After blood, urine or hair, it is with the consumer's breath that we will detect cannabis
A team has developed a breathalyzer capable of measuring the amount of tetrahydrocannabinol (THC) in the user's breath. The breathalyzer was developed using carbon nanotubes, tiny tubes of carbon 100 times smaller than a human hair. Nanotechnology sensors can detect THC at levels comparable to or better than mass spectrometry, which is considered the gold standard in THC detection.
As recreational legalization becomes more prevalent across the United States, there are also concerns about what this means for the app. drunk driving laws. Unlike the “breathalyzer” breathalyzer used to detect the presence of alcohol, the police do not have a device that can be used in the field to determine if a driver is under the influence of cannabis. New research from the University of Pittsburgh is about to change that.
A team Interdisciplinary Department of Chemistry and Swanson School of Engineering has developed a breathalyzer that measures the amount of tetrahydrocannabinol (THC), the psychoactive compound, in the consumer's breath. Current drug testing methods rely on blood, urine or hair samples and therefore cannot be performed in the field. They also reveal that the user recently inhaled the drug, not that he is currently under the influence of alcohol.
The breathalyzer was developed using carbon nanotubes, tiny tubes of carbon 100 times smaller than a human hair. The THC molecule, along with other molecules in the breath, binds to the surface of nanotubes and changes their electrical properties. The speed at which the electric currents are restored then indicates whether THC is present. Nanotechnology sensors can detect THC at levels comparable to or better than mass spectrometry, which is considered the gold standard for THC detection.
Their research took place under the supervision and with the permission of the US Drug Enforcement Agency.
“The semiconductor carbon nanotubes we use were not available a few years ago,” says Sean Hwang, senior research author and PhD candidate in chemistry at Pitt. We used machine learning to "teach" the breathalyzer to recognize the presence of THC based on the recovery time of electrical currents, even when there are other substances, such as alcohol, present in the breath. .
Hwang works at the Star Lab, headed by Alexander Star, PhD, professor of chemistry with a secondary appointment in bioengineering. The group partnered with Ervin Sejdic, PhD, associate professor of electrical and computer engineering at the Swanson School of Engineering, to develop the prototype.
“Creating a prototype that works in the field was a crucial step in the application of this technology,” explains Dr Sejdic. “It took an interdisciplinary team to turn this idea into a usable and vital device for road safety. "
The team took three years to develop a portable model of the device that could be used in the field.
The prototype looks like a breathalyzer for alcohol, with a plastic casing, a protruding mouthpiece and a digital display. It has been tested in the lab and shown to be able to detect THC in a breath sample that also contained components like carbon dioxide, water, ethanol, methanol, and acetone. Researchers will continue to test the prototype, but they hope that it will soon be put into production and ready for use.
In legal states, you'll see road signs that say “If you're high drive safely,” but there hasn't been a reliable and practical way to enforce that, ”says Dr. Star.
“There are debates in the legal community about what THC levels would amount to impaired driving. The creation of such a device is an important first step to ensure a true screening of THC “.
While law enforcement can draw on years of research to document blood alcohol levels in impaired driving, there is little such research on THC.
In a report presented to Congress in 2017, the National Highway Traffic Safety Administration acknowledged that there is little research data available on drivers impaired by cannabis and the level at which impairment begins. Star said it will allow researchers to begin work on determining when and at what level of THC the spoilage begins.
It probably also depends on the rate of use and the size of the person. The presence of THC in the breath does not mean that the person may be weakened, ”Star says. “We will try to measure this in future research.