Scientists are finding uses for natural life forms to deal with modern nasties of all kinds. Just as exotic plant materials yield a wealth of potential medicines, the insect world provides a wealth of sensor servants. I can't wait until the PETA fanatics hear about this one.

One day soon we will be able to look for weapons of mass destruction with weapons of mass infestation.

From the article:

That, at least, is the vision of Jeff Brinker, a materials scientist at Sandia National Laboratories in Albuquerque. Brinker and his team have devised a way to transform the loathed insects into stealthy environmental sentinels to detect chemical or biological agents.

The idea of roach recon isn't as bizarre as it may sound. The Defense Department is already exploring how to use everything from bug-size robots to live wasps for similar tasks. Before warming to the roach idea three years ago, Brinker worked on a Pentagon-funded project to harness honeybees as explosive-sniffing scouts.

Roaches were a natural next step. "It's a very durable beast," Brinker says. "Plus they tend to explore nooks and crannies." But how to put their wiliness to work? The key, Brinker says, is genetically altered yeast cells glued to the bug's body that will glow when they encounter something harmful.

Living cells have several potential advantages over mechanical sensors, says Susan Brozik, a Sandia biochemist working with Brinker. They're small, cheap and exquisitely sensitive to their surroundings.

But sensors made of living cells are difficult to keep alive out in the field, says Brinker.

So the Sandia team coated the cells with Sol-Gel, a liquid material Brinker invented composed mostly of silicon dioxide, or beach sand. The coating hardens into a porous shell only a few nanometers thick. Each pore in the shell stores nutrients to keep the cells perky, and allows the cells to sniff the outside air.

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