Transistor behavior via Au clusters etched from electrodes in an acidic   gating solution: metal nanoparticles mimicking conducting polymers
  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. 
Jacob E. Grose, Burak Ulgut, Abhay N. Pasupathy, D. C. Ralph and   Hector D. Abruna