Iminocoumarin-based red to near-infrared fluorescent turn-on probe with a large Stokes shift for imaging H2S in living cells and animals

The development of organic dye-based fluorescent probes for detection of H2S in living systems has attracted considerable attention in recent years. In this work, a novel tetrahydroquinoxaline iminocoumarin-based red to near-infrared (red-to-NIR) fluorescent probe was developed for detection of H2S. This probe shows a rapid and distinct red-to-NIR fluorescent turn-on detection process for H2S with high selectivity and sensitivity (the detection limit was determined to be as low as 10 nM at physiological pH). In addition, this probe exhibits a remarkable large Stokes shift (128 nm) and low cytotoxicity, and can be applied for imaging H2S in living cells and animals. All these results demonstrated that this new probe is promising for detection of H2S both in vitro and in vivo.