Berlin 2015 – scientific programme
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BP: Fachverband Biologische Physik
BP 35: Membranes and vesicles II (joint BP/CPP)
BP 35.5: Talk
Wednesday, March 18, 2015, 16:15–16:30, H 1028
Ultra-thin self-hydrated artificial membrane composed of DPPC and chitosan deposited without solvents — Maria J. Retamal1,2, Marcelo A. Cisternas1,2, Sebastian E. Gutierrez-Maldonado3, Tomas Perez-Acle3, Birger Seifert1,2, Mark Busch4, Patrick Huber4, and •Ulrich G. Volkmann1,2 — 1SurfLab UC, Instituto de Fisica, Pontificia Universidad Catolica de Chile (UC), Santiago, Chile — 2CIEN-UC, Santiago, Chile — 3DLab, Fundación Ciencia y Vida, Santiago, Chile — 4Institute of Materials Physics and Technology, Hamburg Univ. of Technology (TUHH), Hamburg-Harburg, Germany
We present the formation and characterization of a phospholipid bilayer (dipalmitoylphosphatidylcholine, DPPC) on a mattress of a polysaccharide (Chitosan) that keeps the membrane hydrated. The deposition of Chitosan (~25 Å) and DPPC (~60 Å) was performed from the gas phase in high vacuum onto a substrate of Si(100). The layer thickness was controlled in situ using Very High Resolution Ellipsometry (VHRE). Raman spectroscopy studies show that neither Chitosan nor DPPC molecules decompose during evaporation. With VHRE and AFM we have been able to detect phase transitions in the membrane. The presence of the Chitosan interlayer as a water reservoir is essential for both DPPC bilayer formation and stability. Our experiments at SurfLab UC show that the proposed sample preparation from the gas phase is reproducible and provides a natural environment for the DPPC bilayer. Reference: www.aip.org/publishing/journal-highlights/artificial-membranes-silicon