A team of bioengineers from the Erik Jonsson School of Engineering and Computer Science at the University of Texas (Dallas) have developed a THC biosensor that uses a saliva sample to quickly and accurately test the level of THC in a person.
It is expected that new device will soon be put into use by law enforcement agencies throughout the US for roadside impairment tests, Phys.org reported. The test requires just a swab of the inside of the cheek.
Dr. Shalini Prasad said, “Even here in Texas, where marijuana is not yet legal, the conversation has already started. Do we have technologies that, if you do a rapid screen at a roadside stop, can determine THC levels accurately? The effects of marijuana vary so much from person to person. There’s significant research on how its metabolism works. But determining how it works on the general population across various demographics is difficult—much more so than for alcohol.”
Saliva testing allows the device to determine the electrochemical signal of THC metabolites in a person. The strength of the signal reflects the amount of THC in one’s saliva.
Blood and urine samples can both be inaccurate when testing THC metabolites, whereas, saliva testing can be much more accurate.
Dr. Prasad said, “We’ve shown with 95% accuracy the correlation between salivary concentration and blood concentration of THC.”
Further research and development are needed before the new THC saliva testing devices are used by authorities.