Rapid identification and quantification of opioid drugs is of great importance in the face of an ongoing opioid epidemic in the United States. Yet techniques for trace analysis of these opioids, particularly for fentanyl, an extremely potent synthetic drug of abuse and the main driver of the current wave of opioid crisis, are often not readily accessible. Therefore, a fast, sensitive and quantitative technique, with excellent portability, for opioids analysis is highly desirable. Such a technique can potentially offer crucial information for not only drug control officials but also health professionals and/or communities on the frontlines of this crisis.
We therefore propose a portable Raman approach by pairing an easy to perform procedure with a compact Raman spectrometer suitable for rapid, on-site identification and quantification for trace fentanyl analysis. Fentanyl spiked in urine was detected at concentrations as low as several nanogram per mL. Portable SERS also allows detection of trace fentanyl laced in recreational drugs at mass concentrations as low as 0.05% in other common opioid drugs. Furthermore, multiplexing fentanyl in mixtures was easily achieved with multivariate data analysis. In sum, we developed a rapid, highly sensitive and reliably quantitative technique for trace fentanyl analysis based on portable Raman coupled with surface enhanced Raman scattering.