AVS 47th International Symposium
    Biomaterial Interfaces Monday Sessions
       Session BI+SS-MoM

Paper BI+SS-MoM1
Suspended Lipid Bilayers on Porous Alumina Surfaces

Monday, October 2, 2000, 8:20 am, Room 202

Session: Biological Surface Science
Presenter: C. Steinem, WWU Muenster, Germany
Authors: C. Steinem, WWU Muenster, Germany
J. Drexler, WWU Muenster, Germany
C. Hennesthal, WWU Muenster, Germany
Correspondent: Click to Email
The study presents a new class of artificial membrane system "suspended bilayers" closing up the gap between solid supported membranes (SSMs) and black lipid membranes (BLMs). Suspended bilayers were prepared on the basis of porous alumina surfaces which were produced by an anodic etch of neat alumina foils. Gold was evaporated on the upper surface of the porous material. The porous material was characterized by scanning electron microscopy (SEM), scanning force microscopy (SFM) and impedance spectroscopy. As revealed by SEM and SFM pores exhibit a mean diameter of 65 nm. Functionalization of the upper gold surface was achieved by self assembly of 3-mercaptopropionic acid (MPA) rendering the surface negatively charged at pH 8.6. To obtain suspended solid supported we fused unilamellar vesicles of N,N-dimethyl-N,N-dioctadecyl ammonium bromide varying in their sizes on the MPA-covered surface. Bilayer patches spanning the pores were visualized by scanning force microscopy in buffer using contact mode. The bilayer covered nanopores are thought to serve as second aqueous compartments of femtoliter volume providing enough space to incorporate transmembrane proteins and to generate ion gradients across the membrane together with the ability to use sensitive surface analysis tools.