Development of an effective H₂S-activatable fluorescent probe for imaging drug-induced living cells

Hydrogen sulfide (H₂S) is a toxic gaseous signaling molecule that plays multiple physiological regulatory roles in both physiological and pathological processes. A novel fluorescent probe, T1, was designed and synthesized for detecting H₂S in biological systems. Based on the ICT mechanism, thiolysis of the 2,4-dinitrophenyl ether group, used as the fluorescence quenching group, occurred after the addition of H₂S, releasing the original fluorescent group, and was accompanied by the recovery of the fluorescence signal (emission peak at 615 nm) with a detection limit of 0.42 μM. Probe T1 displayed low cytotoxicity and excellent ability to recognize exogenous and endogenous H₂S in living cells. It could recognize H₂S produced by LPS-induced cell inflammation, monitor the release of H₂S by the H₂S prodrug ADT-OH in cells, and serve as an anti-counterfeiting dye for printing technology, confirming the reliability of the probe. Therefore, probe T1 can be used as a fast and effective tool for detecting H₂S <i>in vitro</i> and <i>in vivo</i>.