Preparation of a multifunctional and ultrasensitive Au@AgNPs-Van/PDMS film SERS substrate for rapid detection of foodborne pathogens in beef

We present a novel and super-sensitive vancomycin (Van) modified Au@AgNP self-assembly with polydimethylsiloxane (PDMS) (Au@AgNPs/Van-PDMS) film surface-enhanced Raman scattering (SERS) substrate for identification of foodborne pathogens in beef, without the need for in vitro bacterial culture. The results illustrated that the Au@AgNPs/Van-PDMS film exhibited high reproducibility and Raman enhancement effect (1.09 x 105). Clostridium perfringens, Bacillus subtilis and Staphylococcus aureus isolated from beef captured by Au@AgNPs/Van-PDMS film exhibited high reproducibility and significant differences. Principal component analysis score plots distinguished classes of foodborne pathogens, and the qualitative identification of linear discriminant analysis was correct at 100%. The detection limit of S. aureus in beef was as low as 3 CFU/mL. This method could provide an effective means and technical support for realizing the application of SERS technology for quick and highly sensitive detection of foodborne pathogens in complex environments.

Automated summary

This study presents a novel Au@AgNP self-assembly with PDMS film surface-enhanced Raman scattering (SERS) substrate for quick and highly sensitive detection of foodborne pathogens in beef. The method does not require bacterial culture and exhibits high reproducibility and Raman enhancement effect. It can effectively distinguish different classes of pathogens.