Another new product that's not yet on the market could potentially have as dramatic an impact on toxic emergency response as Pyrocool has on extraordinary fires.

Researchers at the Department of Energy's Los Alamos (N.M.) National Laboratory have adapted the way cells naturally communicate with each other, packaging it in a sensing technique that's useful in the early detection of toxins.

At present the technique only detects the toxin created by the cholera bacterium, but the technology has been proved and what remains is detail. The new sensor is expected to work equally well at detecting other biological toxins, such as those that could be released by terrorist activity.

First responders may find the new fast-acting, highly sensitive detector vital in quickly identifying and minimizing the impact of terrorist attack. The method sniffs out specific proteins against an ocean of background molecules by mimicking the natural cell signaling processes. This is similar to our own sense of smell, in which a single recognition event triggers a cascade of signals.

According to lead researcher Basil Swanson, lanl Chemical Science and Technology Division, there's currently no such hand-held sensor that can be operated by a first responder. (This shouldn't be confused with the lab-based instruments currently available for the detection of pathogens or toxins.) "The closest thing is the Biological Integrated Detection System that the Army has, which is a Humvee with a bunch of instruments in it," he said.

What this development makes possible is the potential for a small sensor system that could be used in the field to detect a variety of protein toxins or signature proteins of pathogens.

Swanson stresses that the work is preliminary and that so far they have only developed this method using a relatively bulky instrument called a flow cytometer. "It will take time for us to adapt this to a real sensor system," he said. "Also, you should note that we have demonstrated this for cholera and need more time to adapt to other infectious diseases or pathogens that a terrorist would use."

The researchers say the system is similar to the way nature designed the sense of smell in vertebrates. "The most important thing is that a very specific recognition event, the binding of a receptor molecule by the protein toxin, generates the signal that we use to sense the presence of the toxin," said Swanson. "Amplification of this signal then amplifies both sensitivity and specificity."

Although toxins have different mechanisms for how they work, they always recognize receptor molecules on the surface of a cell membrane. This work simply duplicates the receptor molecule and the membrane and attaches them to the surface of a sensor device.

"Certainly this could be used as an environmental detector for selected biological toxins or signature proteins of pathogens," Swanson said. "For example, first responders could use this to detect the presence of toxins or signature proteins. Of course, this could be adapted for military use as well, and this can be done immediately using the flow cytometer that is part of the bids."

Several issues remain before the device finds its way into the arsenal of emergency crews. "First, we need to adapt this approach to other important infectious diseases or toxins," Swanson said. "Each different toxin is a study in its own right. Although the approach is quite flexible, we must use the best receptor for that particular toxin or protein, and sometimes this is a big unknown. It will take some time."

The second area of future work is to adapt the technology to a miniaturized sensor array system. This is not a matter of if, Swanson said, but when. "Others have done similar things for immunoassay approaches. It is a matter of time and a matter of how sensitive the integrated sensor systems will be."