Robust, Functional, and Flexible Thin-Films
Attachment of thin-films to our sensor platforms: Our team has developed a novel thin-film that allows specific attachment of ligands to a surface while preventing non-specific binding. To this end, aminopropyldiethoxymethyl silane was attached to a silica surface through a vapor deposition process. This vapor deposition process is at the heart of our SAM chemistry, as it is rapid, inexpensive, and simple. The aminosilane is modified with commercially available polyethylene glycol (PEG) reagents to create the binding surfaces. These surfaces present a small percentage of a functional group, which is available for binding, and a large percentage of molecules that are highly inert to chemical reaction or biological interaction. The films are characterized by fluorescence microscopy, atomic force microscopy, water contact angle, and ellipsometry.
Stability of the thin-films was assessed by long-term storage. Contact angle did not change significantly after storing the films for a year in ambient air. Functionally, the thin-films were validated using sandwich immunoassays against a variety of targets. Most of the data surrounds detection of Bacillus anthracis protective antigen (PA), but these films have been used in the detection of tuberculosis antigens (LAM and Antigen-85), carcinoembryonic antigen, and human influenza, as well as for multi-analyte detection of PA, B. anthracis lethal factor, and streptavidin in the same assay using different colored quantum dots.