Surface Plasmon Resonance/Surface Plasmon Enhanced Fluorescence: An Optical Technique for the Detection of Multicomponent Macromolecular Adsorption at the Solid/Liquid Interface

Abstract

We describe an optical technique for the measurement of macromolecular adsorption at the solid/liquid interface when multiple species are present. The technique combines surface plasmon resonance (SPR) with simultaneous surface plasmon enhanced fluorescence (SPEF). The relative ease of construction and linear correlation between SPR and SPEF signals make the technique amenable for coadsorption studies or multiple ligand binding experiments. Here, we demonstrate the utility of the technique with a biotin/avidin/BSA “sandwich” experiment. We then apply SPR/SPEF for the simultaneous monitoring of enzyme adsorption and substrate cleavage of a protease interacting with a substrate surface.