Background Pathogenic bacteria have always been a significant threat to human health. The detection of pathogens needs to be rapid, accurate, and convenient. Methods We present a sensitive surface-enhanced Raman scattering (SERS) biosensor based on the combination of vancomycin-modified Ag-coated magnetic nanoparticles (Fe 3 O 4 @Ag-Van MNPs) and Au@Ag nanoparticles (NPs) that can effectively capture and discriminate bacterial pathogens from solution. The high-performance Fe 3 O 4 @Ag MNPs were modified with vancomycin and used as bacteria capturer for magnetic separation and enrichment. The modified MNPS were found to exhibit strong affinity with a broad range of Gram-positive and Gram-negative bacteria. After separating and rinsing bacteria, Fe 3 O 4 @Ag-Van MNPs and Au@Ag NPs were synergistically used to construct a very large number of hot spots on bacteria cells, leading to ultrasensitive SERS detection. Results The dominant merits of our dual enhanced strategy included high bacterial-capture efficiency (>65%) within a wide pH range (pH 3.0–11.0), a short assay time (<30 min), and a low detection limit (5×10 2 cells/mL). Moreover, the spiked tests show that this method is still valid in milk and blood samples. Owing to these capabilities, the combined system enabled the sensitive and specific discrimination of different pathogens in complex solution, as verified by its detection of Gram-positive bacterium Escherichia coli , Gram-positive bacterium Staphylococcus aureus , and methicillin-resistant S. aureus . Conclusion This method has great potential for field applications in food safety, environmental monitoring, and infectious disease diagnosis.

The serious threat of antibiotic-resistant bacterial infections has brought an urgent need for the development of new antibacterial nanomaterials. We encapsulate glutathione (GSH)-protected gold nanoclusters (AuNCs) in zeolitic imidazolate frameworks-8 (ZIF-8) and present their potential in antibacterial capabilities. Under white light irradiation, AuNCs-embedded ZIF-8 nanocomposites show assembly-enhanced emission and reactive oxygen species (ROS) generation. AuNCs@ZIF-8 exhibit almost complete inactivation of bacterial growth within 60 min of light irradiation. Scanning electron microscopic results show that AuNCs@ZIF-8 nanocomposites are captured by bacterial cells, and the leakage of alkaline phosphatase and nucleotides from bacteria demonstrate that the photoinduced ROS can easily destroy the bacterial surface and totally kill the bacteria. Herein, our antibacterial nanocomposites have photoenhanced bactericidal capability and show promising applications for sterilization.

Bacterial infection has increasingly affected people’s life, therefore it is significant to explore novel antibacterial agents and strategies for efficient disinfection. Herein, we designed ZIF-8 based composites ICG@ZIF-8/PDA/Ag, which encapsulate...

A hollow core-satellite ZIF-8/PDA/AgNPs was established and studied as an antibacterial agent. Polydopamine (PDA) was coated on ZIF-8 surface to form a hollow structure because ZIF-8 core was etched by the chelation of PDA and Zn2+. Then AgNPs were homogeneously decorated on the surface of ZIF-8/PDA by in situ reduction of Ag+ to avoid their aggregation. ZIF-8/PDA/AgNPs have good antibacterial activity, and they can totally inhibit bacterial growth at the concentration of 16 µg mL−1.