SERS-tag technology in food safety and detection: sensing from the “fingerprint” region to the “biological-silent” region

Surface enhanced Raman spectroscopy (SERS) offers many advantages for the fast and sensitive detection of specific compounds, metal ions or pathogens in foods, motivating to its increasing utilization in food safety. SERS-tags, typically constructed using signal enhanced substrate, Raman reporter molecules, a biocompatible protective layer and a specific recognition element, provide a powerful tool for the analysis of food hazards. This article reviews recent progress in the development of SERS-tags for food safety assessment covering SERS-tags with characteristic peaks in the “fingerprint” region (800–1 800 cm^–1) and the “biological-silent” region (1 800–2 800 cm^–1). Following a brief description of SERS substrates, the design, synthesis and applications of SERS-tag are explored in detail. The application of SERS-tags technology for the detection of microorganisms, pesticides and antibiotics are then investigated. Finally, the prospects of using SERS-tag in real-world food safety analysis are critically discussed.