AVS 50th International Symposium
    Homeland Security Topical Conference Thursday Sessions
       Session HS-ThM

Paper HS-ThM7
Comparison of Bioassay Surface Chemistries on Gold and Alumina Films

Thursday, November 6, 2003, 10:20 am, Room 309

Session: Detection of Biological Agents and Self-Cleaning of Contaminated Surfaces
Presenter: S.P. Mulvaney, Naval Research Laboratory
Authors: S.P. Mulvaney, Naval Research Laboratory
C.L. Cole, Naval Research Laboratory
J.C. Rife, Naval Research Laboratory
K.A. Wahowski, Naval Research Laboratory
L.J. Whitman, Naval Research Laboratory
Correspondent: Click to Email
The surface bioaffinity coating is arguably the most critical component of any biosensor based on ligand-receptor capture on a solid substrate. The characteristics of this interface have profound effects on the overall performance of the sensor, affecting the assay sensitivity and selectivity (including background due to non-specific binding), and signal transduction. The physical properties of the sensor surface must be compatible with the detection method employed and chemically suitable for functionalizing with receptor biomolecules such as antibodies or oligonucleotides. The utility of gold films for electrochemical and optical detection schemes has made it one of the most commonly used sensor surfaces. One common approach to functionalizing gold is to first conjugate the desired biomolecules to a mercaptan functional group which can then immobilized on the surface via a Au-S bond. Alternatively, thiolated self-assembled monolayers (SAMs) can be used as a base for subsequent conjugation with biomolecules. SAM-based films, while effective, often lack the reproducibility required for reliable, quantitative assays. Therefore, we are exploring alternate surfaces and surface chemistries. We have developed and characterized multilayer, biocompatible polymer films on alumina surfaces and found them to be more reproducible than similar films on gold. The effects on assay performance for various chemistries on top of gold and alumina films will be compared and contrasted as used in the Bead Array Counter (BARC),@footnote 1@ a biosensor system that uses paramagnetic beads. CL Cole and KA Wahowski are employees of Nova Research, Inc., Alexandria, VA. @FootnoteText@ @footnote 1@Edelstein et. al., Biosens. Bioelectron. 2000, 14, 805-813.