Carbon nanotubes: A thermoelectric nano-nose

A thermoelectric 'nano-nose' has been built from tangled bundles of single- walled carbon nanotubes (SWNT). The response is specific to the details of the interaction of the adsorbed molecule with the nanotube wall; even gases such as He, N-2 and H-2 can be easily detected. Plots of DeltaS vs. rho (a ) are sensitive to whether oxidation or reduction of the tube wall is takin g place, and to whether the gas molecule is physisorbed or chemisorbed. (C) 2001 Elsevier Science B.V. All rights reserved.