Drug-detecting chip could be used in breathalyser for cocaine
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Researchers based at the University of Buffalo, New York, have developed a chip capable of testing for cocaine on the spot, which could lead to portable drug detectors for health and law enforcement use.
The chip works using surface-enhanced Raman spectroscopy. It traps light at the edges of gold and silver nanoparticles; when biological or chemical molecules land on its surface, some of this captured light interacts with the molecules, scattering its characteristic energy levels. All chemicals – including recreational drugs – have characteristic energy signatures which can be analysed to identify the compounds.
While the materials normally required to perform this technique are expensive, the Buffalo researchers created their chip by depositing thin layers of inexpensive materials (a dielectric and gold and silver nanoparticles) on a glass substrate: an approach which could be scaled up for mass manufacture. The glass and the dielectric amplify the light to improve detection.
According to the researchers, this technology has a long shelf life and can detect the chemical signature of cocaine within minutes. This could make it ideal as the basis for a ‘breathalyser for drugs’, which could allow for on-site testing for cocaine, opioids and marijuana, all of which could be identified from their distinct chemical signatures.
The chip could be the key component for a handheld, portable device which could quickly detect intoxication from samples such as breath, saliva or urine following a purification process to extract specific molecules for testing.
“Currently, there is a great demand for on-site drug testing,” said Professor Qiaoqiang Gan, an electrical engineer at Buffalo. “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.”
“In the future, we are hoping to also use this technology to detect other drugs, including marijuana. The widening legalisation of marijuana [in the US] raises a lot of societal issues, including the need for a system to quickly test drivers for drug use.”
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