Cerium Oxide Nanozymes: Exploring Synthesis, Catalytic Activity, and Biomedical Potential

Cerium oxide (CeO₂) nanozymes have emerged as a novel class of nanozyme materials distinguished by their tunable valence states (Ce³⁺/Ce⁴⁺) and abundant surface oxygen vacancies (OVs), demonstrating exceptional chemical stability, cost-effectiveness, and scalable manufacturability. Precise control of reaction temperature or implementation of carrier-mediated crystal growth strategies effectively enhances nanoparticle dispersion and mitigates aggregation. This review systematically summarizes recent advancements in CeO₂ nanozymes: First, it elaborates on cutting-edge synthetic methodologies, encompassing self-supported strategies (calcination, hydrothermal, and sol-gel) and carrier-mediated approaches (small-molecule compounds, macromolecular compounds, and nanomaterials), with comparative analysis of their respective merits and limitations. Second, the catalytic mechanism is comprehensively elucidated, particularly focusing on the modulation of electron transfer kinetics and surface adsorption energies in metal/nonmetal hybrid systems. By optimizing oxygen vacancy concentration to regulate Ce³⁺/Ce⁴⁺ redox cycling dynamics, significant enhancement in redox efficiency and catalytic stability can be achieved, enabling precise enzyme-like activity regulation. Furthermore, the review comprehensively summarizes breakthrough applications in multidimensional biomedical fields, including precision tumor therapy, intelligent antibacterial systems, inflammatory microenvironment regulation, and ultrasensitive biosensing. This work establishes a theoretical framework for structure-activity relationship-guided rational design of high-performance CeO₂ nanozymes and delineates their potential translational applications in precision medicine.