Orientation of antibodies on a 3-aminopropyltriethoxylsilane-modified silicon wafer surface

An antibody can be specifically oxidized with periodate (NaIO4) on the carb ohydrate side chains at its C-terminal. Rabbit anti-hepatitis B surface ant igen (anti-HBsAg) IgG antibodies were bound to the silicon wafer surface by covalent bonds between aldehydes generated on the carbohydrate side chains of the antibodies and the reactive amine groups of 3-aminopropyltriethoxyl silane(APTES)-modified silicon wafer surfaces. A control experiment was als o performed by direct attachment of antibodies to glutaraldehyde-treated si licon surfaces. Two different coupling antibody strategies were investigate d in this paper. Atomic force microscopy was used to observe the orientatio n of the site-directed and random attachment of rabbit anti-HBsAg IgG antib odies and the conservation of their antigen-binding capacity (AgBC) was ass essed using an enzyme immunoassay (EIA).