On guard: Sentinel plants could warn of bioterror

U.S. soldiers walk down a trail in a war zone. One of them pulls out a hand-held electronic device and points it at a native plant. The readings on the device indicate the plant was exposed to nerve gas sometime in the last 48 hours, allowing the soldiers to don protective gear before they suffer a lethal dose. Although such a device does not exist, it’s not as far-fetched as it may sound. As concerns grow over the threat of bioterrorism and weapons of mass destruction, university researchers are working on an early warning system — the figurative canary in the mineshaft — that could be as unobtrusive and ubiquitous as plants in a landscape.

Tiny Cell-Based Chemical Detectors Have Protection Potential

A highly sensitive, inexpensive “lab-on-a-chip” that provides warning within seconds of even trace amounts of toxic chemicals in water was designed and demonstrated recently by National Institute of Standards and Technology (NIST) scientists and collaborators. The prototype sensor system monitors the natural response of bacterial cells bound within the microscopic channels of a plastic microfluidics device — a miniaturized chemical and biochemical analysis system. In the presence of certain chemicals, the cells eject large amounts of potassium, which is detected with an optical sensor that changes color. The prototype was demonstrated as part of an early warning system for industrial pollutants that interfere with sewage treatment, but it also has potential homeland security applications.