Gold Nanowire Electrode Arrays: Investigations of Non-Faradaic Behavior

In this paper we explore large non-faradaic contributions occurring at individual nanowire electrodes and nanowire array devices. We report fabrication of well-defined individual gold nanowires and nanowire arrays at silicon chip substrates via hybrid E-beam/photolithography. Nanowire electrodes and their arrays exhibit good electrical conductivity. We demonstrate highly reproducible sigmoidal, quasi-steady-state voltammograms at nanowire arrays in the model redox probe hexaminoruthenium (III) chloride. We observe large, unexpected contributions in measured non-faradaic or capacitive currents at these nanowire devices. We undertake experimental analysis in the absence of redox active molecules and demonstrate through finite element simulations, that these increased capacitive signals may be caused by a buildup of charged species at the insulated buried metal interconnection tracks. (C) 2013 The Electrochemical Society. All rights reserved.