AVS 47th International Symposium
    Biomaterial Interfaces Thursday Sessions
       Session BI+NS-ThA

Paper BI+NS-ThA10
Formation and Patterning of Supported Fluid Lipid Bilayers on a High Refractive Index Substrate

Thursday, October 5, 2000, 5:00 pm, Room 202

Session: Biosensors
Presenter: C.M. Ajo, Stanford University
Authors: C.M. Ajo, Stanford University
L.C. Kam, Stanford University
S.G. Boxer, Stanford University
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Supported lipid bilayers are a useful model system to probe cellular membrane components and their interactions in a near native environment. Specifically, membrane components reconstituted in supported lipid bilayers create a well-defined two-dimensional system that can be manipulated - and then interrogated with a variety of surface specific and optical techniques. Several of these techniques rely on evanescent fields to probe the region near the solid support-lipid bilayer interface. However, the solid support typically has been a low refractive index material that permits the evanescent wave to penetrate significantly beyond the bilayer (650 Å). Here we report the formation of supported lipid bilayers on lithium niobate (LiNbO@sub 3@), a material with a high refractive index (n=2.3). Vesicle fusion onto lithium niobate forms a single uniform supported lipid bilayer that exhibits lateral diffusion properties similar to glass-supported lipid bilayers. By blotting and stamping,@footnote 1@ supported bilayers can be patterned reversibly, and the lipid components reorganize in response to an electric field. The high refractive index of lithium niobate restricts the penetration of an evanescent field to within 160 Å of the solid support-lipid bilayer interface. This provides a method to study the cell-supported lipid bilayer interface, since the relevant distances are on this order. Additionally, the transparency of lithium niobate ove a wide range of wavelengths makes it a useful substrate for both visible and infrared studies. @FootnoteText@ @footnote 1@J. S. Hovis and S. G. Boxer, Langmuir 16, 894 (2000).