Fentanyl is a synthetic opioid prescribed for pain management, but has been increasingly used as an adulterant in illicit substances. Fentanyl is harmful enough that 2 milligrams can cause an overdose, and has been recently implicated in the sharp increase of drug-related deaths in the United States. Current field detection methods utilize color tests. These methods have inherent bias and can result in false positives. They also require on-site reagent mixing, and microscopic quantities of material, making them unsuitable for safe field testing. The use of instrumental methods in the field can provide positive identification of the unknown substance, without direct handling. Three methods were evaluated for their ease of use, cost, and sensitivity in a field setting. The use of a paper-based Surface-enhanced Raman Spectroscopy (SERS) substrate with a suspension of silver nanoparticles (AgNPs), allowed for the detection of nanogram quantities of Fentanyl.1 Additionally, Ion Mobility Spectroscopy (IMS) allowed for the rapid sampling of nanogram quantities of material from the outside of a plastic bag, and detection was unaffected by the complex matrices.2 Finally, the development of an electrochemical cell will be discussed which combined the coupling of Cyclic Square Wave Voltammetry (CSWV) and low-cost RTIL-modified electrochemical strips lead to a distinct redox signature of fentanyl and to rapid identification of the drug.3
1) Haddad, A.; et al. Detection And Quantitation Of Trace Fentanyl In Heroin By Surface-Enhanced Raman Spectroscopy. Analytical Chemistry 2018, 90 (21), 12678-12685.
2) Sisco, E.; et al. Rapid Detection Of Fentanyl, Fentanyl Analogues, And Opioids For On-Site Or Laboratory Based Drug Seizure Screening Using Thermal Desorption DART-MS And Ion Mobility Spectrometry. Forensic Chemistry 2017, 4, 108-115.
3) Goodchild, S.; et al. Ionic Liquid-Modified Disposable Electrochemical Sensor Strip For Analysis Of Fentanyl. Analytical Chemistry 2019, 91 (5), 3747-3753.