▎ 摘　　要

NOVELTY - Cerium oxide-reduced graphene oxide nanocomposites having diverse biological enzyme-mimicking activity, comprises graphene oxide as carrier and nano cerium oxide particle supported on the surface of the graphene oxide carrier in situ. USE - The cerium oxide-reduced graphene oxide nanocomposite is useful for enzyme-linked immunoassay, sterilization and antiinflammatory, cancer treatment and antioxidant protection fields (claimed). ADVANTAGE - The cerium oxide-reduced graphene oxide nanocomposite: regulates oxygen-containing functional groups on the surface to improve the superoxide dismutase mimetic activity of graphene oxide and at the same time endow graphene oxide with catalase mimetic activity of antioxidant protection compared to pure graphene oxide. DETAILED DESCRIPTION - Cerium oxide-reduced graphene oxide nanocomposites having diverse biological enzyme-mimicking activity, comprises graphene oxide as carrier and nano cerium oxide (CeO2-x) particle supported on the surface of the graphene oxide carrier in situ. x = 0-0.5. An INDEPENDENT CLAIM is also included for preparing cerium oxide-reduced graphene oxide nanocomposites, comprises (i) dispersing graphene oxide in water to prepare graphene oxide dispersion having concentration of 3-10 mg/ml, (ii) uniformly mixing the graphene oxide dispersion liquid obtained in step (i) and 0.5-1.5 M cerium nitrate aqueous solution in a volume ratio of 1.5-2.5:1 to obtain mixed solution, (iii) adjusting the pH of the mixed solution in step (ii) to 7.4-10 with 0.5-1 M ammonium nitrate aqueous solution, and (iv) reacting the pH-adjusted mixed solution at room temperature for 24-48 hours, reacting, drying the reaction product to obtain cerium oxide-reduced graphene oxide nanocomposite.