AVS 46th International Symposium
    Biomaterial Interfaces Group Monday Sessions
       Session BI-MoA

Paper BI-MoA2
Light Activated Affinity Micropatterning of Proteins

Monday, October 25, 1999, 2:20 pm, Room 613/614

Session: Protein Solid-Surface Interactions I
Presenter: A. Chilkoti, Duke University
Authors: A. Chilkoti, Duke University
Z.-P. Yang, Duke University
W. Frey, Duke University
T. Oliver, Food and Drug Administration
Correspondent: Click to Email
Biomolecular patterning has diverse applications, which range from modulation of cell-substrate interactions in biomaterials and tissue engineering, to the fabrication of multianalyte biosensors, clinical assays, and genomic arrays. Motivated by these applications, we have developed a method to micropattern proteins on well-defined gold substrates, which we term light-activated affinity micropatterning of proteins (LAMP). LAMP is a multi-step patterning process: first, a gold substrate is functionalized with a binary mixture of 11-mercaptoundecanol and 16-mercaptohexadecanoic acid to provide a non-fouling, reactive self-assembled monolayer (SAM) template on gold. Next, the carboxylic acid end groups in the binary SAM are coupled to methyl @alpha@-nitropiperonyloxycarbonyl biotin succinimidyl ester (caged biotin ester) through a diamine linker. Deprotection of caged biotin by spatially-defined uv illumination at 350-360 nm reconstitutes biotin in the illuminated region, and subsequent incubation with streptavidin results in selective binding of streptavidin to regions that were previously deprotected. We have investigated and optimized LAMP by contact angle goniometry, ellipsometry, surface plasmon resonance, and X-ray photoelectron spectroscopy to maximize ligand density and pattern contrast. Micropatterning of streptavidin and an anti-biotin monoclonal antibody has been demonstrated with a spatial resolution of ~5 microns by imaging ellipsometry and confocal light microscopy of fluorophore-derivatized proteins. LAMP can be further extended to allow spatially-resolved micropatterning of multiple biomolecules by repeated cycles of spatially-defined deprotection, streptavidin incubation, followed by binding of the biotinylated moiety of interest.