| 摘要 |
PURPOSE: To provide the information on the presence or concentration of an element in a sample by making it possible to reversely bond sensitive substance molecules by light which does the total internal reflection in the interface between a slide and a metal layer, reaches a lens and strikes a photodetector from there. CONSTITUTION: A metal layer 3 is provided over the surface of a slide 2 in the farther side from a prism 1. Next to this, a light beam 4 from a light source 5, e.g. a laser converges on one point on the boundary plane between the slide 2 and the metal layer 3 by a lens 6. Next to this, the light 4 does the total internal reflection in the interface between the slide 2 and the metal lawyer 3, diverged and reaches a lens 7, and from there a parallel light beam strikes a photodetector 8. In the case when the conditions are correct and the range of the incidence angle of the light 4 is appropriate, surface plasmon resonance occurs at the reflection point, the characteristics of the resonance sensitively depends on the refractive index of a medium on the surface of the metal layer 3 in the opposite side of the slide 2. In the case when an antigen is present in a sample, bonding and the changes in refractive index at a spot 9 occur and the changes in refractive index can be measured by a detector 8. |
