Characterization of molecular electronic transport is an active part of the
research field in nanotechnology. The main underlying idea is to use single
molecules as active elements in nanodevices [1]. As a consequence, the
proper fabrication of a molecule–electrode contact is a crucial issue
[2],[3] and several applications can be envisioned. For example, the
variation of the electrical conduction of metal–molecule–metal
junctions can be used in biosensing for electrochemical detection of
different crucial biomarkers. Possible applications include biomedical
diagnostics and the monitoring of biological systems. In particular, the
detection of single proteins might become the starting point for monitoring
drugs, developing clean energy systems, fabricating bio-optoelectronic
transistors, and developing other innovative devices and systems.
The fabrication of nanogaps
Nanogap electrodes (NGEs, defined as a pair of electrodes separated by a
nanometer-sized gap) are fundamental tools for characterizing the electric
properties of material at the nanometer scale, or even at the molecular
scale. They are also important building blocks for the fabrication of
nanometer-sized devices and circuits.
Molecular-based devices possess unique advantages for electronic applications
with respect to conventional components [4], such as lower cost, lower power
dissipation and higher efficiency. Specific molecules can be not only
recognized, but also self-assembled on such NGEs, thus leading to elaborate
geometries for the study of distinct optical and electronic properties.