:138304\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDeRosa CT, Wilbur S, Holler J, Richter P, Stevens YW (1996) Toxicol Ind Health 12(1):1\u0026ndash;43\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTan X, Chen S, Luo Q, You S, Yuan H, Wang J (2024) J Cell Mol Med 28:e18018\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcElroy AC, Ogles ME, Hyman MR, Knappe DRU (2023) Water Res 231:119652\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStickney JA, Sager SL, Clarkson JR, Smith LA, Locey BJ, Bock MJ, Hartung R, Olp SF (2003) Regul Toxicol Pharmacol 38:183\u0026ndash;195\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFei L, Deng D, Wadden A, Parvis P, Cutt D, Li M (2023) J Hazard Mater Adv 9:100246\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhu H, Fan JL, Wang J, Mu H, Peng XJ (2014) J Am Chem Soc 136:12820\u0026ndash;12823\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePan GJ, Xia TT, He Y (2021) Talanta 221:121434\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu HP, Lu ZQ, Ye KQ, Zhang ZL, Zhang HY (2019) ACS Appl Mater Interfaces 11:34526\u0026ndash;34531\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYue YK, Huo FJ, Li XQ, Wen Y, Yi T, Salamanca J, Escobedo JO, Strongin RM, Yin CX (2017) Org Lett 19:82\u0026ndash;85\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi KB, Qu WB, Han DM, Zhang SQ, Shi W, Chen CX (2019) X X Liang Talanta 194:803\u0026ndash;808\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYang YT, Zhou TT, Jin M, Zhou KY, Liu DD, Li X, Huo FJ, Li W, Yin CX (2020) J Am Chem Soc 142:1614\u0026ndash;1620\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi NN, Lu ZW, Bi CF, Xue J, Ma KX, Wu RX, Fan CB, Xu CG, Zhang X (2021) Microchem J 163:105898\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang SQ, Chen DW, Yan LQ, Xie Y, Mu XY, Zhu JB (2020) Microchem J 157:105066\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMa D, Li B, Cui Z, Liu K, Chen C, Li G, Hua J, Ma B, Shi Z, Feng. S (2016) ACS Appl Mater Interfaces 8:24097\u0026ndash;24103\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi NN, Liu WB, Shi NN, Yang D, Zong ZA, Zhang X, Wu RX, Xu CG, Bi SY, Fan YH (2021) Dyes Pigm 188:109172\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGong D, Han SC, Iqbal A, Qian J, Cao T, Liu W, Liu W, Qin W, Guo H (2017) Anal Chem 89:13112\u0026ndash;13119\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi NN, Liu WB, Shi NN, Yang D, Zong ZA, Zhang X, Wu RX, Xu CG, Bi SY, Fan YH (2021) Dyes Pigm 188:109172\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYuan X, Leng TH, Guo ZQ, Wang CY, Li JZ, Yang WW, Zhu WH (2019) Dyes Pigm 161:403\u0026ndash;410\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang Z, Zhang Y, Song J, Li M, Yang Y, Xu X, Xu H, Wang S (2019) Sens Actuators B Chem 284:148\u0026ndash;158\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu ZX, Zhou X, Miao Y, Hu Y, Kwon N, Wu X, Yoon J (2017) Angew Chem Int Ed 56:1\u0026ndash;6\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi NN, Shi NN, Yang D, Wu RX, Xu CG, Zhu B, Shao F, Zhang X, Bi SY, Fan YH (2021) J Mol Liq 342:116946\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDong M, Ma TH, Zhang AJ, Dong YM, Wang YW, Peng Y (2010) Dyes Pigm 87:164e172\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXu C, Zhou Y, Li Z, Zhou Y, Liu X, Peng X (2021) J Hazard Mater 418:126243\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi N, Liu W, Shi N, Yang D, Zong Z, Zhang X, Wu R, Xu C, Bi S, Fan Y Dyes Pigm 2021,188, 109172\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eQi Q, Jiang S, Q Q, Wei J, Xu B, Lu X, Xu Z, Tian W (2020) Chin Chem Lett 31:2985\u0026ndash;2987\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOstakhov SS, Ovchinnikov MY, Masyagutova GA, Khursan SL (2019) J Phys Chem A 123:7956\u0026ndash;7964\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eQi Q, Huang L, Yang R, Li J, Qiao Q, Xu B, Tian W, Liu X, Xu Z (2019) Chem Commun 55:1446\u0026ndash;1449\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Scheme ","content":"\u003cp\u003eSchemes 1 and 2 are available in the Supplementary Files section\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"journal-of-fluorescence","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jofl","sideBox":"Learn more about [Journal of Fluorescence](https://www.springer.com/journal/10895)","snPcode":"10895","submissionUrl":"https://submission.nature.com/new-submission/10895/3","title":"Journal of Fluorescence","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"1, 4-dioxane, fluorescence colormetric sensor, tautomerization, vapor","lastPublishedDoi":"10.21203/rs.3.rs-5824424/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5824424/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIn this work, an easy prepared solid fluorescent sensor 3-(benzo[d]thiazol-2-yl)-1-hydroxy-4-oxo-3,4-dihydrophthalazine-6-carboxylic acid (\u003cb\u003eBPCA\u003c/b\u003e) was designed and synthesized and the structure was proved by IR, UV-Vis, NMR, HRMS and elemental analysis, which displayed high selectivity and sensitivity for fluorescence colormetric from green to blue sensing 1, 4-dioxane in water, and the detection limit was obtained 0.009% and the stability constant was 7.4\u0026times;10\u003csup\u003e4\u003c/sup\u003e M. Also, sensor \u003cb\u003eBPCA\u003c/b\u003e was applied for the real-time monitoring 1, 4-dioxane vapor with apparent fluorescent color change from green to blue. The mild and specific chemical interaction between sensor \u003cb\u003eBPCA\u003c/b\u003e and 1, 4-dioxane molecule allowed the sensor as portable chips to respond 1, 4-dioxane vapor with good selectivity over other common VOCs at room temperature. Also, the sensing mechanism based on the 1, 4-dioxane-induced keto-enol tautomerization of the phthalazine moiety was found and supported by DFT calculations.\u003c/p\u003e","manuscriptTitle":"Sensor with strong solid emission for fluorescence colormetric detection of 1, 4-dioxane in Water and vapor based on the Keto-Enol isomerisation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-01-15 11:22:05","doi":"10.21203/rs.3.rs-5824424/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-01-29T13:52:17+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-01-29T10:27:30+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-01-28T22:22:32+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"59358401926034716047744490065593624913","date":"2025-01-23T15:04:23+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"166355606576075034878105188285548461530","date":"2025-01-23T14:15:29+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-01-23T14:03:25+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-01-14T08:25:08+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-01-14T08:24:33+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Fluorescence","date":"2025-01-14T06:02:12+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-fluorescence","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jofl","sideBox":"Learn more about [Journal of Fluorescence](https://www.springer.com/journal/10895)","snPcode":"10895","submissionUrl":"https://submission.nature.com/new-submission/10895/3","title":"Journal of Fluorescence","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"6068db03-c6b4-42d3-bfab-6cc193a19225","owner":[],"postedDate":"January 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-05-19T16:01:16+00:00","versionOfRecord":{"articleIdentity":"rs-5824424","link":"https://doi.org/10.1007/s10895-025-04296-w","journal":{"identity":"journal-of-fluorescence","isVorOnly":false,"title":"Journal of Fluorescence"},"publishedOn":"2025-05-16 15:57:45","publishedOnDateReadable":"May 16th, 2025"},"versionCreatedAt":"2025-01-15 11:22:05","video":"","vorDoi":"10.1007/s10895-025-04296-w","vorDoiUrl":"https://doi.org/10.1007/s10895-025-04296-w","workflowStages":[]},"version":"v1","identity":"rs-5824424","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5824424","identity":"rs-5824424","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}