Surface-enhanced Raman spectroscopy as a tool for food and environmental monitoring of pesticides: recent trends and perspectives.

Surface-enhanced Raman spectroscopy (SERS) has emerged as a powerful analytical tool for ultrasensitive detection of environmental contaminants, particularly pesticides. Recent developments have focused on nanomaterials engineering and SERS-active sensors to enhance signal intensity. Gold (AuNPs) and silver nanoparticles (AgNPs) of various morphologies and sizes have been widely explored due to their plasmonic properties, as well as hybrid or combined nanoparticle systems. Innovative approaches have also been developed, such as embedding nanoparticles in gels to enhance stability and reproducibility or using magnetic nanoparticles for sample interaction and preconcentration. Additionally, the integration of graphene oxide has gained attention because of its ability to improve the chemical enhancement mechanism via π-π interactions with analyte molecules. Despite these advances, SERS-based detection remains challenging, particularly with regard to selectivity in complex matrices. To address this issue, recent strategies have combined SERS substrates with biorecognition molecules such as antibodies, aptamers, and enzymes, thereby improving specificity and facilitating the development of SERS-based biosensors. This review highlights the current state-of-the-art SERS applications for pesticide detection in food and environmental samples, discussing the key technological advances, material innovations, and analytical challenges. This paper also offers perspectives on future research directions to increase the sensitivity, reproducibility, and field applicability of SERS-based detection platforms.