Self-Assembled Activatable Probes to Monitor Interactive Dynamics of Intracellular Nitric Oxide and Hydrogen Sulfide.

The increasing understanding of the intricate relationship between two crucial gasotransmitters nitric oxide (NO) and hydrogen sulfide (H 2 S) in biological actions has generated significant interest. However, comprehensive monitoring of the dynamic fluctuations of endogenous NO and H 2 S remains a challenge. In this study, we have designed an innovative aggregation-induced reporter SAB-NH-SC with enhanced responsiveness to H 2 S for visualizing the fluctuations of intracellular NO and H 2 S. This probe leverages the hydrophilic properties of the pyridinium salt derivative, which can rapidly self-assemble into positively charged nanoparticles under physiological conditions, avoiding the introduction of organic solvents or tedious preparations. Notably, the reporter can repeatedly cycle S-nitrosation and SNO-transnitrosation reactions when successively treated with NO and H 2 S. Consequently, fluorescence alternation at 751 (H 2 S) and 639 nm (NO) facilitates the dynamic visualization of the alternating presence of H 2 S and NO within cells. This dynamic and reversible probe holds immense potential for unraveling the intricate interactions between NO and H 2 S in a complex network of biological applications.