Functionalization of metal Nanoparticles for SERS-based Detections of illicit drugs in biological samples

Abstract

Surface-enhanced Raman scattering (SERS) has been widely used for the detection of illicit drugs due to its excellent chemical fingerprint information, high sensitivity by plasmon-enhanced excitation and scattering, and independence of aqueous solution impact. Even though it has been more than one decade since the first SERS was synthesized, extensive effort has recently been undertaken to improve hand-held Raman analyzer and make SERS a practical point-of-care (POC) device for the detection of illicit drugs in real samples. Lately, there has been a fast growth in improving methods for precise control over metal nanoparticle size and modification of their detection performance with functionalizing agents, which will dramatically enhance their application in various biomedical applications.In this study, a general view on the background of the SERS and several basic concepts and focuses are discussed. Then we put forward a summary of the progress in trace determination of illicit drugs using various functionalization methods for enhancing characteristics of the substrate toward a more selective detection of the analytes.