SERS-based immunoassay for amplified detection of food hazards: Recent advances and future trends

It is an enormous figure that food fraud causes losses to the global food industry every year. Timely and accurate food authentication technology is a vital means to prevent food fraud. Novel immunoassays, especially surface-enhanced Raman scattering (SERS)-based immunoassays, with terrific specificity and unique charm of ultra-high sensitivity and spectral resolution, have attracted widespread interest in the detection of food hazards. Ultra-sensitivity, fingerprint recognition, and excellent multi-detection capability are the advantages of SERS-based immunoassays, which will help advance food safety regulation. Tracking the timeline of the independent evolution and combination of immunoassay and SERS, we provide a systemic view to describe the trends of surface-enhanced Raman scattering (SERS)-based immunoassays. Moreover, an overview of the enhancement mechanisms of SERS and the classification of its substrate structures, both single and composite, is presented. In particular, the different types of SERS immunoassays are classified, including competitive and non-competitive, labeled and label-free. Different SERS immune sensing strategies and the advantages of their applications, which are essential for further innovation, are discussed. Finally, the summary of representative SERS-based immunoassay applications for food hazard detection is followed by an outlook for research in this extremely promising frontier field. SERS-based immunoassay has become a forceful analytical means for monitoring harmful substances in food, offering new hope for food safety regulation. However, much work remains to be done to commercialize the concept study successfully.