Controlled positioning of a DNA molecule in an electrode setup based on self-assembly and microstructuring

Single-molecule manipulation provides a valuable tool for the characterization of biological processes on the molecular scale. The techniques are usually based on microscopical methods; typical examples are optical tweezers and scanning probe techniques. They need sophisticated equipment and usually handle only one molecule at a time. In contrast to these established serial manipulation methods, techniques for the parallel manipulation of individual molecules are still in development. Here we describe an approach to place single molecules at a defined position on a microstructured surface based on self-assembly steps. Using DNA molecules with lengths in the micrometre range on microstructured surfaces, the defined immobilization of one DNA molecule spanning the gap between microelectrodes is demonstrated by scanning force microscopy. In principle, the described self-aligning approach should also work in a parallel manner. It opens the way for access to the molecular world with high throughput and without the need for ultramicroscopical setups.