The Research Of The Fluorescent Chemosensors:Based On Aliphatic Thiols And Zn²⁺ Recognition

In recent years, more and more people realize the importance of environment pollution and human health, develop a series for the detection of human beneficial or harmful species, functional organic molecules for both the environment and medicine, or people’s lives and so vitalsignificance. Fluorescent chemosensors have high selectivity, high sensitivity, easy operation and good reproducibility become the preferred target of many researchers.This paper designed and synthesized two fluorescent chemosensors:based on coumarin hydrazide anion chemosensors (compound1) and s based on benzothiazole cation chemosensors (compound5). The test results show that:compound1in the ultraviolet spectrum of Cu2+with high selectivity, the formation of the measurement than the1:1form complexes,for the metal complexation of compound1, the fluorescence quenching. When complex1-Cu (Ⅱ) coexist with aliphatic thiols and glutathione, the quenching of the fluorescence is recovered, so achieve the detection of aliphatic thiols and glutathione. The solution of complex1-Cu (Ⅱ) that added Cu2+and ethanethiol by cycle, Strong reduction of sulfur hydroxy enable the divalent copper ion reduction to cuprous ions, the solution can be recycled quenching and luminescence. Therefore, this chemosensors can be used as fluorescence switch which can two-way choice of copper ions and thiols. This chemosensor has good selectivity and high sensitivity,can detect thiols and glutathione in the environment.Compound5is a compound of the excited state intramolecular proton transfer (ESIPT). Compound5does not light solution in acetonitrile, for the form of complexation of Zn2+, preventing the process of excited state intramolecular proton transfer (ESIPT), the fluorescence enhancement to about350times. Therefore, show high selectivity and sensitivity of response to Zn2+, to other cations no response and non-luminous. Compound5has a fast response time, sensitivity and selectivity to zinc, can be applied to the detection of Zn2+in environment.