Eureka!: Small Wonders

A Breathalyzer for Cocaine?

image of a gold and silver nanoparticles.

Photo: Nan Zhang

By Charlotte Hsu


Gold and silver nanoparticles coat the surface of a chemical-sensing chip in a pattern reminiscent of Van Gogh’s starry skies. This visually appealing architecture is a powerful tool: The nanoparticles work with other parts of the chip to trap light, which then scatters into unique, identifiable energy signatures when different chemicals land on the chip’s surface. In experiments, UB electrical engineer Qiaoqiang Gan and colleagues used this method to identify cocaine in minutes. Next up, the team hopes to integrate the technology into portable detectors that can pinpoint cocaine, marijuana and other drugs. Such devices—long on the wish list of law enforcement—could help curb dangerous driving and make it easier to monitor drug use.