Adv. Mater. doi:10.1002/adma.200904005 (2010)

Carbon nanotubes are finicky materials: the slightest exposure to another chemical can alter their ability to conduct electricity.

Chongwu Zhou and his colleagues at the University of Southern California in Los Angeles have taken advantage of this property to create an explosives sensor that can be transferred to cloth. Zhou's team made sheets of carbon nanotubes, stuck them to fabric and then exposed them to chemicals such as 2,4,6-trinitrotoluene (TNT) and nitrogen dioxide (NO2).

The group recorded changes in conductance at low concentrations of the chemicals: 40 parts per billion (p.p.b.) of NO2 and 8 p.p.b. of TNT. The team achieved similar results with zinc oxide nanowire sensors and TNT. The sensitivities of these methods are not as high as those of other detection techniques, but the size and flexibility of the fabric-based sensor could make it useful, the authors say.