Method for detecting analyte concentration

A method for detecting an analyte concentration, comprising:

• providing at least two reaction solutions, wherein each of the reaction solutions comprises a first complex, and the first complex comprises:
• a labeling particle;
• a binding ligand, fixed on a surface of the labeling particle;
• and
• a substrate, binding to the binding ligand;
• simultaneously adding an analyte standard and metal nanoparticles into one of the reaction solutions, so as to form a second complex, wherein the binding ligand is modified onto each of the metal nanoparticles, the substrate of the first complex binds to the binding ligand of the metal nanoparticles for forming the second complex, and the analyte standard in the one of the reaction solutions has a known concentration;
• simultaneously adding a sample including an analyte sample and the metal nanoparticles into the other one of the reaction solutions, so that the substrate of the first complex binds the binding ligand of the metal nanoparticles to form a third complex, wherein the analyte sample in the other reaction solution has an unknown concentration, an equivalent particle size of the labeling particle is greater than an equivalent particle size of each of the metal nanoparticles, and the substrate, the analyte standard and the analyte sample are substantially the same substance;
• and
• detecting a first heat diffusivity of the second complex and a second heat diffusivity of the third complex using a light source;
• and
• performing an analyte concentration determination step, wherein when the first heat diffusivity is less than the second heat diffusivity, the unknown concentration is higher than the known concentration;
• or, when the first heat diffusivity is greater than the second heat diffusivity, the unknown concentration is lower than the known concentration.