Assembly of indole fluorophore in situ for hydrogen sulfide signaling through substrate triggered intramolecular reduction-cyclization cascade: a sensitive and selective probe in aqueous solution

A novel probe containing the azide-coumarin-aldehyde triad (S1) for hydrogen sulfide (H2S) was developed. The fluorophore for signaling is assembled in situ through a H2S triggered intramolecular reduction-cyclization cascade, and has a concomitant 10-fold enhancement of the fluorescent intensity at 520 nm. Fluorescence imaging of H2S in living cells proved its potential for biological application.