METHOD AND APPARATUS FOR DETECTING LOW- CONCENTRATION BIOCHEMICAL COMPONENT EXISTING IN TEST MEDIUM USING SURFACE PLASMON RESONANCE

摘要

PURPOSE: To determine the concentration of one or more than one kind of component in a sample medium simultaneously by difference measurement by applying a metal layer with an adjustable selector having effect on the incident angle position of a resonance curve. CONSTITUTION: A polarized light beam impinges on an incident surface through a prism 2 and repeats total reflection and then the attenuated intensity of outgoing light beam is measured. Incident angle position of a resonance curve is then determined under the influence of variation in the dielectric constant of a test medium 3 near a metal layer 1 caused by the components thereof. More specifically, the metal layer 1 is applied with an adjustable selector having effect on the incident angle position of resonance curve. Since selective coupling can be made and the concentration of one component can be set higher than that of other component, concentration of one or more than one kind of component in the medium 3 can be determined simultaneously by difference measurement.