Biomimetically Engineering Valency in Copper Aerogel Toward Efficient Laccase-Mimicking Nanozyme

Developing nanozymes with high intrinsic activity to bridge the gap with natural enzymes has received unremitting attention. In this study, inspired by the copper active center for natural laccase and the multivalent characteristic of Cu, the valence state of Cu-based aerogel is modulated via adjusting the reductant usage for mimicking laccase. The laccase-mimicking activity is well-tailored via valence state manipulation, and theoretical calculations unveil the mechanism that the Cu⁰ and Cu^I species enhance the substrate adsorption capability and the Cu^II species are paramount to lowering the activation barrier synergistically. Heterogeneous metals are further incorporated to promote the valency-conversion of Cu and biomimetic electron transfer, conferring the constructed CuPt_7.5% aerogel nanozyme with an ultralow detectable limit of 1 nm for phenolic pollutants. This work highlights the multivalence of Cu on laccase-mimicking activity and provides insights into the underlying catalytic mechanism, shedding light on the rational design of high-performance nanozymes for practical application.