Evaluating biofilm performance using surface plasmon resonance

Surface plasmon resonance (SPR) has been used as a diagnostic tool for over thirty years. Current technology is capable of the label-free characterization of both chemical and biological systems, however commercially available SPR systems have limited sensitivity and are difficult to use. A low cost biosensor with increased sensitivity is desired. A Metricon Prism Coupler was modified to function as an SPR spectrophotometer and a flow cell was designed for characterizing the binding of biotinylated beta-galactosidase to streptavidin. Instrumentation capability was determined using 633nm and 1550nm wavelength lasers to detect streptavidin-biotin chemistry on a biosensor. Streptavidin was bound to a self assembled monolayer of thiol groups and exposed to a dilute beta-galactosidase solution to assess the limit of detection. The flow cell design and injection system used to observe protein binding were validated and the instrumentation demonstrated an increased sensitivity at longer wavelengths.