Patent ID: 7944563

Claim:
A sensing apparatus, comprising: measuring light emission means for emitting measuring light of a predetermined polarized state; a waveguide member including a sensing surface which is modified by a surface modification substance so that only a specific target substance can be bound thereto, in which the measuring light entering therein under a condition of total internal reflection on said sensing surface is totally reflected to generate evanescent light on said sensing surface; detection means disposed at a side of said waveguide member or outside said waveguide member with respect to said sensing surface to detect an amount of scattered light of the evanescent light; and an analyzer disposed between said waveguide member and said detection means so as to face said sensing surface, wherein: said target substance is labeled by a fine metal particle selectively bound to said target substance; said measuring light emission means, said waveguide member, and said analyzer are included in an optical waveguide system which sets a polarized state of scattered light from said sensing surface generated when said target substance labeled by said fine metal particle is absent on said sensing surface in a crossed nicol relation to said analyzer; and the amount of the evanescent light scattered by said fine metal particle labeling said target substance bound to said surface modification substance modifying said sensing surface is detected by said detection means.