Highly selective turn-on probe for H2S with imaging applications in vitro and in vivo

Abstract

Hydrogen sulfide (H2S) is the third endogenous gaseous signaling molecule, and its distribution affects several biological processes. To clarify the roles of H2S in living systems, the exact determination of H2S in living cells in vivo has become an important issue. Herein, we report a novel pyrene-based fluorescent probe, PyN3, as a H2S turn-on sensor via reduction of azide to amine, which subsequently undergoes self-immolation through intramolecular 1,6-elimination of the rho-aminobenzyl moiety, releasing 1-aminopyrene and leading to the recovery of fluorescence intensity. With its high sensitivity, good selectivity, and low cytotoxicity, PyN3 was able to recognize both exogenous and endogenously produced H2S in biological systems. In contrast to the traditional azide-based H2S probes, PyN3 shows efficient and effective selectivity to H2S at biological pH ranges. Because of these promising properties, PyN3 is an excellent probe for visualizing endogenous H2S in vitro and in vivo.