Novel DNA Nanostructures and Detection Systems from Oligonucleotide Containing Hybrid Materials

F. Alemdaroglu, E. Ergen, K. Müllen, and Andreas Herrmann Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany e-mail: andherrm@mpip-mainz.mpg.de URL: http://www.mpip-mainz.mpg.de

We have prepared biological organic hybrid structures consisting of DNA and organic or polymeric materials. Different synthetic strategies for the generation of linear, single stranded DNA block copolymers will be presented. DNA-polystyrene diblock copolymers form a novel type of DNA nanostructures on different substrate surfaces. The dendron-like structures were investigated by scanning force microscopy. Particular characteristics of these structures covering large surface areas of several square micrometers are the straightness and periodicity of the nanoscopic dendritic patterns, bending of rectilinear topologies, and the unidirectional growth of dendrons. Beside linear diblock hybrid structures we synthesized triblock architectures containing single stranded DNA. Two identical oligonucleotide sequences were attached onto a central fluorene emitter. This so called "twin probe" architecture was used for the sequence specific detection of DNA in a homogeneous hybridization assay. Even single nucleotide polymorphisms could be identified very efficiently. The mode of operation of the twin probe assay depending on electron transfer and supramolecular aggregation will be discussed.