Advances in Multifunctional Nanoagents and SERS-Based Multimodal Sensing for Biotoxin in Foods

Biotoxins, toxic substances produced by living organisms, are widely present in food and pose a major threat to human health. Traditional detection methods, such as gas chromatography-mass spectrometry (GC-MS) and enzyme-linked immunosorbent assay (ELISA), often suffer from limitations including complex sample preparation, high costs, and lengthy analysis times. In response, surface-enhanced Raman spectroscopy (SERS) has emerged as a highly sensitive and specific analytical tool for the detection of biotoxins. This review highlights the recent progress in multimodal detection technologies based on SERS, focusing on the design and classification of multimodal materials to optimize the construction of SERS substrates. The integration of SERS with other detection modalities, such as fluorescence, colorimetry, and electrochemistry, is discussed to enhance the accuracy and diversity of biotoxin detection. Finally, the review critically assesses the current challenges and future prospects of SERS multimodal detection technology, particularly in real-time food safety monitoring and on-site diagnostics, offering critical insights to guide future research directions.