A “turn-on” fluorescent sensor based on three-component covalent organic framework for trace water detection

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 311; p. 123978
• Main Authors: Zou, Liangmei, Li, Mengyao, Wang, Xinyi, Ye, Meiling, Chen, Lili, Wang, Li, Song, Yonghai
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 15.04.2024
• Subjects: Aggregation induced emission; Covalent organic framework; Fluorescence sensor; Intramolecular charge transfer; Trace water; Trace water; Covalent organic framework; Fluorescence sensor; Aggregation induced emission; Intramolecular charge transfer
• ISSN: 1386-1425; 1873-3557
• DOI: 10.1016/j.saa.2024.123978

[Display omitted] •Five COFs with aggregation-induced emission characteristics were synthesized.•The response sensitivity was adjusted by adjusting the component ratio.•The first COF based fluorescence sensor for ultra-trace water detection.•Test strips were prepared for visual detection of trace water in the field. Trace amount of H2O is difficult to eliminate in laboratory environments and chemical industries as impurities. In some chemical reactions, trace amount of H2O can alter final reaction products, yield, and selectivity. So, the detection of trace H2O is very important. Herein, a series of TFPT[X]-BMTH- covalent organic frameworks (COFs) (X = 0, 33, 50, 67, 100 %) with intramolecular charge transfer effect (ICT) and aggregate-induced emission (AIE) characteristics were synthesized by amino-aldehyde condensation reaction between 2,5-bis(2-methoxyethoxy)terephthalohydrazide (BMTH)/ 1,3,5-tris(p-formylphenyl)benzene (TFPB) and 4,4′,4′'-(1,3,5-triazine-2,4,6-triyl)tribenzaldehyde (TFPT). By changing TFPT’ content in TFPT[X]-BMTH-COFs, the ICT and AIE of TFPT[X]-BMTH-COFs can be controlled, and accordingly the response to trace H2O can be adjusted. A H2O sensor based on TFPT[67]-BMTH-COF with a wide linear range from 0 wt% to 0.5 wt% was developed and the detection limit was 0.00007 wt%. In addition, a portable fluorescent test paper based on TFPT[67]-BMTH-COF for visual detection of trace H2O in honey samples and salt was constructed. This work has important guiding significance for the development of fluorescent probes for the visual detection of trace water.