Multienzyme-Mimetic Activity of Gold/Cerium Oxide Nanozyme

Redox-active nanozymes offer low-cost controlled synthesis, high stability, and tunable catalytic properties over natural enzymes, which have attracted wide attention in the field of disease diagnosis and treatment. However, the improvement of catalytic activity remains an important challenge for nanozymes. Herein, the Au/CeO₂ nanozymes is developed to achieve enhanced multiple enzyme-mimetic activity. The Au/CeO₂ nanozymes at 5% doping possess best peroxidase-like activity with threefold higher catalytic rate than CeO₂. For catalase-mimic catalysis, the Au/CeO₂ nanozymes at 5% doping also exhibited a 1.5-fold enhanced reaction rate higher than pure CeO₂. The superoxide dismutase (SOD)-like capacity of Au/CeO₂ nanozymes is proportional to Au content. The Au/CeO₂ nanozymes at 10% doping show optimal SOD-like capacity of 60.2 U mg^?1. In vitro experiments validate the regulation ability of intracellular oxidative stress and inflammation. Au/CeO₂ nanozymes can reduce lipopolysaccharide- or H₂O₂-induced oxidative damage by scavenging excess ROS in nerve cell. Therefore, Au/CeO₂ can be used as a promising antioxidant in disease treatment, and the study offers general guidelines for achieving enhanced biocatalytic property through atomic doping.