In this study, we investigated a simple glucose biosensor based on a 3D nanostructured gold electrode. The nanostructured gold electrode was fabricated by electrochemical deposition using bulk gold dissolved in aqua regia as the nanogold precursor. Potassium ferricyanide and glucose oxidase were then sequentially coated onto the prepared nanostructure for glucose detection. For the nanostructured electrode, the polarization overpotential for glucose detection was 0.17 V, which is much smaller than that for a plane electrode. An applied potential of 0.7 V was sufficient to generate peak cathodic currents. The peak cathodic and anodic currents for the nanostructured electrode are three orders of magnitude larger than those for a plane gold electrode. The nanostructured electrode shows a fast response time of 1 s. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.035301jes] All rights reserved.