Exploring the Properties of Individual DNA Molecules
By employing the Low Energy Electron Point Source (LEEPS) microscope, it has
been possible to probe the electrical conductivity of individual DNA molecules.
Our current efforts are directed towards interfacing these bio-polymers to
micro- or nano-fabricated silicon structures to built novel molecular electronic
devices. A close collaboration with Clondiag Chip Technologies GmbH in Jena
enables us to make use of their state of the art bio molecular technologies
to specifically anchor individual molecules on silicon devices. Understanding
the conduction mechanism in DNA molecules and making use of it in molecular
devices are the ultimate goals of this endeavour.A second objective of our
single molecule studies is less applied. It relates to fundamental questions
in polymer physics as well as to the biological function of DNA in its natural
liquid environment. The tools and methods mentioned above have enabled us
to directly observe the dynamics of single DNA molecules in liquids by video
fluorescent microscopy. In combination with the molecular anchoring techniques,
adopted from Clondiag, we were able to address the energetics of a single
DNA molecule. Measurements of the activation free energy associated with the
transition from the stretched to the random coil configuration have been carried
out. The statistics of these thermo dynamical data as well as the temperature
range of these measurements is currently expanded in order to end up with
quantitative and statistically reliable energy values.
Contacts: Conrad Escher, Hans-Werner Fink
Supported by:
Swiss National Science Foundation
Clondiag Chip Technologies GmbH, Jena (Germany)
Further reading:
Manipulating individual lambda-DNA molecules in aqueous solution Diploma Thesis, Conrad Escher, December 2001 (PDF file: 2.50 MB)
DNA
and Conduction Electrons Hans-Werner Fink; “Visions and Reflections
Article” in Cellular and Molecular Life Sciences 58 (2001) 1-3
Birkhäuser Verlag Basel (PDF file: 64 KB)
Electrical conduction through DNA molecules H.-W. Fink and Ch. Schönenberger, Nature 398, (1999), 407 (PDF file: 3.17 MB)