Surface-Engineered Selenium Nanozymes for Food Safety: Photoregulated Catalysis, Multimodal Antibacterial Mechanisms, and Emerging Applications in Food Processing, Packaging, and Biosensing.

Selenium nanoparticles (SeNPs) are increasingly recognized as promising nanozymes for food safety because they combine enzyme-mimetic catalytic activity, broad-spectrum antimicrobial effects, and relatively favorable biocompatibility. However, current understanding remains fragmented across materials science, microbiology, and food application research, and a critical synthesis focused on their food-system relevance is still lacking. This review examines how surface engineering and photoactivation are transforming SeNPs from general antimicrobial nanomaterials into multifunctional platforms for food-related use. We summarize recent advances in their photodynamic and photocatalytic properties, antibacterial and antibiofilm activities, mechanistic basis, and applications in food packaging, food-processing environments, and biosensing. Recent studies show that ligand design plays a central role in determining colloidal stability, bacterial affinity, visible-light responsiveness, catalytic efficiency, and sensing capability. Mechanistically, Se nanozymes act not only through oxidase-like catalysis and reactive oxygen species generation, but also through membrane disruption, metabolic collapse, extracellular DNA degradation, quorum-sensing interference, and, in advanced systems, ferroptosis-like lipid peroxidation. These developments have expanded the potential of SeNPs from microbial control and biofilm eradication to food preservation, process-water disinfection, contaminant removal, and rapid detection of food-relevant analytes. Key challenges remain in standardizing synthesis, clarifying structure-activity relationships, validating performance in real food matrices, and establishing long-term safety, recovery, and regulatory feasibility. A more mechanism-oriented and application-driven framework will be essential for translating Se nanozymes into robust and sustainable food safety technologies.