BIOANALYSIS WITH SURFACE-PLASMON RESONANCE

Research and development work has made surface plasmon resonance (SPR) into an accurate, sensitive and fast method with several bioanalytical applications. The first commercial instrument has also recently been introduced on the market. The present contribution reviews the use of SPR for biospecific interaction analysis and describes a recently developed SPR instrument. Special attention is paid to the use of a dextran layer on the surface of the thin metal film (gold) used for SPR. It is shown that with such a matrix on the surface, the evanescent electric field outside the metal surface is used more efficiently, which improves the analytical performance of the method. Furthermore, the matrix provides a convenient way of covalently binding biomolecules to the sensing surface, thus providing its necessary biospecificity. The chemistry of the coupling matrix is described as well as the optical and liquid-handling systems used. Finally, a few applications of the SPR instrument are demonstrated.