This study involved the quantitative determination of fentanyl in heroin and cocaine using SERS, using a point-and-shoot handheld Raman system.
Recently there has been upsurge in reports that illicit seizures of cocaine and heroin have been adulterated with fentanyl. Surface-enhanced Raman spectroscopy (SERS) provides a useful alternative to current screening procedures that permits detection of trace levels of fentanyl in mixtures. Samples are solubilized and allowed to interact with aggregated colloidal nanostars to produce a rapid and sensitive assay. The protocol of the current study was optimized to detect pure fentanyl down to 0.20 ± 0.06 ng/mL and also distinguish pure cocaine and heroin at ng/mL levels. Multiplex analysis of mixtures was enabled by combining SERS detection with principal component analysis and super partial least squares regression discriminate analysis (SPLS-DA), which enables the determination of fentanyl as low as 0.05 percent in simulated seized heroin and 0.10 percent in simulated seized cocaine samples. (publisher abstract modified)