Multifunctional Cu2O@Ag probe for ultra-sensitive SERS detection and inhibition of Escherichia coli O157: H7.

Abstract

Escherichia coli (E. coli) O157:H7 is a prevalent foodborne pathogen threatening public health, but its practical detection suffers from poor selectivity, long time consumption, and matrix interference. This study aimed to develop an integrated platform for rapid, sensitive detection and inhibition of E. coli O157:H7. A sandwich surface-enhanced Raman spectroscopy (SERS) sensor was constructed using antibody-functionalized silver-coated Cu2O nanoparticles (Cu2O@Ag NPs). The optimized sensor achieved sensitive detection of E. coli O157:H7 in contaminated milk within 22 min with an ultra-low limit of detection (LOD) of 1 CFU/mL. Additionally, Cu2O@Ag NPs exhibited excellent antibacterial activity, with minimum inhibitory concentrations (MIC) of 62.5 μg/mL (E. coli O157:H7) and 125 μg/mL (Staphylococcus aureus). This work integrates high-sensitivity bacterial detection with intrinsic antibacterial functionality into a single platform, offering a promising solution for on-site monitoring and control of foodborne pathogens, thereby advancing food safety assurance and public health protection.