A dual responsive fluorescent probe for selective detection of cysteine and bisulfite and its application in bioimaging

A coumarin-based dual responsive fluorescent probe with a simple structure was developed for the detection of Cys and HSO3-. Under simulated physiological conditions, Cou-F displayed an on-off fluorescence response to Cys at 521 nm and an off-on fluorescence response to HSO3- at 500 nm. Furthermore, Cou-F had the advantages of high sensitivity, strong specificity and rapid response. The detection limits of Cou-F toward Cys and HSO3- were 0.54 μM and 0.65 μM, respectively. Cou-F enabled high selective responses to Cys and HSO3- over other biologically related species. The response times of Cou-F toward Cys and HSO3- were 80 s and 100 s. The fluorescence imaging of Cys and HSO3- was achieved in living RAW246.7 cells.