Multienzyme-mimetic nanozym es for food safety detection: Cascade catalytic design, activity regulation, and sensing applications.

Ultrasensitive detection of trace-level hazardous substances (pesticide residues, heavy metals, bacteria, veterinary drugs, food additives, organic pollutants) is critical for food safety. Conventional methods are costly, complex, or insufficiently sensitive in complex matrices. Multienzyme-mimetic nanozymes, integrating peroxidase, oxidase, catalase, superoxide dismutase, and laccase activities, enable self-cascading signal amplification, overcoming the limited versatility of single-activity nanozymes. This review discusses their rational design and activity modulation, emphasizing how internal parameters (size, morphology, composition, surface chemistry) and external conditions (pH, temperature, light) govern catalytic performance and cascade efficiency. Applications for detecting pesticides, heavy metals, bacteria, and food additives in food matrices are highlighted, along with matrix interference mitigation. Key challenges include unclear synergistic mechanisms, poor specificity, and lack of standardized evaluation. Future intelligent, portable, and multiplexed sensing platforms are proposed to bridge laboratory research and on-site deployment.