We have acquired a home-built STM to single-molecule conductance measurement using the break-junction technique in air.
This technique allows to stablish atomic-size contacts between two metal electrodes by a pull and push process. When the molecules of interest are deposited on one of the electrodes, some of them could be attached between the electrodes throughout the pull process, creating momentary molecular wires which can be used to measure the conductance of these single-molecules.
In our case, the STM tip and substrate play the role of the electrodes of the break-junction device, both in Au because of it inertness. In order to ensure a good molecule-electrode contact, anchoring groups, such as amines or thiols, must be included in the structure of the molecules.
