Electrical transport and chemical sensing properties of individual conducting polymer nanowires.

The electrical transport and chemical sensing properties of individual multisegmented Au-poly(3,4-ethylenedioxythiophene)(PEDOT)-Au nanowires have been investigated. Temperature dependent conductivity measurements show that different charge transport mechanisms influence these properties in two types of PEDOT nanowires. Charge transport in PEDOT/poly(4-styrenesulfonic acid) (PSS) nanowires is in the insulating regime of the metal-insulator transition and dominated by hopping, while PEDOT/perchlorate (CIO4) nanowires are slightly on the metallic side of the critical regime. The vapor sensing properties of individual nanowires to water and methanol reflect the fact that the two kinds of PEDOT nanowires operate in different transport regimes. Nanowires in the metallic transport regime show much greater sensitivity to vapor-phase analytes than those in which transport is dominated by hopping.