Using Wool Keratin Derived Metallo‐Nanozymes as a Robust Antioxidant Catalyst to Scavenge Reactive Oxygen Species Generated by Smoking

Self‐assembled nanostructures based on biomolecules (e.g., proteins and amino acids) and metal ions have promising applications in mimicking the nanostructure, properties, and functions of natural enzymes. Herein, a metal ion‐mediated self‐assembly method for constructing catalytically active Cu‐wool‐keratin (CuWK) two‐dimensional nanozymes is presented. Specifically, by introducing copper ions as abiological cofactors, WK can serve as a protein scaffold to design and create Cu catalytic sites. The optimized hybrids with Cu‐WK coordination framework exhibit significant superoxide dismutases‐like activity, catalase‐like activity, and hydroxyl radical scavenging ability. These combined antioxidant activities make CuWK a robust nanozyme to effectively remove various reactive oxygen species (ROS). In this work, the as‐prepared CuWK as a new additive can be integrated into a cigarette filter system to effectively remove the produced ROS from the burning of tobacco. More importantly, the CuWK nanozymes as a critical element can be further utilized to construct a recycling cigarette holder. Therefore, the present work shows that nanozymes with advanced catalytic capabilities can be constructed by self‐assembly of metal ions and proteins, thus facilitating the rational design and discovery of this kind of artificial metalloenzymes. By self‐assembly of wool keratin and metal ions, a novel metallo‐nanozymes with Cu‐protein coordination framework can exhibit superoxide dismutases‐like activity, catalase‐like activity, and hydroxyl radical scavenging ability. These unique antioxidant properties allow us to construct a nanozyme‐incorporated cigarette filter or holder, which can effectively remove different reactive oxygen species from the burning of tobacco.