Rapid detection of foodborne pathogens by flexible SERS substrate based on filter paper

• 1、School of Food Science and Technology, Jiangnan University, Wuxi 214122, China

Abstract：I Fast, reliable and cost-effective bacterial differentiation is an important issue in many areas such as human health care, food safety, forensics and environmental science. In this experiment, Au@Ag nanoparticles (Au@Ag NPs) were synthesized by seed growth method, and were self-assembled on a filter paper sheet by dip coating to prepare a flexible SERS substrate based on filter paper. Raman beacon molecule 4-mercapto Benzoic acid (4-MBA) was used to evaluate the SERS performance of the substrate. Five foodborne pathogens (Salmonella typhimurium, Staphylococcus aureus, Escherichia coli, Shigella flexneri, Listeria monocytogenes) were added to the substrate respectively for SERS signal measurement. The positions of the main peaks of the SERS spectra of the five bacteria are similar, but the relative intensities of the vibration peaks are significantly different, and different strains have unique Raman peaks. The principal component analysis (PCA) method was combined with bacterial SERS spectra for rapid identification of foodborne pathogens. The results showed that the data points of the five bacteria were clustered into five independent clusters. At the same time, quantitative detection of Staphylococcus aureus and Salmonella typhimurium, the minimum detection limit was 105 cfu / mL.

Keywords： Pathogenic bacteria Au@Ag nanoparticles Filter paper PCA Food safety