Development of an activatable red emissive fluorescent probe for imaging hydrogen disulfide upregulation in living cells and zebrafish.

As a member of reactive sulfur molecules, hydrogen polysulfide (HS) plays a vital role in cell protection, anti-oxidative stress and regulation of redox signaling. The highly selective and sensitive detection of HS was still challenging due to its special nucleophilic and electrophilic reactivity. By incorporating phenyl 2-(benzoylthio) benzoate into semi-naphthofluorescein, we developed a novel red emissive fluorescent probe SNAFL-HS for the detection of a representative HS (e. g. HS). The addition of HS would rapidly trigger SNAFL-HS to produce significant turn-on fluorescence signal changes at 626 nm with a linear response over a range of 2-30 μM and a detection limit of 16 nM. SNAFL-HS was capable of mapping exogenous and endogenous HS in living cells and zebrafish. Moreover, SNAFL-HS was applied to detect endogenous HS under atorvastatin stimulation. The present study demonstrated that SNAFL-HS potentially served as a promising tool for interrogating HS functions in biological systems.