Progress of the applications of surface-enhanced Raman spectroscopy in illicit drug detection

Surface-enhanced Raman spectroscopy (SERS) is a Raman spectroscopy technology that can enhance the analyte signal with the help of noble nanomaterials. Due to the merits of fingerprint recognition, high sensitivity, high accuracy, fast and non-destructive detection, and no interference from water. More and more attentions are being paid to SERS, especially in the application of trace drug-detection on site in forensic science. SERS is not only used for the detection of pure solutions, but also gradually expanded to complex, including seized drugs and human specimen. This review focused on the types and methods of SERS for the detection of drugs, introduced the development of enhanced substrates for drug detection, and the progress of SERS-based detection technology, and summarized the analysis methods of SERS data. Finally, we discussed the main challenges of SERS used on-site drug-detection and proposed the development trend of trace-detection based on SERS.