The abuse of opioids has been a critical issue to the public health for years. With the appearance of new fentanyl analogs, the overdose rates of opioids continue to bloom. Current screening methods, such as immunoassay, have difficulty detecting the full range of opioid analogues due to a wide variety of structural variations. We have been working on alternative screening methods, Electrochemical approaches, including square wave voltammetry and cyclic voltammetry, quickly distinguish the group of fentanyl analogs from other opioids with lower cost and easier operations. Both screening approaches are convenient for point-of-care analysis and laboratory tests.

The electrochemical approaches utilize the SPE electrodes and PBS buffer. When the solid drugs were dissolved in the buffer solutions, then dropped on electrodes and analyzed via CHI instrument with an energy range of 0.5 – 1.8 eV. The SWV spectra identify fentanyl analogs from mixtures with the optimized condition for individual drugs, such as fentanyl, cocaine, heroin, opioids, amphetamines, and adulterants. Electrochemical approaches are less sensitive than instrumental methods, however, its operations and preparations are easier for un-trained staff. To understand the cross reaction of fentanyl analogs and impurities, as well as the metabolites, DFT calculations displayed the energy changes and pathways from parent drugs to metabolites.

The electrochemical method permits a rapid, easily operated presumptive test for opioids in different benefits. When the method coupled with other screening methods, such as surface enhanced Raman spectroscopy our lab have done, the method can be orthogonal to mass spectrometry and sufficiently sensitive to detect compounds at toxicological levels. As a result it should be particularly useful for the screening of opioids and other novel psychoactive substances.