Blue Light-Gated Reversible Silver Nanozyme Reaction Networks that Achieve Life-like Adaptivity

Life is preserved by complex enzymatic reaction systems. Inspired by life, here we report on the first example to fabricate blue light-gated reversible silver nanozyme reaction networks that achieve life-like adaptivity. Upon blue light excitation, silver nanoparticles (AgNPs) display oxidase-like activity in the presence of Cl– as a cofactor. The addition of Cl– promotes the separation between hot holes and electrons that are generated by excited-state surface plasmon of AgNPs, inducing the generation of highly reactive hydroxyl and superoxide anion radicals. They oxidize colorless 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt (ABTS) to yield green ABTS radicals (ABTS•+). It is shown that ABTS•+ is able to be reduced by AgNPs to regenerate ABTS when the blue light is turned off, and the reaction system returns to its initial state, which is the typical feature of the artificial adaptive system. The dynamic process of the adaptive system is tunable by changing the concentrations of AgNPs and Cl–, and it possesses excellent recyclable performance, which can be repeated at least six times. Overall, the silver nanozyme reaction networks are capable of responding to blue light stimuli and renewing by recycling to the initial state without blue light irradiation.