Rapid measurement of single-molecule conductance.

A new device for measuring the conductance values of single-molecule junctions which are covalently bound to two electrodes is presented. The system works by repeatedly bringing two electrodes into and out of contact in a solution of molecules while measuring the current between the two electrodes during withdrawal. When molecules connect the two electrodes, steps occur in the current transient, and a statistical analysis provides the most probable conductance value for a single-molecule junction. This system provides an order of magnitude increase in speed over previous devices used for single-molecule conductance measurements, and the applicability of this tool is demonstrated in array based measurements as well as in biologically relevant samples where the conductances of single amino acid residues are measured.