Rapidly responsive and highly selective NIR fluorescent probe for detecting hydrogen sulfide in food samples and living cells

Hydrogen sulfide (H 2 S) is a pungent gas that is one of the key mediators of signal transduction in biological systems, and its presence is related to the freshness of some protein foods. Using phenothiazine derivatives as fluorophores and 2, 4-dinitrobenzene sulfonate (DNBS) fragments as reaction groups, a near-infrared (NIR) probe WX-HS for H 2 S identification was designed. With the addition of H 2 S, WX-HS appeared a strong fluorescence signal at 660 nm with short reaction time (90 s) and high sensitivity, and fluorescence state change from non-fluorescent to orange-red. In addition, WX-HS could effectively detect H 2 S produced during food oxidation. Based on its low cytotoxicity, the WX-HS probe further enabled the detection and imaging of H 2 S in A549 cells.