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

Area of Science:

• Materials Science
• Analytical Chemistry
• Food Safety

Background:

• Foodborne pathogenic bacteria pose a significant global food safety risk, necessitating rapid and sensitive detection methods.
• Current detection methods often lack the speed, sensitivity, or precision required for effective food safety monitoring.
• Developing advanced analytical tools is crucial for safeguarding public health against foodborne illnesses.

Purpose of the Study:

• To develop a novel, flexible surface-enhanced Raman scattering (SERS) substrate for highly sensitive and label-free detection of foodborne pathogens.
• To investigate the synergistic enhancement effects of black phosphorus (BP) and molybdenum disulfide (MoS2) integrated with polymethyl methacrylate (PMMA) for SERS applications.
• To demonstrate the practical utility of the PMMA-BP@MoS2 substrate for detecting specific foodborne bacteria in real-world samples.

Main Methods:

• Fabrication of a flexible PMMA-BP@MoS2 SERS substrate using a two-step hydrothermal synthesis and spin-coating strategy.
• Characterization of the substrate's morphology, composition, and SERS performance.
• Quantitative detection of model molecules and trace levels of Escherichia coli in raw meat samples using the developed SERS substrate.

Main Results:

• The PMMA-BP@MoS2 substrate exhibited remarkable SERS enhancement properties and stability due to synergistic effects.
• A significantly reduced detection limit for model molecules was achieved, reaching as low as 6.67 × 10^-7 M.
• Effective detection of trace Escherichia coli in raw meat samples was demonstrated over a wide linear range (6.46 × 10^4 to 6.46 × 10^8 CFU mL^-1).

Conclusions:

• The flexible PMMA-BP@MoS2 SERS substrate provides a promising platform for nondestructive, highly sensitive bacterial detection.
• This technology offers a valuable tool for addressing critical food safety challenges and monitoring foodborne pathogens.
• The developed substrate has potential applications in clinical diagnostics for diseases caused by foodborne pathogens.