W Booth School of Engineering Practice and Technology, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4L8, Canada.
Analyst. 2021 Jan 21;146(2):574-580. doi: 10.1039/d0an01850c. Epub 2020 Nov 11.
Cannabis, also known as marijuana, is the most abused psychoactive drug worldwide. Several countries are legalizing the medicinal and recreational use of cannabis. At the same time, stricter laws are being drafted for driving or working under the influence of the drug. Therefore, there is a significant need for rapid point-of-care testing of cannabis in biological fluids. Tetrahydrocannabinol (THC) is the parent psychoactive molecule present in cannabis and is used as a biomarker for cannabis detection. In this work, we developed an upconverting nanoparticle (UCNP) based lateral-flow immunoassay (LFIA) for the point-of-care quantitative detection of THC in oral fluids of drug-impaired personnel. UCNPs convert near-infrared excitation into visible emissions and have superior properties over other fluorescent nanoparticles. We employed a novel signal amplification technique for enhancing the sensitivity of LFIA. Contrary to standard LFIA biosensors, we integrated an additional enhancement pad (EP) between the conjugate pad (CP) and nitrocellulose membrane. UCNPs dually conjugated with THC specific immunoglobulin G and streptavidin (UCNP-IgG-SA) and UCNPs conjugated with biotin (UCNP-biotin) were dried in CP and EP, respectively. UCNP-IgG-SA, upon interacting with THC, flow through the EP and bind with UCNP-biotin, consequently forming bright UCNP clusters on the test and control zones. The test signals were captured after an assay time of 20 minutes. An experimental detection limit of 2 ng mL for THC with a linear detection range of 2-15 ng mL was achieved. The developed LFIA has the potential to be used as a point-of-care detection device for the quantitative detection of THC.
大麻，又称 marijuana，是全球范围内最滥用的精神活性药物。一些国家正在使大麻的医疗和娱乐用途合法化。与此同时，针对受药物影响下开车或工作的行为，也在制定更严格的法律。因此，在生物液中对大麻进行即时检测的需求显著增加。四氢大麻酚（THC）是存在于大麻中的母体精神活性分子，被用作大麻检测的生物标志物。在这项工作中，我们开发了一种基于上转换纳米粒子（UCNP）的侧向流动免疫分析（LFIA），用于即时检测药物滥用人员口腔液中的 THC。UCNP 将近红外激发转换为可见发射，优于其他荧光纳米粒子。我们采用了一种新颖的信号放大技术来提高 LFIA 的灵敏度。与标准 LFIA 生物传感器不同，我们在结合垫（CP）和硝酸纤维素膜之间集成了一个额外的增强垫（EP）。UCNP 分别与 THC 特异性免疫球蛋白 G 和链霉亲和素（UCNP-IgG-SA）以及生物素（UCNP-biotin）双重缀合，然后分别干燥在 CP 和 EP 中。UCNP-IgG-SA 与 THC 相互作用后，流经 EP 并与 UCNP-biotin 结合，从而在测试和对照区形成明亮的 UCNP 簇。在 20 分钟的测定时间后，捕获测试信号。实现了 THC 的实验检测限为 2ng mL，线性检测范围为 2-15ng mL。所开发的 LFIA 有可能成为用于 THC 定量检测的即时检测设备。
