High selective distinguishable detection GSH and H2S based on steric configuration of molecular in Vivo

Due to the intimate relationship of glutathione (GSH) and H2S in redox biology, it is crucial to establish a convenient synchronous detection method for them. A modified coumarin-based dye with two reaction sites was designed. The alpha,beta-unsaturated ketone was adjacent to benzaldehyde, which constructed a steric - resistive reaction model. GSH with long chain could react with both the alpha,beta-unsaturated ketone and the aldehyde group of the molecule, thus induced a green fluorescent emission. H2S with compact structure firstly reacted with alpha,beta-unsaturated ketone, then the sulfhydryl group triggered secondary nucleophilic-cyclization with aldehyde to form a five-membered ring conjugating the whole molecule, which made the system give out a yellow fluorescent emission. Thus, high selective distinguishable detection GSH and H2S by two emission channels was realized. Cysteine (Cys) or homocysteine (Hcy) had no positive response to the probe compared with GSH. Also, biological imaging verified that the probe can be used in cell and mice. The result provided a clear idea for the design of multifunctional fluorescent probe.