A new lysosome-targetable fluorescent probe with a large Stokes shift for detection of endogenous hydrogen polysulfides in living cells.

Hydrogen polysulfides (H2Sn, n > 1) influence a variety of important biological functions and activities associated with hydrogen sulfide (H2S). The development of probes for rapid, selective, and sensitive detection of H2Sn still remains a great challenge. Lysosome plays crucial roles in various physiological processes among living cells, which arouse high interest in detecting endogenous lysosome-targetable H2Sn. To the best of our knowledge, there is no lysosome-targetable probe for H2Sn has been reported. In this work, a new lysosome-targetable probe NIPYNF, based on the scaffold of imidazo [1,5-]pyridine, with a large Stokes shift (215 nm), low detection limit (84 nM), fast response time (6 min) and low cytotoxicity was designed and synthesized. Furthermore, NIPYNF was successfully applied into the cell imaging for detection of endogenous lysosome-targetable H2Sn.