  We report that the electrical conductance between closely-spaced gold
electrodes in acid solution can be turned from off [insulating; I] to on
[conducting; C] to off again by monotonically sweeping a gate voltage applied
to the solution. We propose that this ICI transistor action is due to an
electrochemical process dependent on nanoparticles etched from the surface of
the gold electrodes. These measurements mimic closely the characteristics of
nanoscale acid-gated polyaniline transistors, so that researchers should guard
against misinterpreting this effect in future molecular-electronics
experiments.
