A Near-Infrared Fluorescent Probe with Large Stokes Shift for Sensitive Detection of Hydrogen Sulfide in Environmental Water, Food Spoilage, and Biological Systems

Hydrogen sulfide (H₂S) is an important endogenous gas transmitter that plays a critical role in various physiological and pathological processes and can also cause a negative impact on foodstuffs. In this study, we designed and synthesized a simple, easily available, high-yield, and low-cost near-infrared (λ_em = 710 nm) fluorescent probe, DEM-H₂S, with a substantial Stokes shift (205 nm) for the detection of H₂S. DEM-H₂S features high selectivity and sensitivity (LOD = 80 nM) toward H₂S, accompanied by a noticeable color change. Upon interaction with H₂S, DEM-H₂S exhibits a restored ICT (Intramolecular Charge Transfer) process, thereby manifesting near-infrared fluorescence. DEM-H₂S has been successfully utilized to detect H₂S in actual water samples and to monitor the spoilage of food items, such as pork, shrimp, and eggs. Furthermore, DEM-H₂S enables the imaging of endogenous and exogenous H₂S in living MCF-7 cells and zebrafish. Hence, DEM-H₂S provides an attractive method for the detection of H₂S in environmental, food, and biological systems, holding potential value in physiological and pathological research.