A fluorescein-based fluorescence probe for the fast detection of thiol

We designed a asymmetric fluorescein-based probe for the detection of thiol using 2,4-dinitrobenzenesulfonyl (DNBS) group as the detection group. The probe shows nonfluorescence when connected with 2,4-dinitrobenzenesulfonyl which destroys the π-conjugation and its fluorescence appears when the probe reacts with thiol.