Real-Time Binding Kinetics Monitored with Surface Plasmon Resonance Imaging in a Diffusion-Free Environment

Surface Plasmon Resonance Imaging (SPRI) is an optical technique emerged as a powerful tool for the simultaneous monitoring of interactions of biomolecules arrayed onto gold substrates. To take fully advantage of the SPRI approach a precise control of the fluidic of the analyte solution is imposed. The diffusion between the flowing buffer and the analyte solution which is established within the fluidic system creates a liquid volume where a gradient in the analyte concentration is present. Such gradient is shown to affect the kinetics parameters obtained from the SPRI response. We present results obtained from a new delivery approach based on the use of air bubbles. The advantages offered by the new approach are demonstrated by using two different interacting biomolecular systems: the streptavidin-biotin system and the Ricinus Communis Agglutinin lectin-asialofetuin.