A novel benzothiazole-based fluorescent probe for cysteine detection and its application on test paper and in living cells

A novel simple and readily synthesized turn-on fluorescent probe 4-(benzo[d]thiazol-2-yl)-1,3-phenylene bis(2-chloroacetate) (BPBC) for cysteine (Cys) was reported. This probe was designed based on an excited-state intramolecular proton transfer (ESIPT) dye: benzothiazole, and two chloroacetate groups present in benzothiazole as the reaction sites for Cys. It shows high selectivity and sensitivity for Cys over other amino acids including the similar structured homocysteine (Hcy) and glutathione (GSH). In addition, probe BPBC was successfully applied to bioimage intracellular Cys in living cells with low cytotoxicity. More importantly, a paper test strip system was developed with probe BPBC for Cys detection conveniently. [Display omitted] •A novel selective turn-on fluorescence probe for cysteine with high selectivity was developed.•This probe has very simple structure but possesses readily available.•This probe can be used conveniently for detecting Cys with paper test strips.•This probe has been used for detection of Cys in living cells successfully.