Highly selective near-infrared fluorescent probe with rapid response, remarkable large Stokes shift and bright fluorescence for H2S detection in living cells and animals

The detection of hydrogen sulfide (H2S) in living systems has received considerable attention in recent years. Although many probes have been reported for detection of cellular H2S, the creation of rapid, highly selective and sensitive near-infrared (NIR) probe for in vivo detection of H2S still remains a challenging target. Herein, a novel dicyanoisophorone-based NIR fluorescent turn-on probe for H2S was reported. This probe uses a sulfonamide group for the first time as a selective reaction site for H2S and more importantly, it displays a rapid (<1 min), highly selective and sensitive (detection limit: 6 nM) response for H2S, giving bright NIR fluorescence output (fluorescence enhancement >130-fold) with a remarkable large Stokes shift (221 nm). Moreover, it has low cytotoxicity and can be used for tracking and imaging of H2S in living cells and animals. Overall, this work provided a very promising NIR fluorescent probe with a new reaction site and excellent sensing properties for rapid detection of H2S both in vitro and in vivo.