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

Highlights: • A novel lysosome-targetable probe NIPYNF was reported. • NIPYNF could discriminate H₂S_n over other analytes with high sensitivity, a low detection limit and a large Stokes shift. • NIPYNF could detect the endogenous H₂S_n in lysosome of living cells. -- Abstract: Hydrogen polysulfides (H₂S_n, 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 H₂S_n 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 H₂S_n. To the best of our knowledge, there is no lysosome-targetable probe for H₂S_n 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 H₂S_n.