The unique substitution-cyclization reaction cascade inspired highly selective H2Sn probe development

Researches focused on the chemical biology of endogenous hydrogen polysulfide (H2Sn, n > 1) is rapidly growing since H2Sn potentially playing crucial roles in many physiological activities. Herein, by taking advantage of the unique H2Sn, but not H2S or biothiols, mediated substitution-cyclization reaction cascade, we have developed a novel fluorescent probe, C-HPS, for highly selective detection of H2Sn over H2S or biothiols. Upon addition of H2Sn, C-HPS displayed remarkable fluorescence enhancement (up to 97 folds) at 576 nm with rapid response time (within 6 min) and adequate sensitivity (LOD = 20 nM). Besides, the application of C-HPS to visualize intracellular H2Sn was also demonstrated in living MGC-803 cells.