DARPA seeks proposals to improve bio-threat detectors

The Defense Advanced Research Projects Agency is requesting proposals for a device that would enable faster, more accurate detection of a broad range of biological agents, writes Katie Drummond of Wired.com. DARPA hopes to create a biosensor that would identify viral and bacterial threats, and do so using a natural first-line of defense: human antibodies.

Infectious microorganisms are on the rise, and the Pentagon is in a rush to develop better detection, treatment, and even all-out prevention. With a need for quick response, it is no surprise that DARPA, the military’s mad-science division, is playing a major role in combating bioterrorism attacks and natural threats like H1N1.

According to DARPA’s new solicitation, antibody biosensors offered the most reliable detection, across the broadest range of bio-agents. Now they want to make the sensors even better.

Drummond writes that DARPA is asking for proposals that would address the two downsides of antibody-based biosensors. Antibody proteins are fragile, so they are unable to withstand extreme temperatures or survive longer than a few weeks in storage. This is not practical for civilian medical centers, let alone a war-zone. DARPA wants the new biosensors to be as resilient as possible.

The body in reaction to a foreign viral or bacterial threat, called an antigen, produces antibodies. A particular antibody can only bind to a single antigen, but science has already created antibodies that can bind to several different ones. Now, DARPA wants them to have a more diverse “affinity level”: the ability to bind to a potentially endless array of viral or bacterial antigens. The tip of an antibody is extremely variable, which is why different antibodies attach to different antigens. It is this binding that is used by biosensors to identify various microorganisms, and distinguish between them. DARPA wants to control, or “fine-tune” antibody affinity, so that one “master antibody” can bind with millions of antigens.

DARPA’s request is not specific about how they expect the master antibody, and its accompanying biosensor, to be created. Artificial antibodies have been in the making for years, offer a cheaper, more easily manipulated platform, and are becoming more reliable thanks to new technology.

Also, researchers at Portland State University have already manufactured a hand-held antibody biosensor, so chances are good that the detection of biothreats will look cooler than a throat swab, too.