Novel interface-enhanced bimetallic nanozyme-mediated magnetic integrated nanoplatform for integrated prevention and control of pathogenic bacteria.

BACKGROUND: The combination of sensitive detection and instant sterilization of foodborne pathogenic bacteria can provide early warnings for food safety and prevent further bacterial contamination. As functional nanomaterials with enzyme-like catalytic activity, nanozymes have shown significant application potential in the detection and elimination of pathogenic bacteria. However, most nanozymes still face problems such as low catalytic efficiency and a limited ranges of enzymatic reactions in practical applications. Therefore, constructing a high-performance novel nanoenzyme is of great significance for addressing the key technical bottlenecks in the immediate early warning of food safety.

RESULTS: In this study, the developed multi-enzyme activity nanozyme exhibits an enhanced interfacial effect, not only increasing the number of modifiable active sites but also enhancing the contact areas with enzyme substrates. The synergistic anchoring of dual metals effectively reduces the energy barrier of catalytic reactions, thereby further improving the catalytic efficiency of peroxidase-like (POD) and oxidase-like (OXD) activities. This platform can complete the ultra-precise detection of Salmonella Typhimurium within 1 h, with detection limits of 1.78 CFU/mL (POD) and 2.07 CFU/mL (OXD). After confirming the positive test results, the 1O2, •OH, and O2•- generated by multi-enzyme activity nanozyme can achieve highly efficient synergistic bactericidal effects, reaching a 100 % inactivation rate within 30 min. Experimental results demonstrate that the sensing platform exhibits outstanding stability and specificity when detecting untreated wastewater, milk, and beef, fully showcasing its robust practical application potential.

SIGNIFICANCE: This study developed a multifunctional nanoplatform based on interface-enhanced bimetallic nanozymes with multi-enzyme activity for the precise detection and timely elimination of Salmonella Typhimurium in food. This research provides an effective integrated solution for ultra-sensitive detection and immediate, efficient sterilization in food safety monitoring, and has significant practical application value and promising prospects.