Characterization of Illicit Drugs by Surface-Enhanced Raman Spectroscopy (SERS) and Principal Component Analysis (PCA)

Addictive, illicit drugs pose a high threat of relapse. The deaths related to illicit drugs have substantially increased in the last decade. Globally, the illicit drug trade poses a significant challenge to public health and law enforcement. It is essential to utilize advanced analytical methodologies that can characterize illegal substances precisely to monitor these drugs. Surfaced-enhanced Raman spectroscopy (SERS) has become a valuable tool, providing distinct capabilities for analyzing illegal substances. Surface enhancement enables far more sensitive detection and identification of illicit drugs by suppressing the fluorescence and enhancing the Raman signals. In this regard, a simple method with limited sample processing has been established to characterize illicit drugs that include methamphetamine (MAMP) (ice), bhang, marijuana (cannabis), opium, and diacetylmorphine (heroin). Moreover, principal component analysis (PCA) was employed for the identification of the characteristic SERS spectral features of these drugs. This article examines the potential application of SERS in the characterization of illicit substances, focusing on its ability to contribute significantly to law enforcement and forensic investigation.