Patent ID: 7898659

Claim:
A sensor used in sensing, the sensor comprising: a sensing surface, to which a specific substance to be detected can bind, wherein sensing is performed by marking the substance to be detected with a fluorescent marker that selectively binds to the substance to be detected and by detecting one of two-photon excitation fluorescence and multi-photon excitation fluorescence of the fluorescent marker, the sensor further comprising: a metal portion, at least a portion of which is exposed at the sensing surface, and in which localized plasmons can be excited, wherein the sensing surface is illuminated with measurement light having a wavelength that can excite localized plasmons in the metal portion and that is an absorption wavelength of the fluorescent marker, at which the fluorescent marker emits one of the two-photon excitation fluorescence and the multi-photon excitation fluorescence; and wherein a substrate of the metal portion is made of a dielectric that has a plurality of minute pores formed therein, and wherein the plurality of minute pores have openings at least at the sensing-surface-side surface of the dielectric, and wherein the metal portion is formed by a plurality of metal elements, each including a filled portion formed by filling a minute pore in the dielectric and a projection portion formed on the filled portion in such a manner that the projection portion projects from the surface of the dielectric, and wherein the diameter of the projection portion is greater than that of the filled portion.