Dual-mode aptasensors based on AuNPs and Ag@Au NPs for simultaneous detection of foodborne pathogens

Food safety detection is developing rapidly and with high throughput. Nanoparticles have obvious advantages in foodborne pathogens detection, among which gold nanoparticles (AuNPs) are widely used due to their stable chemical and optical properties. In this study, two kinds of aptasensors based on AuNPs were established. The first one was a visual detection method based on AuNPs lateral flow aptasensor, and the other one was a surface-enhanced Raman spectroscopy (SERS) aptasensor detection based on silver-core gold-shell nanoparticles ([email protected]). The former allowed for visual readings, eliminated the need for machines, which achieved an initial diagnosis of three common pathogenic bacteria with a detection limit of 20–30 CFU/mL. The sensitivity of the latter can be improved by [email protected] and the detection limit reached 2 CFU/mL, which can achieve high sensitivity and high-throughput detection. We systematically studied the structure, function and optical signal characteristics of AuNPs in detection, which can provide a favorable reference for the detection of foodborne pathogens in the future.