Dual-organelle localizing fluorescent probe for selective hydrogen sulfide imaging in mitochondria and lysosomes.

Hydrogen sulfide (H₂S) is a crucial gaseous signaling molecule implicated in a wide range of physiological and pathological processes. Accordingly, a fluorescent probe (INS) has been designed and synthesized for selective detection of H₂S in living cells. Notably, H₂S triggers a specific nucleophilic reaction with INS, distinguishing it from other potential interfering analytes and conferring exceptional selectivity. The probe exhibits a pronounced fluorescence enhancement upon reaction with H₂S. Owing to its remarkable properties-including full water solubility, a low detection limit of 30.1 nM, excellent specificity, a large Stokes shift of 130 nm, a strong linear fluorescence response, and stable emission over a broad pH range (pH 5-12)-INS is ideally suited for the detection of H₂S in complex biological samples. Cellular imaging experiments further demonstrate that INS possesses high-contrast imaging capabilities and excellent membrane permeability, enabling effective visualization of intracellular H₂S. Moreover, INS displays organelle-targeting properties, with the ability to localize selectively to both lysosomes and mitochondria. Taken together, these outstanding features position INS as a promising and versatile fluorescent probe for sensitive and selective detection of H₂S in living cells.