Sensitive and effective imaging of carbon monoxide in living systems with a near-infrared fluorescent probe

CO, a gas molecule that is harmful to living organisms, has a high affinity with hemoglobin, which will cause severe hypoxia. However, in recent years, researchers have discovered that endogenous CO, similar to NO, is one of the messenger molecules, which has a certain regulatory effect in many physiological and pathological processes in the respiratory system, cardiovascular system, and nervous system. Therefore, it is urgent to explore an effective method to monitor the role of CO under physiological and pathological conditions. Herein, we designed and synthesized a near-infrared small-molecule fluorescent probe for the detection of CO in living cells. In this design, a two-site BODIPY dye was introduced as the fluorophore, and the allyl chloroformate part as the CO reactive group. The probe displays excellent sensitivity, selectivity, and a good linear relationship to CO. Furthermore, it shows good biocompatibility and low cytotoxicity. This probe has been successfully applied to the detection of CO in a variety of cells. The developed fluorescent probe can serve as a potential molecular imaging tool for in vivo imaging and detection of CO.