Dresden 2026 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 14: Poster Session II
BP 14.25: Poster
Dienstag, 10. März 2026, 18:00–21:00, P2
Local dynamical properties of lipid bilayers using Scanning Ion Conductance Microscopy (SICM) — •Eric Lieberwirth1, Franziska Dorn1, Regina Lange1, Una Janke2, Mihaela Delcea2, Ingo Barke1, and Sylvia Speller1 — 1Physics of Surfaces and Interfaces, Institute of Physics & LLM, University of Rostock, Germany — 2Biophysical Chemistry, Institute of Biochemistry, University of Greifswald, Germany
To determine dynamical properties of lipid bilayers, various experimental methods have been established, e. g. contour analysis and fluctuation spectroscopy. Based on Helfrichs theory from 1973 [1], bending rigidity and membrane tension of lipid bilayers can be derived. We demonstrate a local measurement approach by Scanning Ion Conductance Microscopy (SICM) on Giant Unilamellar Vesicles (GUVs) for evaluation of dynamic lipid bilayer properties. Using a nanopipette controlled via a feedback loop to maintain constant membrane-tip distance, we record time traces of local membrane height fluctuations with nanometer precision. In a contour analysis like approach [2], we obtain a bending rigidity of a few kBT and membrane tension of a few µ N m−1. Computation of the power spectral density (PSD) based on [3] combined with a global-local fit provides a second evaluation route with same data set, yielding in similar results. Differences and limitations of both methods are discussed.
[1] W. Helfrich, Zeits. für Naturfor. 28c (1973), p. 693-703
[2] J. F. Faucon et al., J. Phys. France 50 (1989), p. 2389-2414
[3] T. Betz & C. Sykes, Soft Matter 8 (2012), p. 5317-5326
Keywords: SICM; GUV; fluctuation spectroscopy; bending rigidity; membrane tension