A novel near-infrared fluorescent probe with large Stokes shift for imagining hydrogen sulfide.

Hydrogen sulfide (H2S) plays an important role in regulating varieties of important physiological and pathological processes. Thus the development of fluorescent probe for the detection of H2S is of great significance and has attracted much attention recently. Herein, we reported a novel near-infrared (NIR) emitting fluorescent probe WFP-PC, which contained a positive charged hemicyanine-based WFP-OH as fluorophore and thiobenzoate unit as a specific reaction site. After treated with H2S, the probe exhibited significant fluorescence enhancement and response time within 4 min and detection limit as low as 0.47 μM, accompanied by color changes from purple to blue. The probe was successfully applied to imaging the exogenous/endogenous H2S in cells and mice, suggesting it could be a promising molecular tool for H2S detection in living systems.