We present a planar nanogap structure with heterogeneous metal electrodes separated by a distance of tens of nanometers. This asymmetric nanodevice is meant for metal/molecule/metal transport analysis. The heterogeneous aspect of the metal electrodes is meant to trigger the assembly orientation of selected molecules across the gap. With E-beam overlay technique and double-layer passivation, the structure has a well-defined and reproducible gap and shows good chemical durability and dielectric properties. (C) 2011 Published by Elsevier Ltd.s