Aptamer-Based Oral Fluid Testing Device for Roadside Screening of Recent Marijuana Use in Drivers

Driving under the influence of drugs is a major cause of vehicular accidents in the US. Marijuana is the most abused drug across the world, and there has been an ever-increasing social acceptance and push towards legalization of medical and recreational marijuana in the US. The use of marijuana is known to severely impair skills pertinent for safe driving. Identifying drivers under the influence of marijuana is important for law enforcement and ensuring public safety. This would require non-invasive quantification of the psychoactive compound tetrahydrocannabinol (THC) in breath condensate or oral fluid at the roadside. However, devices for these purposes are either far from commercialization or do not have the requisite sensitivity and specificity. Therefore, there is an urgent need to develop a device like the standard alcohol breath analyzer that can be used by law enforcement personnel to accurately quantify THC levels non-invasively in roadside scenarios.

This project focuses on developing an aptamer-modified paper electrochemical device (aPED) that can be used by law enforcement officials as a user-friendly tool to quantify THC in the oral fluid of drivers. The device will require only ~10-20 microliters of sample and provides results in a digital readout within seconds. This project has three aims. In Aim 1, a DNA aptamer will be generated to bind THC with high affinity and specificity. Aptamers are artificial nucleic-acid-based bioreceptors that bind to specific molecules with high affinity, and they have been widely adopted into sensors to detect a variety of drug targets. In Aim 2, the THC-binding aptamer will be utilized to fabricate an electrochemical aptamer-based sensor. In Aim 3, after sensor optimization in Aim 2, aPEDs will be developed and validated using guidelines from the American Association of Forensic Sciences Academy Standards Board. The device is anticipated to have a detection limit of 5 ng/ml, which will enable identification of drivers that have consumed marijuana very recently in time. The aPED will fulfill the need of the forensic community for a reliable means of detecting THC to allow law enforcement to facilitate further investigation of drivers suspected of driving under the influence of drugs. CA/NCF