Thwarting Terrorism: Lasers and enzymes detect and destroy airborne toxins
Two research groups at Princeton are harnessing the power of lasers to detect airborne dangers, including anthrax and toxic gases. A third program aims to mass produce enzymes that swiftly degrade potentially lethal nerve agents.
The multimillion dollar Mid-Infrared Technologies for Health and the Environment center, funded by the National Science Foundation and directed by electrical engineering professor Claire Gmachl, is developing state-of-the-art sensors that will detect trace amounts of dangerous substances in the air. Led by Anthony Hoffman, a graduate student in Gmachl’s lab, MIRTHE researchers recently invented a new type of material that could be used in very compact sensors that monitor the air in high-risk locations, such as airport terminals.
In 2007, another research group, at Princeton and Texas A&M University, reported in the journal Science a laser technique to detect anthrax in less than a tenth of a second. Using a series of laser pulses, the technique identifies anthrax based on how spores of the dangerous bacteria scatter light and works even in the presence of other substances. “We do our experiments ‘on the fly,’ so we can get a reading within a tiny fraction of a second,” said lead author Marlan Scully, who holds joint appointments in Princeton’s Department of Mechanical and Aerospace Engineering and the physics department at Texas A&M. The work was supported by the Welch Foundation, the Office of Naval Research and the Defense Advanced Research Projects Agency.
In addition to superior detection capabilities, national security relies on technologies that can destroy bioterrorism agents after they are found. David Wood, an assistant professor of chemical engineering, is designing a process to rapidly and inexpensively produce large quantities of a substance that offers protection from nerve gas.
The protectant—an enzyme that breaks down organophosphate chemical bonds found in nerve agents—can be made by bacteria and yeast, but current techniques to purify the substance are prohibitively expensive. Wood’s work, funded by the U.S. Army, aims to link the lifesaving enzyme to a protein “tag” that can be isolated from solution using a series of simple temperature and pH changes. This tag can then be easily cleaved off, leaving behind the purified enzyme.
“The goal is to develop a process that is essentially self-purifying,” Wood said.