Majak Darren, Fan Jiaxin, Kang Seongdae, Gupta Manisha
Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
J Mater Chem B. 2021 Mar 4;9(8):2107-2117. doi: 10.1039/d0tb02951c.
Recreational use of marijuana/cannabis was legalized in Canada in 2018 and has been decriminalized in several other countries; however, the detection of impairment has remained elusive for law enforcement. The psychoactive ingredient in cannabis, delta-9-tetrahydrocannabinol (Δ9-THC), can be detected in saliva and be correlated well with the intake of cannabis. Organic electrochemical transistors (OECTs) have been used for a variety of biosensing applications like glucose, pH, ions, etc. In this work, we demonstrate the use of unfunctionalized OECTs for the detection of Δ9-THC down to 0.1 nM and 1 nM diluted in DI water and synthetic saliva buffer, respectively. These OECTs have been aerosol jet printed entirely with PEDOT:PSS as the channel material. Using a platinum gate coupled with an aerosol jet printed OECT, Δ9-THC concentration can be detected due to its oxidation reaction at the gate. These results were consistent with cyclic voltammetry measurements of Δ9-THC using Pt as the working and counter electrode. Utilizing these OECT based sensors, we have achieved high sensitivity of detection of Δ9-THC in the range from 0.1 nM to 5 μM. These OECT based Δ9-THC sensors demonstrate less than 3% error indicating good repeatability which is averaged over 15 measurements on multiple devices.
2018年，加拿大将娱乐性使用大麻合法化，其他一些国家也已将其非刑罪化；然而，执法部门仍难以检测到大麻导致的身体机能受损情况。大麻中的精神活性成分Δ9-四氢大麻酚（Δ9-THC）可在唾液中检测到，且与大麻摄入量有良好的相关性。有机电化学晶体管（OECT）已用于多种生物传感应用，如葡萄糖、pH值、离子等的检测。在这项工作中，我们展示了使用未功能化的OECT分别检测去离子水中稀释至0.
