Oscillations, Waves, and Interactions - GWDG

Oscillations, Waves and Interactions, pp. 435–460
edited by T. Kurz, U. Parlitz, and U. Kaatze
Universitätsverlag Göttingen (2007) ISBN 978–3–938616–96–3
urn:nbn:de:gbv:7-verlag-1-16-3
DPI60plus – a future with biophysics
S. Lakämper and C. F. Schmidt
Drittes Physikalisches Institut, Georg-August-Universität Göttingen
Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
Abstract. In this review we first give a short introduction into the techniques currently in
use and development to establish biophysics as a field of research at the DPI. On this basis,
we then continue to sketch recent research highlights, covering the growing group’s entire
scientific range. Examples are presented to illustrate the intriguing physical complexity of
biological matter and the wealth of physical approaches to study it.
The research focus of the Drittes Physikalisches Institut is changing with a change
of guards in 2006. The central activities will be in the area of biophysics and physics of
complex systems. Biophysics is an interdisciplinary and rather broad field of research,
with strong ties to condensed matter physics, statistical physics and various kinds of
technical branches of physics. Here we want to highlight recent advances in a variety
of projects in the biophysics group. We want to show how approaches and techniques
from physics can help to understand very diverse systems from single molecules to
complex polymer-networks in soft condensed matter and artificial cell-systems, as
well as real cells and tissues. This overview is not intended to present a complete
review of the field, but rather to provide a snapshot of current activities.
Experimental research hinges on technologies, and to be on the cutting edge often
requires the development of new approaches that can open new fields of inquiry.
We use and further develop a variety of approaches, grouped around so called single
molecule techniques such as Atomic Force Microscopy (AFM), single-molecule
fluorescence microscopy, optical trapping techniques and combinations thereof. The
following sections give an introduction to these methods before we touch on current
research projects.
1 Introduction to technologies
1.1 Atomic force microscopy
AFM – developed in the 1980s by Binnig and Rohrer as well as Quate and Hansma
– initially as an expansion of Scanning Tunneling Microscopy (STM) – has evolved
into an important research tool, particularly in biophysics. AFM probes surfaces
by mechanical scanning with a nanometre-sized sharp tip mounted to a pliant cantilever.
The deflection of a laser beam reports the force exerted on the tip, which
is converted to a topographic image of the surface after 2D-scanning the object of