An electronic equilibrium strategy to drive the design of reversible fluorescent probes for sulfur dioxide and formaldehyde

residues in Chinese herbal medicines and FA in cosmetic products. Importantly, encryption ink based on the irreversible nature of RE-A and the reversible characteristics of RE-D enables advanced anti-counterfeiting applications. Overall, this study not only establishes a pioneering design strategy for the rational design of reversible fluorescent probes, but also expands their applications in bioimaging, analytical detection, and smart materials.