Novel near-infrared spectroscopic probe for visualizing hydrogen sulfide in lysosomes

Considering the scarcity of hydrogen sulfide (H2S) probes with subcellular organelle targeting, especially probes with near-infrared (NIR) emission wavelengths fluorophores, our group has been working to overcome this problem and looking forward to providing potential practical tools for exploring the relationship between the physiology and pathology of H2S at subcellular level. In this paper, a novel colorimetric and NIR fluorescent probe SHCy-H2S for the specific detection of H2S in lysosome over other biological thiols was designed and synthesized. The xanthene-benzothiozolium fluorophore was chosen to provide fluorescence emission maxima over 735 nm, and 2,4-dinitrophenyl group was chosen as fluorescence quenching group and specific H2S response site. Impressively, SHCy-H2S exhibited high selectivity, fast response and detection limit as low as 0.116 μM for H2S, marked obvious color changes in naked-eye and fluorescence. Specially, SHCy-H2S was capable of specifically imaging endogenous lysosomal hydrogen sulfide, providing a potential tool for exploring the function of H2S at subcellular level.