Qiaoqiang Gan, PhD, associate professor of electrical engineering in the University at Buffalo School of Engineering and Applied Sciences says currently, there is a great demand for on-site drug testing, and the high-performance chip they designed is able to detect cocaine within minutes. An inexpensive that can be produced using raw materials that cost around 10 cents.
Gan developed the new chip with a team that included first authors Jun Gao, a research associate of Material Sciences at Fudan University in China, and Nan Zhang, a PhD candidate at the University of Buffalo, along with colleagues from the UB Department of Electrical Engineering; the UB Research Institute on Addictions; and the UB Department of Community Health and Health Behavior in the UB School of Public Health and Health Professions.
The new chip is an engineered nanostructure that traps light at the edges of gold and silver nanoparticles. When biological or chemical molecules land on the chip’s surface, some of the captured light interacts with the molecules and is “scattered” into light of new energies. This effect occurs in recognizable patterns that act as fingerprints, revealing information about what compounds are present.
Because all chemicals — cocaine, opioids, and active ingredients in marijuana — have their unique light-scattering signatures, researchers can use the technology to quickly identify a wide range of chemicals.
This sensing method is called surface-enhanced Raman spectroscopy (SERS), and it’s not new. But the chip that Gan’s team developed is noteworthy for its high performance and low cost.”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,” Zhang says. “The chips used for SERS are typically fabricated using expensive methods, such as lithography, which creates specific patterns on a metal substrate. The chip was created by depositing various thin layers of materials on a glass substrate, which is cost-effective and suitable for industrial-scale production.