MAKING ELECTRICAL CONTACT TO SINGLE MOLECULES

We are interested in the characterization of electron transport phenom enon through single (bio)molecules. A prerequisite for electrical meas urements is the contacting of molecules in the nanometer range. This p aper describes various steps toward this goal, starting from statistic ally distributed molecules (namely, microtubules) adsorbed on a micros tructured surface. Monitored by scanning force microscopy and video-en hanced microscopy, adsorption parameters were studied and optimized, i ncluding protein-mediated adsorption, induced orientation, and control led desorption. Line structures connecting the adsorbed molecules to p restructured electrodes were created by means of electron beam-induced deposition (EBD) in a scanning electron microscope. It is shown how s uch EBD lines can be used as masks for the structuring of metal contac ts, and an electrical characterization of these contacts is given.