Target substance detecting element, target substance detecting apparatus, and target substance detecting method

A target substance detecting apparatus using localized surface plasmon resonance, which detects kinds of target substances which have the same recognition site recognized by a specific capturing body but whose kinds are different mutually, comprising a target substance detecting element, a reaction mechanism for contacting a sample containing a target substance with the target substance detecting element, a light source for irradiating the target substance detecting element with light, a detecting unit for detecting a detection signal from the target substance detecting element, and an analyzing unit for analyzing the detection signal to determine the target substance,

• the target substance detecting element comprising a base material, two or more kinds of metal structures which are mutually different in shape, material or size and which give rise to localized surface plasmon resonance by receiving the light, provided on a surface of the base material, and a target capturing unit provided on each surface of the metal structures;
• the detecting unit acquiring a spectrum of outgoing light from the target substance detecting element contacted with the sample, classifying the acquired spectrum according to kind of the metal structures to determine spectral peaks, and detecting a change of the spectral peak of each kind of the metal structures from the state before the contact with the sample to the state after the contact as the detection signal;
• and
• the analyzing unit integrating and analyzing the detected detection signals to calculate the concentration of each kind of the target substances.