A Bioinspired Single‐Atom Fe Nanozyme with Excellent Laccase‐Like Activity for Efficient Aflatoxin B1 Removal

Abstract The applications of natural laccases are greatly restricted because of their drawbacks like poor biostability, high costs, and low recovery efficiency. M/NC single atom nanozymes (M/NC SAzymes) are presenting as great substitutes due to their superior enzyme‐like activity, excellent selectivity and high stability. In this work, inspired by the catalytic active center of natural enzyme, a biomimetic Fe/NC SAzyme (Fe‐SAzyme) with O2‐Fe‐N4 coordination is successfully developed, exhibiting excellent laccase‐like activity. Compared with their natural counterpart, Fe‐SAzyme has shown superior catalytic efficiency and excellent stability under a wide range of pH (3.0–9.0), temperature (4–80 °C) and NaCl strength (0–300 mm). Interestingly, density functional theory (DFT) calculations reveal that the high catalytic performance is attributed to the activation of O2 by O2‐Fe‐N4 sites, which weakened the O─O bonds in the oxygen‐to‐water oxidation pathway. Furthermore, Fe‐SAzyme is successfully applied for efficient aflatoxin B1 removal based on its robust laccase‐like catalytic activity. This work provides a strategy for the rational design of laccase‐like SAzymes, and the proposed catalytic mechanism will help to understand the coordination environment effect of SAzymes on laccase‐like catalytic processes.