Differential pulsed voltammetry of Δ9‐Tetrahydrocannabinol (THC) on disposable screen‐printed carbon electrodes: A potential in‐field method to detect Δ9‐THC in saliva

Abstract

AbstractDue to recent legalization of marijuana across many states in the U.S., there is an increased concern of users driving while impaired/intoxicated with Δ9‐tetrahydrocannabinol (Δ9‐THC), the principal psychoactive constituent of cannabis/marijuana. Hence, there is a need for a rapid roadside detection of this drug that can be used to accurately screen drivers. Current field sobriety tests rely on a series of physical and mental exercises administered during DUI investigations to help determine a driver's level of impairment. Due to their portability and effectiveness, screen printed carbon electrodes (SPCEs) are ideal to work with when it comes to devising a low‐cost screening device for roadside testing. SPCE's can potentially detect low levels of Δ9‐THC in an individual's saliva via electrochemical oxidation of Δ9‐THC. Herein we report a fast, cheap, and accurate approach to electrochemically detect 1–20 μM Δ9‐THC in a 1 mL sample of artificial oral fluid (AF‐OF) diluted to 50 % with a buffer/electrolyte solution using differential pulse voltammetry (DPV) at the surface of a small SPCE. Implications for the use of this method to screen intoxicated drivers are discussed.