SURFACE-PLASMON RESONANCE STUDIES OF CHEMISORBED BIOTIN STREPTAVIDIN MULTILAYERS

Surface plasmon resonance spectroscopy has been used to confirm that a monolayer of biotin may be immobilized by chemisorption onto evaporated gold films and subsequently used to bind a monolayer of streptavidin. As expected, the strong affinity of the protein for the biotin ligand ensures that the binding of the protein layer is highly specific. No non-specific binding occurs to the biotinylated gold surface; the protein layer is resistant to washing in 1 M NaCl. It is suggested that multilayer structures may be assembled by chemisorption of successive protein monolayers using a bifunctional bisbiotin ligand for connecting individual layers.