Abstract: The combination of template synthesis method of nanowire/nanotube and conductive atomic force microscopy (C-AFM) is an efficient way that can be used to probe the conductivity of single one-dimension nanomaterial and its array. This communication reports the conductivity of an electrochemically prepared single polyaniline (PANI) nanowire determined using C-AFM and dependences of the conductivity on its diameter and redox state. Our preliminary results of measured current-voltage curves show that the volt-ampere characteristic is similar to that of semiconductor, except that reverse breakdown characteristic has not been observed in the bias range of our test. The possible reason is that the conducting partial oxidized state is reduced into insulating reduced state under the applied reverse bias. The conductivity is lineally increased while the decrease of the diameter of nanowire. Meanwhile, the conductivity of oxidized state and reduced state doped with ClO₄^－ ion is lower than that of partial oxidized state by two order of magnitude.

Key words: Polyaniline, Single nanowire, C-AFM, Conductivity