Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States.
Department of Electrical Engineering, Stanford University , Stanford, California 94305, United States.
Anal Chem. 2016 Aug 2;88(15):7457-61. doi: 10.1021/acs.analchem.6b01688. Epub 2016 Jul 21.
As medical and recreational use of cannabis, or marijuana, becomes more prevalent, law enforcement needs a tool to evaluate whether drivers are operating vehicles under the influence of cannabis, specifically the psychoactive substance, tetrahydrocannabinol (THC). However, the cutoff concentration of THC that causes impairment is still controversial, and current on-site screening tools are not sensitive enough to detect trace amounts of THC in oral fluids. Here we present a novel sensing platform that employs giant magnetoresistive (GMR) biosensors integrated with a portable reader system and smartphone to detect THC in saliva using competitive assays. With a simple saliva collection scheme, we have optimized the assay to measure THC in the range from 0 to 50 ng/mL, covering most cutoff values proposed in previous studies. This work facilitates on-site screening for THC and shows potential for testing of other small molecule drugs and analytes in point-of-care (POC) settings.
随着大麻（或 marijuana，即医用和消遣用大麻）的医用和消遣用用途变得越来越普遍，执法部门需要一种工具来评估驾驶员是否在受到大麻（specifically the psychoactive substance, tetrahydrocannabinol (THC)，即四氢大麻酚，大麻中的精神活性成分）影响的情况下驾驶车辆。然而，导致损伤的 THC 临界浓度仍然存在争议，并且当前的现场筛查工具不够灵敏，无法检测到口腔液中痕量的 THC。在这里，我们提出了一种使用巨磁电阻（Giant Magnetoresistive，GMR）生物传感器与便携式读取器系统和智能手机集成的新型传感平台，用于使用竞争性测定法检测唾液中的 THC。通过简单的唾液收集方案，我们优化了检测方法，使其能够测量 0 到 50ng/mL 范围内的 THC，涵盖了之前研究中提出的大多数临界值。这项工作促进了现场筛查 THC 的工作，并展示了在即时护理（Point-of-Care，POC）环境中测试其他小分子药物和分析物的潜力。
