Umbelliferone-Based Fluorescent Probe for Selective Recognition of Hydrogen Sulfide and Its Bioimaging in Living Cells and Zebrafish.

Hydrogen sulfide (H₂S) plays a crucial role in a variety of physiological and pathological processes, similar to other gaseous signaling molecules. The significant pathophysiological functions of H₂S have sparked a great deal of interest in the creation of fluorescent probes for H₂S monitoring and imaging. Using 3-cyanoumbelliferone as the push–pull fluorophore and a dinitrophenyl substituent as the response site, herein we developed a umbelliferone-based fluorescent probe 1 for H₂S, which exhibited a remarkable turn-on fluorescence response with a low detection limit (79.8 nM), high sensitivity and selectivity. The H₂S-sensing mechanism could be attributed to the cleavage of the ether bond between the dinitrophenyl group and the umbelliferone, leading to the recovery of an intermolecular charge transfer (ICT) process. Moreover, the probe had negligible cytotoxicity and good cell membrane permeability, which was successfully applied to image H₂S in MCF-7 cells and zebrafish. [ABSTRACT FROM AUTHOR]