Recent Advances in Fluorescent Probes for Biothiols

Abstract

Biothiols, including cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), play an important role in life activities, and the fluctuation of their concentrations is closely related to many diseases. Therefore, it is of great importance to detect the content of biothiols. Among all varieties of techniques, the fluorescent probe demonstrates tremendous advantages ascribed to its good sensitivity, high temporal-spatial resolution, noninvasiveness and visualization. Taking advantage of the commonality and differences among the three thiols, namely, the similar reactive groups of sulfhydryl group and amino group, and the different molecular size, nucleophilicity, steric hindrance and intracellular contents, various recognition mechanisms, such as Michael addition, aromatic nucleophilic reaction and concerted addition and cyclization reaction, are all implemented to realize the specific detection of biothiols. The research progress of thiol fluorescent probes in recent three years is reviewed. The fluorescent probes that can selectively respond to biothiols as well as to Cys, Hcy and GSH are systemically analyzed and summarized. The molecular design, recognition mechanism, fluorescence properties and imaging applications are emphasized, and the application of biothiol fluorescent probe on monitoring life activities is preliminary introduced. In addition, a perspective of future development in this area is also presented.