Development of a novel H2S and GSH detection cocktail for fluorescence imaging

Abstract

Hydrogen sulfide (H₂S) and reduced glutathione (GSH), which basically represent the two terminals of the reactivity order of small-molecular biothiols, are also the most intriguing signal molecules from this family, and their simultaneous detection is challenging but of great importance to clarify their physiopathology. Herein, we reported a borondipyrromethene (BODIPY) derivative (probe ZS2) equipped with a o-formylchalcone moiety for the simultaneous detection of H₂S and GSH in bio-samples. Due to favorable steric and electronic effects, ZS2 can selectively react with H₂S and GSH, accompanied by dramatic fluorescence intensity enhancement. When ZS2 is used in combination with our previously reported H₂S-specific probe ZS1, the simultaneous and discriminative detection of the highest reactive H₂S and the lowest reactive GSH can be realized. As a proof of concept, this detection cocktail has been applied for the quantification of endogenous H₂S and GSH in fresh rat plasma, and for their imaging in live cells. Moreover, ZS2 also features a bioorthogonal module which is readily transformed to organelle-specific functionalities. Facilitated by this module, a mitochondria-targeting version, ZS3, was straightforwardly prepared which realized the simultaneous visualization of H₂S and GSH localized in the mitochondria.