ASU chemical research could benefit airport security

ASU researchers say they have found a way to potentially revolutionize the detection of trace amounts of chemicals, which could improve airport security.

The applications for this technology, which appeared in the March 12 issue of Science magazine, could be far-reaching, potentially including more efficient airport security, environmental data, and analyses of the human body.

Usually the way this is done, called electrochemical detection, is to apply voltage to an electrode, or conductor for a flow of electrical current. Then scientists look for a reaction specific to a particular chemical.

“What’s good about this technique is that by looking at electrical current as a function of applied voltage, you can detect a small amount of molecules very precisely and very quickly,” said N.J. Tao, lead researcher and director of the Biodesign Institute’s Center for Bioelectronics and Biosensors.

However, there are limitations to this method.

“You can sense something taking place on the surface of an electrode, but you can’t tell exactly where the particle is,” Tao said.

The new method his team has developed does not measure the electrode directly, instead taking a “picture” of the whole surface using optical imaging technology.

“That’s very powerful because we can image materials and detect a trace amount of molecules with this imaging technique,” he said. “We have a new dimension, which allows us to resolve the local events. We can simultaneously detect many events within a single electrode.”

This increased precision produced unique results and could have real-world benefits in the field of national security.

“You can image a fingerprint, if it is contaminated with certain materials, such as TNT, it can see a trace amount of this in a fingerprint,” Tao said.

Another of the researchers, graduate student Xiaonan Shan, was the original author of the work.

“We just tried to find an application for [the imaging technology] which is my research interest,” he said.

Shan emphasized the value of this experience to his experience as a research student.

“This was really exciting,” he said. “When I did the research, I didn’t expect the results to be so exciting, but after you do the research and analyze the data and find some interesting results, you feel like you have done something good. That’s the reason I like to do research, because you never know what you will find.”

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