An isophorone-based far-red emitting ratiometric fluorescent probe for selective sensing and imaging of polysulfides

Recent studies have shown that as members of the reactive sulfur species family and the oxidized forms of H₂S, hydrogen polysulfides (H₂S_n) play important roles in physiological and pathological processes. Therefore, accurate detection of H₂S_n levels in living systems is of great significance. In this study, we report an isophorone-based far-red emitting fluorescent probe (RPHS1) for selective ratiometric sensing and imaging of H₂S_n. RPHS1 shows specific ratiometric response towards H₂S_n with fast reaction rate and low detection limit in aqueous media. Furthermore, confocal fluorescence microscopy experiments demonstrate that RPHS1 can be applied for H₂S_n imaging in living cells.