Roland Piquepaille writes "A substance found in crab shells called chitosan has very useful properties. For example, it has been used in bandages to stop bleeding. But now, researchers at the University of Maryland have used the chitosan from blue crabs living in Chesapeake Bay as a component of a nanoscale sensor system which could save many lives in the future. These blue crab nanosensors will be used to improve security in airports, hospitals and other public locations by detecting tiny amounts of explosives or chemicals in air and water. Read on for additional references and pictures of these blue crab nanosensors."