Surface plasmon enhanced fluorescence measurement device and surface plasmon enhanced fluorescence measurement method
The present invention pertains to a surface plasmon enhanced fluorescence analysis device and a surface plasmon enhanced fluorescence measurement method which use GC-SPFS and make it possible to detect a substance to be detected with high sensitivity. This surface plasmon enhanced fluorescence measurement device has: a light source for irradiating the diffraction grating of a chip with excited light; a polarizer for removing linearly polarized light from fluorescent light emitted from a fluorescent substance on the diffraction grating; and a photodetector for detecting the linearly polarized light removed by the polarizer.
1. A surface plasmon enhanced fluorescence measurement device, comprising:
a chip including a metal film on which a diffraction grating is formed and a capturing body immobilized on the diffraction grating, wherein a detection object substance labeled with a fluorescence material is couplable with the capturing body,
a light source irradiating the diffraction grating with excitation light to excite the fluorescence material with an enhanced electric field such that the fluorescence material emits fluorescence;
a polarizer extracting linear polarization light from the fluorescence emitted from the fluorescence material; and
a light detector detecting the linear polarization light extracted by the polarizer, whereby a presence or an amount of the detection object substance is detectable by the surface plasmon enhanced fluorescence measurement device by irradiating the diffraction grating with the excitation light.
2. The surface plasmon enhanced fluorescence measurement device according to claim 1 further comprising a processing section processor processing a detection value of the light detection section detector, wherein:
the polarizer simultaneously or separately extracts, from the fluorescence emitted from the fluorescence material, first light in which an angle of a direction of electric field oscillation with respect to a plane including a normal to a surface of the metal film and an optical axis of the excitation light is 0±30° and second light in which an angle of a direction of electric field oscillation with respect to the plane is 90±30°;
the light detection section detector detects each of the first light and the second light; and
the processing section processor calculates a difference value between a detection value of the first light and a detection value of the second light.
3. The surface plasmon enhanced fluorescence measurement device according to claim 2 , wherein:
the first light is p-polarization light with respect to the surface of the metal film; and
the second light is s-polarization light with respect to the surface of the metal film.
4. The surface plasmon enhanced fluorescence measurement device according to claim 1 , wherein the excitation light is applied to the metal film at a predetermined incident angle θ 1 and the fluorescence is emitted at an emission angle θ 2 that is different from the incident angle, the incident angle θ 1 and the emission angle θ 2 are each relative to a line normal to the metal film.
5. The surface plasmon enhanced fluorescence measurement device according to claim 1 , wherein the excitation light is applied to the metal film at a predetermined incident angle θ 1 at which an intensity of the enhanced electric field formed by surface plasmon resonance is maximized.