A hemicyanine dye fluorescent probe for the detection of H2S in food spoilage and living cells.

Hydrogen sulphide (H2S) is a crucial reactive small molecule with important physiological functions in the human body. Dysregulation of H2S in living organisms is associated with various diseases. Moreover, H2S serves as a critical biochemical indicator for evaluating food quality and decomposition status, which highlights the critical need for its detection. Here, we present a hemicyanine dye fluorescent probe, HT-EA, designed for the selective detection of H2S via the Michael addition reaction. HT-EA exhibited a relatively rapid response toward H₂S (reaching equilibrium within 4 min) and an obvious fluorescence intensity decrease at 580 nm was observed with a detection limit of 1 μM. Concurrently, the solution color underwent a distinct transition from light orange to colorless, observable by the naked eye. We successfully applied HT-EA to test strips for real-time monitoring of H2S gas released during food spoilage to determine the freshness of food. Furthermore, HT-EA demonstrated the ability in the detection of H2S in living cells.