Design And Sensing Properties Of Several Reaction-based Flurescent Probes

Fluoremetric method has been widely used in biological, chemical and environment, due to its simple, reproducible, high sensitivity, selectivity, and good biocompatibility. With the development and demand of science technology, the reaction-based fluorescent probes attracted more and more researchers, because of its specific seletivity and high sensitivity.In this thesis, we designed and synthesized three reation-based fluorescent probes, and studied their potential applications. The main resarch work is as follows:(1) We have presented a readily available probe P1, which consists of a1,3,3-trimethyl-3H-indolium hemicyanine dye as the chromophore and a tert-butyldiphenylsilyl (TBDPS) group as the specific reaction site for F-. This probe was found to be a new promising dual colorimetric and fluorescent sensor for F-. This probe shows high selectivity and sensitivity for F-, and is able to detect F-rapidly in aqueous solution with distinct colour and fluorescent signal changes within a few minutes. The detection limit of this sensor for F-was found to be0.125ppm, which is much lower than the level of the drinking water standard (4ppm) by EPA. We also showed that the easy-to-prepare test paper based on this chemodosimeter provided a convenient method for practical detection of F-in water.(2) We chose ESIPT dye4’-dimethylamino-3-hydroxyflavone and the thiolysis of dinitrophenylether approach to construct a new probe P2. This new probe can be easily prepared and works effectivty at physiological pH and in biological serum samples, showing fast responses with distinct color changes, high selectivity and sensitivity for H2S. It provided a new very promising dual colorimetric and fluorescent sensor for rapid detection of hydrogen sulfide and thus has potential in biological applications.(3) The ESIPT dye4’-dimethylamino-3-hydroxyflavone was further used as the fluorophore in the third part work, and acrylate was used as a reaction site to detect cys-teine (Cys). A new probe P3was prepared. Importantly, it works at physiological pH and is visible light excitable, and shows a rapid detection process, with high selectivity and sensitivity for Cys over Hcy, GSH and other amino acids and anions. In addition, it is able to detect Cys in living cells, thus making this new probe a very promising fluo-rescent sensor for Cys.