Patent ID: 8039267
Filing Date: 2011-10-18
Classification: G01N,Y10S

Abstract:
1. A detection method comprising the steps of: preparing a sensor chip including a dielectric plate and a sensor portion that has at least a metal layer deposited on a surface of the dielectric plate; binding a fluorescent-label binding substance in an amount corresponding to the amount of a detection target substance contained in a liquid sample to the sensor portion by contacting the liquid sample with the sensor portion; irradiating the sensor portion with excitation light to generate an enhanced optical field on the sensor portion; and detecting the amount of the detection target substance based on the amount of light generated by excitation of a fluorescent label contained in the fluorescent-label binding substance, the fluorescent label being excited in the enhanced optical field, wherein a fluorescent substance the charge state of which changes in the liquid sample according to the pH of the liquid sample is used as the fluorescent label, the fluorescent substance containing a plurality of fluorescent dye molecules enclosed by a material that transmits fluorescence output from the plurality of fluorescent dye molecules, and wherein in the state in which the fluorescent-label binding substance has bound to the sensor portion, the fluorescent substance is attracted to a surface of the sensor portion by adjusting the pH of the liquid sample in such a manner to neutralize the charge state of the fluorescent substance, and wherein the amount of the detection target substance is detected in the state in which the fluorescent substance is attracted to the surface of the sensor portion wherein plasmons are excited in the metal layer by irradiation with the excitation light to generate the optical field enhanced by the plasmons, and the amount of detection target substance is detected by detecting, as the light generated by the excitation of the fluorescent label, fluorescence output from the fluorescent label by the excitation of the fluorescent label.