Tetrahydrocannabinol (THC), the primary psychoactive ingredient of cannabis, impairs cognitive and motor function in a concentration-dependent fashion. Drug testing is commonly performed for employment and law enforcement purposes; however, available tests produce low-sensitive binary results (lateral flow assays) or have long turnaround (gas chromatography-mass spectrometry). To enable on-site THC quantification in minutes, we developed a rapid assay for oral THC analysis called EPOCH (express probe for on-site cannabis inhalation). EPOCH features distinctive sensor design such as a radial membrane and transmission optics, all contained in a compact cartridge. This integrated approach permitted assay completion within 5 min with a detection limit of 0.17 ng/ml THC, which is below the regulatory guideline (1 ng/ml). As a proof of concept for field testing, we applied EPOCH to assess oral fluid samples from cannabis users (n = 43) and controls (n = 43). EPOCH detected oral THC in all specimens from cannabis smokers (median concentration, 478 ng/ml) and THC-infused food consumers. Longitudinal monitoring showed a fast drop in THC concentrations within the first 6 hours of cannabis smoking (half-life, 1.4 hours).
|Journal||Science Translational Medicine|
|Publication status||Published - 2021 Oct 20|
Bibliographical noteFunding Information:
We acknowledge the following grant support: NIH R21DA049577, R01CA229777, R01CA239078, R01CA237500, DOD-W81XWH1910199, and DODW81XWH1910194 to Hakho Lee; R01CA204019 to R.W.; U01CA233360 to Hakho Lee and C.M.C.; and R01CA264363 to C.M.C.; Robert Wood Johnson Foundation and American Cancer Society to C.M.C.; MGH Scholar Fund to Hakho Lee; National Research Foundation (South Korea) 2017R1A2B3010816 to M.-G.K.; The Ministry of Trade, Industry and Energy (South Korea) 20012362 to Y.-E.Y.; and the Institute for Basic Science Grant (South Korea) IBS-R026-D1 to J. Cheon. We thank K. Chung (University of Illinois at Urbana-Champaign, IL, USA) and N. Jeong (Massachusetts General Hospital, MA, USA) for helpful discussion, M. Garlin (Massachusetts General Hospital) and S.-Y. Cheon (University of Southern California, CA, USA) for helpful discussion on graphic designs and illustrations, and K. Joyce for critically reading the manuscript.
Copyright © 2021 The Authors.
All Science Journal Classification (ASJC) codes