WASHINGTON -- University of Maryland researchers said that the shell of a crab that is often thrown away may someday save lives.

Researchers Gregory Payne and Reza Ghodssi said that it is the sweet shell that contains a substance called chitosan that acts like a sponge to detect gases.

"I'm coming from the chitosan side, the material side. So we understood and were studying these properties. Dr. Ghodssi was looking at various applications, and really, the hardest part of the whole project was the interface and bringing us together," said Payne.

The interface resulted in a nano-sensor chip that is able to detect deadly materials, like bio-agents, explosives or other dangerous substances in the air or water.

"You could have the sensors positioned in the metro, and the underground, in specific locations -- hundreds of them. They could basically sniff for gasses and tell you if there are any toxic gases in the environment," Ghodssi said.

The researchers used crab shells from manufactures who can the meat. Another processor extracts the chitosan.

In the lab, it coats a what's called a cantilever -- a vibrating pin 100 times thinner than a human hair.

The researchers said the changes in the moving cantilever set off alarms of air or water contamination.

The researchers said they have already sent a proposal to NIH to develop a sensor to detect the presence of Avian Flu.