Center for Systems Biology, Massachusetts General Hospital Research Institute, Boston, MA 02114, USA.
Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
Sci Transl Med. 2021 Oct 20;13(616):eabe2352. doi: 10.1126/scitranslmed.abe2352.
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 ( = 43) and controls ( = 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).
四氢大麻酚（THC）是大麻中的主要精神活性成分，会以浓度依赖的方式损害认知和运动功能。药物检测通常用于就业和执法目的；然而，现有的检测方法产生低敏感的二元结果（侧向流动分析）或检测时间长（气相色谱-质谱法）。为了能够在几分钟内进行现场 THC 定量分析，我们开发了一种称为 EPOCH（现场大麻吸入的快速探针）的口服 THC 分析快速检测方法。EPOCH 的传感器设计独特，具有径向膜和传输光学元件，全部包含在一个紧凑的墨盒中。这种集成方法允许在 5 分钟内完成检测，检测限为 0.17ng/ml THC，低于监管指南（1ng/ml）。作为现场测试的概念验证，我们应用 EPOCH 评估了大麻使用者（=43）和对照组（=43）的口腔液样本。EPOCH 在所有来自大麻吸烟者的样本中都检测到了口服 THC（中位浓度为 478ng/ml），以及摄入了 THC 食物的消费者。纵向监测显示，大麻吸烟后前 6 小时内 THC 浓度迅速下降（半衰期为 1.4 小时）。
