posted on 2023-01-03, 08:20authored byJunyi Zeng, Caiping Ding, Liang Chen, Bing Yang, Ming Li, Xiaoyuan Wang, Fengmei Su, Chuntai Liu, Youju Huang
Most enzyme catalysts are unable to achieve effective
oxidation
resistance because of the monotonous mimicking function or production
of secondary reactive oxygen species (ROS). Herein, the Au@Cu2O heterostructure with multienzyme-like activities is deigned,
which has significantly improved antioxidant capacity compared with
pure Cu2O for the scavenging of highly cell-damaging secondary
ROS, i.e.,·OH. Experiments and theoretical calculations show
that the heterostructure exhibits a built-in electric field and lattice
mismatch at the metal–semiconductor interface, which facilitate
to generate abundant oxygen vacancies, redox couples, and surface
electron deficiency. On the one hand, the presence of rich oxygen
vacancies and redox couple can enhance the adsorption and activation
of oxygen-containing ROS (including O2·– and H2O2). On the other
hand, the electron transfer between the electron-deficient Au@Cu2O surface and electron donor would promote peroxide-like activity
and avoid producing ·OH. Importantly, endogenous ·OH could
be eliminated in both acidic and neutral conditions, which is no longer
limited by the volatile physiological environment. Therefore, Au@Cu2O can simulate superoxide dismutase (SOD), catalase (CAT),
peroxidase (POD), and glutathione peroxidase (GPx) to form a complete
antioxidant system. The deigned nanoenzyme is explored in the real
sample world such as A549 cells and zebrafish. This work provides
theoretical and practical strategies for the construction of a complete
antioxidant enzyme system.