University of Texas at Dallas researchers have developed a hand-held rapid saliva test that can measure the level of THC, the major active component in marijuana, with 94% accuracy.
The device, called CannibiSenS, also can distinguish between THC and CBD, a component of the cannabis plant that does not cause a psychoactive effect and is sold legally in dietary substances, creams and other products in most states.
The hand-held rapid saliva test can measure the level of THC, the major active component in marijuana,
with 94% accuracy. The device, CannibiSenS, can distinguish between THC and CBD.
The sensor could be used as a tool for law enforcement officers to test drivers believed to be impaired.
Additionally, medical marijuana practitioners, patients and recreational users might find it helpful to
monitor THC levels, said Dr. Shalini Prasad, professor and department head of bioengineering and a Cecil H. and Ida Green Professor in Systems Biology Science in the Erik Jonsson School of Engineering and Computer Science. Prasad and her colleagues published a study on the technology online May 24 and in the July 7 print edition of the journal Analyst.
“The CannibiSenS device has demonstrated the potential for serving the cannabis community in a manner akin to how glucose monitors help the diabetic community,” said Prasad, who has developed similar technology to monitor glucose levels in sweat. “Ultimately the goal is to provide actionable data with a simple mess-free method.”
Using the device involves taking a saliva sample from inside the cheek with a swab. The sample can be
placed onto the sensor by gently dabbing the swab onto the sensor surface or by using a dropper if the
sample was collected earlier. The electrochemical sensor is more sensitive than over-the-counter tests,
which typically detect THC but do not determine its concentration.
Measuring THC concentration is important, Prasad said, because detectable amounts of the compound
can remain in a marijuana user’s bloodstream for days after use, creating the potential for false positives
in a roadside test, for instance. She said the sensor’s ability to distinguish between THC and CBD also
reduces the chance of false positives.
To test the device’s capability in a real field-test scenario, researchers collected saliva samples from five
people, then spiked the samples with THC before testing the samples with the device. It was accurate
94% of the time.