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

A new near-infrared (NIR) fluorescent probe WX-HS was designed for the selective detection and imaging of H 2 S. [Display omitted] • A "turn-on" NIR phenothiazine-based fluorescent probe (WX-HS) was prepared. • WX-HS could quickly, selectively and sensitively detect H 2 S with large Stokes shift (220 nm). • WX-HS could be used to detect the freshness of food samples (pork, chicken, beef and fish). • WX-HS also be confirmed could detect exogenous H 2 S in 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. [ABSTRACT FROM AUTHOR]