A metalized microtubule yielded a resistance below 50 Ohm over the length of one micron. A prerequisite for electrical measurements is the wiring of the small structures, which represents enormous technical challenges due to the usually random distribution and the small feature size. A variety of techniques was developed to wire molecular structures dispersed on a planar substrate. A dry-etching step removes the gold coating except the masked region below the lines. The presented paper extends this work by demonstrating electrical measurements.
Electrical measurements demonstrate the successful realized wiring of the metallized biomolecules.
Briefly, the protein structures were activated by adsorption of Pt-catalyst particles using K2PtCl4 solution, followed by a metalization using Ni acetate. Deposition onto the substrate A droplet of diluted metallized microtubule solution was placed on the prestructured substrates containing microelectrodes for approx. Then, excess water was removed with filter paper, and the specimen air-dried. This process is limited by surface diffusion. The gold was removed by dry etching using Ar ions.