SERS-LFIA for foodborne pathogenic bacteria and biotoxins: Current limitations and future perspectives

Foodborne pathogenic bacteria and biotoxins remain major threats to food safety, creating a strong demand for rapid, sensitive and field-deployable detection methods. Surface-enhanced Raman scattering lateral flow immunoassay (SERS-LFIA) combines the operational simplicity of LFIA with the quantitative sensitivity and multiplexing capability of SERS, but its practical performance is influenced by nanotag design, recognition elements, food matrices, sample pretreatment and Raman acquisition. This review critically examines SERS-LFIA for the detection of foodborne bacteria, protein toxins and mycotoxins from a materials-to-measurement perspective, linking SERS enhancement and nanotag design with target recognition, matrix compatibility, Raman acquisition and analytical reliability. Representative studies are discussed from the perspectives of analytical sensitivity, matrix compatibility, reproducibility, storage stability, multiplexing capability and agreement with reference methods, with particular emphasis on analytical reliability under real-food conditions. Key challenges associated with matrix interference, quantitative validation, signal reproducibility and practical implementation are further highlighted. Finally, portable Raman readers, automated spectral interpretation, risk-oriented multiplex panels, integrated workflows and the coordinated use of confirmatory methods are highlighted as important directions for the future translation of SERS-LFIA toward practical food-safety screening.