Near-Infrared Fluorescent Probe with a Large Stokes Shift for Detection of Hydrogen Sulfide in Food Spoilage, Living Cells, and Zebrafish.

Hydrogen sulfide (H 2 S) is a significant component of various physiological processes, and it can also cause a negative effect on foodstuffs. In this work, we designed and synthesized an NIR fluorescent turn-on responding probe ( DDM-H 2 S ) with a large Stokes shift (190 nm) for the detection of H 2 S. DDM-H 2 S exhibited high selectivity and sensitivity, obvious color changes, and a fast response time for tracing H 2 S. When DDM-H 2 S reacted with H 2 S, the PET process was eliminated, and the recovered ICT process and NIR fluorescence were observed. Moreover, DDM-H 2 S could image endogenous and exogenous H 2 S in living HeLa cells and zebrafish. What is more, the probe DDM-H 2 S could be deposited easily to test paper strips, which were able to detect the H 2 S gas produced during food spoilage (such as eggs, raw meat, and fishes) by the color of test paper strips changing from pink to purple. Therefore, this work provides a promising approach for monitoring H 2 S in complicated biological systems and practical food samples.