Formation of Pit-Spanning Phospholipid Bilayers on Nanostructured Silicon Dioxide Surfaces for Studying Biological Membrane Events

Zwitterionic phospholipid vesicles are known to adsorb and ultimately rupture on flat silicon dioxide (SiO₂ ) surfaces to form supported lipid bilayers. Surface topography, however, alters the kinetics and mechanistic details of vesicles adsorption, which under certain conditions may be exploited to form a suspended bilayer. Here we describe the use of nanostructured SiO₂ surfaces prepared by the colloidal lithography technique to scrutinize the formation of suspended 1-palmitoyl-2-oleoyl-sn -glycero-3-phosphocholine (POPC) lipid bilayers from a solution of small unilamellar lipid vesicles (SUV_s ). Atomic force microscopy (AFM) and quartz crystal microbalance with dissipation monitoring (QCM-D) were employed to characterize nanostructure fabrication and lipid bilayer assembly on the surface.