Hydrogen sulfide (H2S) is a key biosignal molecule in the human body. Endogenous H2S, as a gas delivery and protective agent in the body, is involved in a variety of physiological processes, including mediating vascular tone and neuromodulation. The production of abnormal H2S levels in the body is related to the occurrence of various diseases, so real-time monitoring of H2S in vivo is very important. However, traditional detection methods face enormous challenges in the in vivo detection of H2S owing to its high volatility and rapid catabolism. Optical probes developed in recent years with the advantages of high sensitivity, short response time, non-invasive nature and capacity for real-time monitoring can overcome the limitations of traditional detection methods and offer the possibility of real-time monitoring of H2S in cells and in vivo. In addition, the production of high concentrations of H2S is closely related to the formation of colon cancer, and H2S-activated treatment agents have been developed for use in this particular tumor microenvironment, which reduce the toxic side effects of traditional therapy on normal tissues and improves the treatment effect. This review summarizes the recent advances in H2S detection probes in vitro and in vivo, as well as H2S-activated tumor treatment agents.
