The combination of microfluidic technology and surface-enhanced Raman spectroscopy (SERS) has the advantages of being label-free, fingerprint spectroscopy, and high sensitivity, which giving the combination great potential for rapid trace-level biological and environmental analysis. In this review, we summarized the recent progress in these two fields, e.g., microfluidics and SERS, including the basic strategies of a simple and versatile microfluidic-SERS detection system and its wide-ranging applications. Moreover, we listed the main challenges and future directions of the microfluidic-SERS systems; proposed on-chip applications beyond SERS; developed a more efficient, more sensitive, and more convenient microfluidic-SERS system; and formed a more complete on-site real-time detection technology.

It has long been desired to develop rapid methods for the rapid identification and quantification of pesticides and their metabolites. Carbofuran, a representative pesticide of the carbamate group, is highly systemic and is used on vegetables, fruits and grains, which has led many countries to test for residues in food and the environment. In this study, gold and silver composite core–shell (Au@Ag) nanoparticles were used to label the carbofuran antibody and Raman molecule 5,5-dithiobis-2-nitrobenzoic acid (DTNB) to synthesize Raman immune probes. The signal value of DTNB was read using a Raman spectrometer, and the quantitative detection technology of carbofuran was established based on lateral flow immunochromatographic assay (ICA) combined with surface-enhanced Raman spectroscopy (SERS). SERS-ICA is a rapid, quantitative and ultrasensitive test for the determination of carbofuran in fruits and vegetables with a sensitivity of 0.1 pg mL⁻¹. Consequently, the results demonstrate that the SERS-based lateral flow immunosensor developed in this study has the advantages of excellent assay sensitivity and remarkable multiplexing capability, and thus it will have great application potential in food safety monitoring.