Probing the Intracellular Dynamics of Nitric Oxide and Hydrogen Sulfide Using an Activatable NIR II Fluorescence Reporter

Understanding the complex interplay among gasotransmitters is of great significance but remains technically challenging. In this study, we present the design and synthesis of a dually responsive BOD-NH-SC reporter for probing the dynamic and alternating existence of NO and H₂ S in living cells. This designed reporter can repeatedly cycle S-nitrosation and transnitrosation reactions when successively treated with NO and H₂ S, thus affording the interchange of NIR fluorescence at 645 nm (NO) and NIR II fluorescence at 936 nm (H₂ S). In light of this unique fluorescence alternation between two colors, we synthesized water-soluble BOD-NH-SC dots to visualize the intracellular dynamics of NO and H₂ S. These molecular probes thus provide a toolbox to elucidate the interplaying roles of NO and H₂ S in the complex interaction networks of various signal transduction pathways.