DNA Nanodevices

The work undertaken in this unit focuses on developing diagnostic and therapeutic applications of nanomaterials constructed by methods such as DNA self-assembly and molecular programming. Founded in 2013 as a part of the Fraunhofer Attract program, the unit’s aim is to develop concrete DNA-based tools for research and biomedicine, as well as to investigate and exploit the underlying material properties of nanoparticles built from DNA and composites. One aspect centers on the ability of DNA-based templates to serve as precise guides for the nanometer-scale arrangement of basic components for biosensors and nanocircuitry. Additionally, the unit develops functional platforms from DNA and other materials for the efficient transport of molecules in vitro and in vivo. Mechanical properties of DNA platforms as well as emergent properties from composites are also examined as possible instruments to increase the functional nature of hybrid materials.

DNA self-assembly and molecular programming

Currently, the most advanced method for the programmed assembly of nanometer-sized objects with well-controlled shapes and surface features uses DNA hybridization. Techniques like the DNA origami method or DNA “bricks” use the simple rules of complementary base pairing and placement of branched “Holliday” junctions between three or more DNA strands to generate complex two- and three-dimensional shapes. This enables DNA to serve as a highly programmable structural building block while stepping outside of the role of being the blueprint for cellular structure. Computer-assisted tools such as caDNAno and newly developed techniques for lab desk automation facilitate the rapid and precise creation of objects of virtually any shape on the nanometer scale.

Atomic Force Microscopy

Atomic Force Microscopy (AFM) is a tool for gaining precise structural and mechanical information about materials on a molecular scale. By scanning materials with a sharp tip just a few atoms in width, structural features can be resolved down to nanometer resolution. Furthermore, AFM-based force spectroscopy also allows the measurement of forces down to single piconewtons, and the local elastic properties of biological materials such as gels, cells and many more.

Transmission Electron Microscopy

Transmission Electron Microscopy (TEM) is a microscopic technique that utilizes an electron beam, rather than light to view objects down to the scale of a few nanometers. Due to the diffraction limit for imaging systems, typical light and fluorescent microscopes cannot resolve features below approximately one micrometer. Accelerated electrons have a far smaller wavelength, and therefore can reduce the diffraction limit by several orders of magnitude.

Carbon nanostructure functionalization

Single-walled carbon nanotubes (SWNT) display a number of outstanding properties that have led them to be considered promising materials for transistors, sensors, drug delivery, energy storage, antimicrobial agents and many more. However, the ability to use SWNTs in the multitude different application is highly dependent on their ability to stably interface with other materials. In our group, different materials such as DNA, short polypeptides, proteins, surfactants and more are used to create the ability to integrate nanotubes into different functional applications.

  • DNA-based templating of functional carbon nanostructures for biosensors and nanocircuitry
  • Development of molecular carrier and immunological systems from DNA and hybrid materials
  • Energy conversion and ordering phenomena in DNA-based and composite nanomaterials
  • Mechanical characterization of DNA-based and composite nanomaterials

  • University of Cologne, Faculty of Mathematics and Natural Sciences, Department of Chemistry, Institute for Biochemistry
  • pluriSelect GmbH
  • University of Leipzig, Faculty of Veterinary Medicine, Institute for Veterinary Anatomy
  • Chemnitz University of Technology, Department of Electrical Engineering and Information Technology, Center for Microtechnologies
  • LMU Munich, Faculty of Physics, Chair for Experimental Physics: Soft Condensed Matter
  • Yale University, Yale School of Medicine, Department of Molecular Biophysics and Biochemistry
  • TU Dresden, Biotechnology Center

  • Nickels PC, Ke Y, Jungmann R, Smith DM, Leichsenring M, Shih WM, Liedl T, Högberg B. DNA origami structures directly assembled from intact bacteriophages. Small. 2014 May 14;10(9):1765-9. DOI dx.doi.org/10.1002/smll.201303442.
  • Smith DM, Schüller V, Engst C, Rädler J, Liedl T. Nucleic acid nanostructures for biomedical applications. Nanomedicine, 2013. 8(1): p. 105-121.
  • Smith DM, Schüller V, Forthmann C, Schreiber R, Tinnefeld P, Liedl T. A structurally variable hinged tetrahedron framework from DNA origami. J. Nuc. Acid., 2011. DOI dx.doi.org/10.4061/2011/360954.