Fluorescent probes for detection of biothiols based on “aromatic nucleophilic substitution-rearrangement” mechanism

Biothiols,including cysteine(Cys),homocysteine(Hey),and glutathione(GSH) play important roles in physiological processes,and the detection of thiol using fluorescent probes has attracted attention due to their high sensitivity and selectively and invasive on-time imaging.However,the similar structures and reactivity of these biothiols present great challenges for selective detection.This review focused on the the "aromatic nucleophilic substitution-rearrangement(SNAr-rearrangement) mechanism",which provided a powerful tool to design fluorescent probes for the discrimination between biothiols.We classify the fluorescent probes according to types of fluorophores,such as difluoroboron dipyrromethene(BODIPY),nitrobenzoxadiazole(NBD),cyanine,pyronin,naphthalimide,coumarin,and so on.We hope this review will inspire exploration of new fluorescent probes for biothiols and other relevant analytes.