A 10-Cent Metal Chip May Be The Next Big Thing In Drug Testing

By Keri Blakinger 05/14/18

The chip's developers are hopeful that one day the technology will be used to detect marijuana use.

Microchip on a fingertip

A tiny, cocaine-detecting chip could be the wave of the future when it comes to roadside drug tests. 

This month, a team of researchers at the University at Buffalo published a paper detailing a method of chemical testing that uses a light-trapping nanostructure to identify tiny samples of chemicals. And, though it’s been tested to target cocaine, scientists are optimistic it can be used with a wide array of other drugs in the future. 

“Currently, there is a great demand for on-site drug testing,” said Qiaoqiang Gan, a Buffalo professor and one of the paper’s authors. “The high-performance chip we designed was able to detect cocaine within minutes in our experiments. It’s also inexpensive: It can be produced using raw materials that cost around 10 cents, and the fabrication techniques we used are also low-cost.”

Basically, the futuristic tech works by catching light at the edge of gold and silver nanoparticles. Those nanoparticles scatter the rays into specific recognizable patterns that are unique to specific substances. The technique of using “light-scatting signatures” to identify chemicals is known as surface-enhanced Raman spectroscopy, or SERS. That in and of itself isn’t new—but what’s new is Gan’s “high performance and low cost” chip. 

“SERS holds a lot of promise for rapid detection of drugs and other chemicals, but the materials required to perform the sensing are usually quite expensive,” said Nan Zhang, another of the study’s authors. “The chips used for SERS are typically fabricated using expensive methods, such as lithography, which creates specific patterns on a metal substrate. We created our chip by depositing various thin layers of materials on a glass substrate, which is cost-effective and suitable for industrial-scale production.”

The chips last a long time, with a shelf life long enough to still work well after a year in storage. That’s in part because of a design that incorporates gold nanoparticles to help shield the silver from oxidizing. 

To make the tiny chips practical for use, they’ll have to be installed in some sort of portable testing device. Then, police would be able to carry them around and use them to run blood and breath tests to check for the presence of cocaine or other drugs.

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Keri Blakinger is a former drug user and current reporter living in Texas. She covers breaking news for the Houston Chronicle and previously worked for the New York Daily News and the Ithaca Times. She has written about drugs and criminal justice for the Washington Post, Salon, Quartz and more. She loves dogs and is not impressed by rodeo food. Find Keri on LinkedIn and Twitter.