Electrodeposition of long and well-defined gold nanotubes in polycarbonate (PC) templates is still a major concern due to pore blockage problems. In the present study, we introduce a novel method for electrode-position of long gold nanotubes within the pores of PC templates for the first time. In order to deposit gold atoms onto the pore walls preferentially, pore walls were functionalized with a coupling agent. Short and thin Ni nanotubes were then electrodeposited at the bottom of the pores. Gold nanotubes were subsequently electrodeposited at constant potentials and low solution concentrations. The morphology of nanotubes was characterized by electron microscopy and their formation mechanism was discussed in detail. Gold nanotubes were fabricated inside PC template with different lengths even as long as the template thickness which was about 6 mu m. Using controlled chemical etching of PC template, three-dimensional gold nanoelectrode ensembles (3D GNEs) were developed which show much higher sensitivity compared to their embedded GNEs counterparts in the presence of Fe2+/Fe3+ redox couple. Cyclic voltammograms show that the sensitivity of 3D GNEs increases with increasing the number of etching cycle. (C) 2012 Elsevier Ltd. All rights reserved.