Patent ID: 7652768

Claim:
A chemical sensing apparatus for detecting a target substance by immobilizing the target substance combined with a marker substance through a bond with a capturing substance, comprising: a light source; a metal thin film having an aperture smaller than a wavelength of a light emitted from the light source, or a metal fine particle smaller than the wavelength; a substrate bearing the metal thin film or the metal fine particle on the surface of the substrate; the capturing substance, bonded to a surface of the metal thin film or to a surface of the metal fine particle; and a photodetector for detecting light emitted from the light source through the aperture or scattered light emitted from the metal fine particle when irradiating the metal thin film or the metal fine particle with the light emitted from the light source, wherein the marker substance has a size from 1/10 times to 10 times that of the aperture or that of the metal fine particle.