H2S2-triggered off-on fluorescent indicator with endoplasmic reticulum targeting for imaging in cells and zebrafishes

Reactive sulfur species (RSS) play important physiological and pathological roles in biological redox homeostasis, cell signaling and the regulation of metabolism. Recent studies indicate that hydrogen polysulfides (H2Sn) are the actual signal molecules in animal cells. Although H2Sn have been implied to be answered for transcription factors, ion channels, and mediating tumor suppressors, more of their biological effects such as the effect of a specific hydrogen polysulfide in subcellular organelle are still needed to be elaborated. The detection of a specific hydrogen polysulfide (e.g. H2S2) in living systems is essential for investigating their functions but is quite challenging. Herein, we report an off-on fluorescent probe ER-H2S2 with a favorable photophysical property, high specificity, wide linear range and low cytotoxicity via a facile synthesis for the detection of H2S2 endoplasmic reticulum-selectively in living cells and in zebrafish models in vivo, giving an example of the use of fluorescent probes in real-time imaging exogenous and endogenous H2S2 in subcellular organelle during the course of inflammation and anti-inflammation.