摘要：Biothiols such as cysteine(Cys),homocysteine(Hcy)and glutathione(GSH)act as critical roles in maintaining biological redox homeostasis,which is crucial for a plenty of physiological and pathological processes.Therefore,the detection of biothiols is very important and beneficial for many applications.Herein,we have designed and developed a new crystal dimethyl 4-(2,4-dinitrophenylsulfonyloxy)pyridine-2,6-dicarboxylate(P)with 2,4-dinitrobenzene-1-sulfonyl(DNBS)pendant for light-up and detection of biothiols(Cys was selected as the analyte model).The fluorescence"off-on"switch is triggered by the cleavage of DNBS unit by the interaction with biothiols via nucleophilic aromatic substitution reaction.The turn-on fluorescent probe exhibited excellent selectivity and sensitivity toward biothiols.