DFG Priority Program SPP 1164
Nano- & Microfluidics:
Bridging the Gap between
Molecular Motion and Continuum Flow
Nano- and microfluidics using optical tweezers with fast single particle tracking
| Project Leader: | Prof. Dr. Friedrich Kremer Universität Leipzig Fakultät für Physik und Geowissenschaften Leipzig |
Summary
In the previous application period an optical tweezers set-up was
developed which is especially suited for micro-rheological
measurements. It consists of custom-mad flow-cells, long-range
objective lenses and in particular an image analysis software ,which
enables one to exclude artefacts caused by interference effects. In
detail the following topics were studied: (i) forces of interaction
within one pair of blank colloids in media of varying ionic strength.
(ii) the flow resistance of single DNA-grafted colloids in ionic
solutions of different type and concentration, (iii) the interaction
between colloids grafted with DNA of varying length and (iv) the flow
resistance of one blank colloid in a polymer solution. The
results are discussed and analyzed in close collaboration with
theoreticians in the priority program.
Publications
- Gutsche, C., M. Salomo, Y.W. Kim, R.R. Netz and F. Kremer:
"The flow resistance of single DNA-grafted colloids as measured by Optical Tweezers"
J. Microfluidics and Nanofluidics, ISSN:1613-4982 (Paper) 1613-4990 (2006) - Kegler, K., M. Salomo, F. Kremer:
"Forces of interaction between DNA-grafted colloids: an Optical Tweezer measurement"
Physical Review Letters 98 (2007) 058304 - Gutsche, C., U.F.Keyser, K. Kegler, F. Kremer, P. Linse:
"Forces between single pairs of charged colloids in aqueous salt solutions"
in press (2007)