A tri-site fluorescent probe for simultaneous sensing of hydrogen sulfide and glutathione and its bioimaging applications.

Hydrogen sulfide (H2S) and biothiol molecules, such as glutathione (GSH), cysteine (Cys), and homocysteine (Hcy), play an important role in biology. However, understanding the complicated relationship between H2S and biothiols remains an enormous challenge owing to the difficulty in sensing H2S and biothiols simultaneously. Therefore, the development of probes for detecting H2S and biothiols is of great importance in biological science. In this work, we reported a novel fluorescent probe for the sensitive and selective detection of H2S and glutathione (GSH) simultaneously in different buffer solutions. The key design principle is based on a coumarin as the fluorophore structuring a fluorescent probe with three potential sites which could react with H2S and biothiols. This probe displays a rapid response with highly sensitive and selective detection of H2S and GSH (the detection limit of 75 nM and 280 nM, respectively). Moreover, with the assistance of a confocal fluorescence microscope, we demonstrated that the probe can be successfully applied for imaging H2S and GSH in MCF-7 cells.