A Holistically Engineered Laccase Nanozyme With Enhanced Activity for Phenolic Compound Removal

To achieve high catalytic activity in laccase-mimicking nanozymes, it is essential to accurately replicate the enzyme's active catalytic center and ensure effective transport of substrates and oxygen. To address this challenge, this work presents a holistic biomimetic strategy based on the natural laccase catalytic process, designing a novel nanozyme Cu-Cys@PCN-222(Cu/Fe). In this nanozyme, the incorporation of Cys and the FeTCPP into the PCN-222 framework achieves the biomimicry of the substrate binding pocket and oxygen-carrying hydrophobic sites, respectively. These two key components enables efficient pollutant enrichment and enhances dissolved oxygen capture and transport. Finally, Cys and TCPP within the PCN-222 framework through the coordination with copper constructed the CuN₄(OH₂)/Cu-S unsaturated copper clusters. This structure imitates the asymmetric coordination structure of the natural laccase active center, achieving highly efficient catalysis of substrate molecules. The synergy factor confirms the synergistic interaction among the three biomimetic functions, and this synergistic architecture promotes a highly efficient catalytic cycle, endowing the nanozyme with 2.2-fold higher activity than natural laccase, as well as excellent structural stability and broad substrate universality. Furthermore, the degradation mechanism and intermediate product evolution were systematically investigated. This work establishes a generalizable paradigm for designing high-performance biomimetic catalysts via the holistic biomimetic strategy.