Method of detecting target substance and detection reagent for target substance

Abstract

To provide a method of detecting a target substance in which silica particles are used, and a sensitizing factor is increased without any reduction in measurement accuracy, provided is a method of detecting a target substance including: a first step of mixing a specimen liquid containing at least the target substance and a particle dispersion, which comprises first particles each having a site that specifically binds to the target substance, to produce a liquid sample; and a second step of performing the optical measurement of the liquid sample, wherein the liquid sample comprises second particles, wherein the ratio of the average particle diameter of the second particles to the average particle diameter of the first particles in the liquid sample is 0.03 or more and 0.24 or less, and wherein the refractive index of the second particles is smaller than the refractive index of the first particles.

Dependencies are inferred from the claim text.