Cobalt-Doped CeO2 Nanozyme with Peroxidase-Like Activity for Broad-Spectrum and Recyclable Degradation of Aflatoxins

Abstract Aflatoxins (AFs) contamination in the food chain poses a serious health threat, and current degradation strategies are limited by insufficient efficiency and stability. We developed a series of cobalt-doped CeO2 (Co@CeO2) nanozymes via a one-step hydrothermal method. The optimized nanozyme (Co-to-CeO2 mass ratio of 2:1) exhibited remarkable peroxidase-like activity, enabling efficient broad-spectrum degradation of aflatoxin B1, G1, and M1 under mild conditions, with removal efficiencies exceeding 90% in aqueous solution and approximately 80% in spiked edible oil samples. Density functional theory calculations and experimental characterization revealed that the enhanced catalytic performance originates from optimized electronic structure, abundant oxygen vacancies, and sustained reactive oxygen species generation. Notably, the nanozyme maintained over 80% degradation efficiency over six consecutive cycles, demonstrating excellent reusability. ECOSAR predictions suggested that the degradation products had reduced aquatic toxicity compared to the parent AFs. This work provides a sustainable nanozyme strategy for mycotoxin detoxification in food matrices.