Patent ID: 7863059

Claim:
A target substance detection method for detecting a target substance in a specimen, comprising the steps of: contacting with a specimen a target substance detecting element, including at least a base, a metal structure which exists on a surface of the base and a first capturing body for capturing a target substance which exists on a surface of the metal structure; after the contacting step or simultaneously with the contacting step, contacting with the target substance detecting element a labeling material comprised of a labeling substance and a second capturing body for capturing a target substance; and acquiring an absorption spectrum (A) of the target substance detecting element contacted with the specimen and the labeling material, wherein the employed labeling substance is a substance that a slope of a tangent of an absorption spectrum (C) of the labeling substance in a liquid at a peak wavelength (Î» z ) of an absorption spectrum (B) of the target substance detecting element, being contacted with the specimen and the second capturing body, in the liquid is larger than zero.