Label-free SERS detection of foodborne pathogens based on a flexible PMMA-BP@MoS2 binary substrate

Abstract

Foodborne pathogenic bacteria, acting as direct or indirect contaminants of food and water sources, have emerged as a significant global food safety issue. Thus, the advancement of rapid, sensitive, and precise methods for detecting foodborne pathogens is of paramount importance for effective food safety monitoring. In response to this critical need, we have successfully prepared a flexible PMMA-BP@MoS₂-based surface-enhanced Raman scattering (SERS) substrate through a two-step strategy involving hydrothermal synthesis and spin coating. This novel substrate enables label-free and highly sensitive detection of foodborne pathogens. The synergistic chemical enhancement effect of BP@MoS₂ on target molecules, coupled with the highly efficient molecular enrichment capability endowed by PMMA integration, endows the proposed binary substrate with remarkable SERS enhancement properties and stability. These characteristics significantly reduce the detection limit of model molecules to as low as 6.67 × 10⁻⁷ M. Furthermore, trace levels of Escherichia coli in raw meat samples were effectively detected using the PMMA-BP@MoS₂ flexible substrate, achieving a wide linear detection range from 6.46 × 10⁴ to 6.46 × 10⁸ CFU mL⁻¹. The flexible PMMA-BP@MoS₂ SERS substrate emerged as a promising solution for nondestructive and highly sensitive bacterial detection, paving the way for clinical diagnostics of diseases caused by foodborne pathogens and offering a valuable tool to address food safety challenges.