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

Hydrogen sulfide (H2S) 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-H2S) with a large Stokes shift (190 nm) for the detection of H2S. DDM-H2S exhibited high selectivity and sensitivity, obvious color changes, and a fast response time for tracing H2S. When DDM-H2S reacted with H2S, the PET process was eliminated, and the recovered ICT process and NIR fluorescence were observed. Moreover, DDM-H2S could image endogenous and exogenous H2S in living HeLa cells and zebrafish. What is more, the probe DDM-H2S could be deposited easily to test paper strips, which were able to detect the H2S 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 H2S in complicated biological systems and practical food samples.