A red to near-infrared fluorescent probe featuring a super large Stokes shift for light-up detection of endogenous H2S.

Abstract In this work, a new reaction-based red to near-infrared (NIR) fluorescent turn-on probe for H 2 S was developed. This probe uses a readily prepared dicyanoisophorone as the fluorophore and a 2, 4-dinitrobenzenether with an ortho -aldehyde group as the reaction site. Upon addition of H 2 S, a fast nucleophilic addition of H 2 S to the aldehyde group and a following efficient intramolecular thiolysis of dinitrophenyl ether occurred, which leads to release the fluorophore and give a rapid NIR fluorescence turn-on response for H 2 S with a super large Stokes shift (244 nm). The fluorescence enhancement was found up to 105-fold and the detection limit was determined to be as low as 42 nM. Importantly, this probe shows high selectivity and sensitivity for H 2 S without interference from biothiols. Furthermore, NIR fluorescent imaging of exogenous and endogenous H 2 S in living cells with this probe was also successfully applied. All the results indicate that this probe is excellent and highly valuable. Graphical abstract Image 1 Highlights • A new dicyanoisophorone-based NIR fluorescent probe for H 2 S was reported. • This probe is highly selective and sensitive for H 2 S. • This probe shows a rapid NIR fluorescence turn-on response for H 2 S with a super large Stokes shift (244 nm). • This probe can be used to detect exogenous and endogenous H 2 S in living cells. [ABSTRACT FROM AUTHOR]