Metal nanoparticles are structures with interesting optical and electronical properties. Due to the small size, defined manipulation of these particles (e.g. positioning) is difficult. To overcome this problem, self-assembly processes based on bioconjugated nanoparticles and surfaces were proposed.

We develop techniques for specific positioning of individual nanoparticles on electronic chip surfaces using complementary DNA (1). As an example for possible electronic applications, a scheme and first realized steps towards a single-electron tunneling transistor using this approach will be presented. This includes the positioning of individual molecules of lambda-DNA in an electrode gap.

Beside such rather far-reaching visions, DNA-nanoparticle complexes have an interesting application already today as potential complement (or maybe even replacement) label in DNA chip technology. Work towards an optical (2) and electrical (3) detection of nanoparticle DNA on a solid substrate demonstrated the feasibility of this approach. An electrical detection system based on a resistive principle, using a microstructured chip with a DNA array, nanoparticle-labeled DNA and an autonomous readout device, was realized (4).