Magnetic surface-enhanced Raman scattering (MagSERS) biosensors for microbial food safety: Fundamentals and applications

Background: Microbiological safety of food is closely related to the activities of foodborne microorganisms, which is among the critical issues in the food industry that require careful screening. A series of analytical techniques have been employed for microbiological food safety detection but renders either analytical defects or practical limitations. With the sensitive and fingerprint sensing ability of surface-enhanced Raman scattering (SERS) technique and the easy operations of magnetic entities (MEs), SERS-based magnetic platforms (MagSERS) emerge as a potent candidate for the analysis of microbiological foodborne hazards. Scope and approach: The current review focuses on the fundamentals and recent applications of MagSERS in microbiological safety of food. In this review, the design and fabrication of MagSERS are introduced, which comprises the functionalized MEs plus noble-metal SERS substrates, magnetic nanocomposites plus noble-metal SERS substrates, and magnetic SERS substrates, and the detection principles of MagSERS are illustrated in detail, including the combination of magnetic capture, separation, and enrichment of targets (via recognition elements functionalized MEs) with SERS substrates, as well as the magnetism-mediated hotspot engineering of SERS substrates. In addition, the current advances in MagSERS methods for detecting foodborne bacteria, biological toxins, and viruses are summarized and future perspectives for the food industry are also given. Key findings and conclusions: As demonstrated by the publications in the field, MagSERS that merges magnetic properties and SERS spectra can facilitate the detection of foodborne biohazards for their excellent target separation and enrichment (sampling), simplified assay procedures (assaying), optimized SERS effect and signal or signalling. As such, MagSERS platforms show a promising prospect in the construction of more simple, rapid, and sensitive biosensors for food safety.

Automated summary

MagSERS platforms, combining magnetic properties and SERS spectra, have shown promising prospects in simplifying, speeding up, and enhancing the sensitivity of biosensors for foodborne biohazards detection. The integration of magnetic capture, separation, and enrichment with SERS substrates, as well as magnetism-mediated hotspot engineering of SERS substrates, is key to the success of MagSERS in food safety analysis.