Fluorescent probes for nitric oxide and hydrogen peroxide in cell signaling

Nitric oxide (NO) and hydrogen peroxide (H₂O₂) have emerged as essential small molecules for cellular signal transduction owing largely to their ability to mediate oxidative posttranslational modifications (PTMs). Inventing new ways to track these small, diffusible, and reactive species with spatial and temporal resolution is a key challenge in elucidating their chemistry in living systems. Recent progress in the development of fluorescent probes that respond selectively to NO and H₂O₂ produced at cell signaling levels offers a promising approach to interrogating their physiological production, accumulation, trafficking, and function.