| abstract |
(57) [Abstract] [Objective] To selectively excite only a fluorescently labeled antibody using surface plasmon resonance and measure the antigen concentration with high sensitivity. A triangular glass prism having a metal thin film on which an antibody is immobilized is mounted on a rotary table, and a sample solution containing an antigen is injected into a flow cell to form a metal thin film. Side to allow the antigen to bind to the antibody. Furthermore, a fluorescent labeling reagent containing a fluorescently labeled antibody is supplied, and the fluorescently labeled antibody is bound to the antibody bound to the antigen. Next, light normally absorbed by the fluorescently labeled antibody and light having a wavelength that is an integral multiple of that of the light are simultaneously incident from the prism side of the triangular glass prism 10 to excite the fluorescently labeled antibody by two-photon excitation or multiphoton excitation, The fluorescence generated when the light is incident on the prism side of the triangular glass prism at an incident angle at which the reflectance becomes the smallest is analyzed in spectrum. |