We are developing novel methods to investigate interactions between biomolecules, employing electrically switchable DNA layers, nanoparticle plasmonics, and solid state nanopore sensors. During the course of the project, we were able to lay the scientific foundations for the controlled electrical manipulation of DNA molecules on surfaces, which constitute the basis for the “switchsense” principle. The application of the switchsense method for the detection of DNA and proteins was published in high-impact journals such as PNAS, Nano Letters, JACS, and others. Special attention was given to the unique feature of the switchsense method, namely, the molecular dynamics analysis of the DNA switching process, from which the size or shape of the bound target molecule can be inferred. In 2010 we realized a time-resolved method to measure the switching dynamics on the sub-microsecond timescale, which was an important advancement with respect to the analysis of proteins on a chip. A corresponding patent was filed recently, which adds to the ca. 20 previous patent applications concerning the switchsense technology.

Along with scientific investigations concerning the electrical actuation of DNA layers, we undertook major efforts to design and build various prototypes of electro-optical measurement devices (see figure of a recent version). Additionally, microchip featuring 24 microelectrodes was designed and the chemical functional with several protein receptors was developed.