A near-infrared fluorescent probe that can image endogenous hydrogen polysulfides in vivo in tumour-bearing mice.

Hydrogen polysulfides (HS, n > 1), which are important reactive sulfur species, play crucial roles in HS-related bioactivities, including antioxidation, cytoprotection, activation of ion channels, transcription factor functions and tumour suppression. Monitoring HSin vivo is of significant interest for exploring the physiological roles of HS and the exact mechanisms of HS-related diseases. Herein, we conceive a novel near-infrared fluorescent probe, NIR-CPS, that is used to detect HS in living cells and in vivo. With the advantages of high sensitivity, good selectivity and a remarkably large Stokes shift (100 nm), NIR-CPS was successfully applied in visualizing HS in living cells and mice. More importantly, NIR-CPS monitored HS stimulated by lipopolysaccharide in tumour-bearing mice. These results demonstrate that the NIR-CPS probe is a potentially powerful tool for the detection of HSin vivo, thus providing a valuable approach in HS-related medical research.