AVS 52nd International Symposium
    Biomaterial Interfaces Tuesday Sessions
       Session BI1-TuA

Paper BI1-TuA3
Toward Improved Biosensors: Studies of Protein Immobilization on Polymerized Planar Supported Lipid Bilayers

Tuesday, November 1, 2005, 2:40 pm, Room 311

Session: Sensors/Diagnostics
Presenter: J. Joubert, University of Arizona
Authors: J. Joubert, University of Arizona
E.H. Elandaloussi, University of Arizona
S.S. Saavedra, University of Arizona
Correspondent: Click to Email
Planar supported phospholipid bilayers maintain high resistance to nonspecific protein adsorption, which is a useful attribute for biosensor surfaces. However, their instability to drying is a factor reducing their commercial implementation. By crosslinking polymerizable lipid monomers (e.g., bis-sorbylphosphatidylcholine, bis-SorbPC) bilayer stability can be increased while maintaining biofouling (i.e., nonspecific protein adsorption) resistance. Further, the properties of this poly(bis-SorbPC) platform can be modified to study nonspecific and specific interactions with proteins for biosensing applications. One modification for studying nonspecific interactions involves adding various percentages and types of nonpolymerizable lipid to the bilayer before polymerization and drying to introduce a varying number and size of defect sites with differing polarities (hydrophobic for exposed lower lipid leaflet and hydrophilic for exposed glass) in a controlled manner. Studies of nonspecific protein binding to this variety of defects in these bilayers can aid in understanding fouling and subsequent failure of biosensors. Another set of modifications for analyzing specific protein interactions is aimed at immobilizing analyte-specific receptor proteins onto the bilayer and analyzing the degree to which sensing activity is retained. These modifications include doping into the bilayer a polymerizable lipid with a reactive (e.g., primary amine) headgroup for protein receptor attachment or microcontact printing the protein receptor onto the polymerized bilayer. This talk will discuss development of such methodologies to attach proteins to poly(lipid) bilayers to study protein-lipid and protein-protein interactions on such surfaces.