Hydrogen sulfide mediated cascade reaction forming an iminocoumarin: applications in fluorescent probe development and live-cell imaging

The study on a fluorescent probe that undergoes a H2S mediated cascade reaction to form an iminocoumarin fluorophore is reported. The probe features better water solubility and fast sensing time (t1/2 = 6.1 min and response time = 24 min) as key advances compared to the reported probe that works on a similar mechanism. The sensing mechanism of the probe was demonstrated by mass spectrometric, HPLC titration and FT-IR titration methods. H2S sensing by the probe was characterized by a 31-fold fluorescence enhancement and alimit of detection of 169 nM. Application of the probe was demonstrated by imaging of H2S in live cells.