Controlling the optical behavior of molecules near the vicinity of noble metal nanoparticles continues to be an active research area in nanoscience. A molecular level understanding of the optical properties of such metal-molecule complexes is important for many applications such as energy harvesting, nanoscale optical circuits, and ultra-sensitive chemical and biological sensors. In this talk we will discuss our recent theoretical studies aimed at understanding the coupling between molecules and plasmons.

Electrically switchable DNA layers for the label-free detection and sizing of protein targets on a chip Ulrich Rant Walter Schottky Institute, Technical University Munich We introduce a chip-compatible scheme for the label-free detection of proteins in real- time that is based on the electrically driven conformation-switching of DNA oligonucleotides on metal surfaces. The switching behavior is a sensitive indicator for the specific recognition of IgG antibodies, antibody-fragments, and small proteins, which can be detected in quantities of less than 1 amol on the sensor surface.