Scientists have created a new chemical sensing chip which could become the core of effective and quick drug detection technologies in the future.
The team of researchers from the University of Buffalo says the chip is an engineered nanostructure coated in gold nanoparticles deposited over silver nanoparticles.
Light is trapped at the edges of the particles, and when biological or chemical elements land on the chip's surface, the light interacts with these compounds.
The light then scatters, revealing what chemical molecules are present. Recognizable patterns give users clues in the same way as fingerprint scanning.
According to the scientists, the chip could be used in equipment to test for drug use as quickly efficiently as our current roadside breathalyzers, which are used to check alcohol intake.
The chip encompasses horizontal layers of material laying on top of each other. Sheets of dielectric material, such as silicon dioxide and aluminum oxide, are sandwiched between silver which acts as the base of the hardware. The surface then hosts the active gold and silver nanoparticles.
During tests with cocaine, the invention was able to detect the illegal substance "within minutes," according to the researchers.
The sensing method is known as surface-enhanced Raman spectroscopy (SERS). While not new, when applied to chemicals -- which all give off unique light-scattering signatures -- SERS can provide quick chemical detection.
However, SERS hardware is usually expensive, and so the challenge was to make the sensing chips affordable to easy to mass-produce.
The team says that due to how the material has been put together, the chip could be produced for as little as 10 cents.
If the design ends up going commercial, law enforcement officers could one day find themselves equipped with handheld devices able to detect not just alcohol, but a wide range of drugs.
The next step in the research project, however, is the installation of the chip into portable devices which are able to collect blood, breath, urine, or saliva, extract any molecules related to drugs, and then send them to the chip for reliable testing.
"Currently, there is a great demand for on-site drug testing," says Qiaoqiang Gan, associate professor of electrical engineering in the University at Buffalo School of Engineering and Applied Sciences and author of the study. "In the future, we are hoping to use this technology to detect [other] drugs, including marijuana."
"The widening legalization of marijuana raises a lot of societal issues, including the need for a system to quickly test drivers for drug use," Gan added.
The study was funded by the National Science Foundation and has been published in the academic journal Small Methods.
In April, researchers from the University of California San Diego revealed the development of a chip which, when embedded under the skin, can monitor alcohol levels in the blood.