Patent ID: 8303910

Claim:
A biosensor determining whether an analyte is present or not in a liquid specimen, or measuring a concentration of the analyte in the liquid specimen, comprising: a substrate including a first end where the liquid specimen is applied and a second end opposite to the first end; a specimen application portion adjacent the first end of the substrate, allowing the liquid specimen to be applied therein, the specimen application portion including a space-forming member and an application space enclosed by the space-forming member, the space-forming member extending along the substrate and including a top wall and opposing side walls; a reaction reagent retained on a surface of the space-forming member that faces the application space in the specimen application portion; a development flow channel formed downstream of the specimen application portion, in which the liquid specimen having reacted with the reaction reagent is developed toward the second end of the substrate, the development flow channel being made of a material such that the liquid specimen and the reaction reagent in the specimen application portion is developed by a capillary force; a measurement region disposed in the development flow channel that measures whether the analyte is present or not in the liquid specimen, or measures the concentration of the analyte in the liquid specimen; and an auxiliary substrate disposed on the substrate that adjusts a thickness of the application space, wherein the application space extends along the substrate from a first opening defined at a first end of the specimen application portion to a second opening defined at a second end of the specimen application portion, the first opening is located adjacent the first end of the substrate, wherein the first opening is sized to allow the liquid specimen to be drawn into the biosensor by a capillary force, and wherein the space-forming member is made of a liquid impermeable material, the space-forming member cooperates with a liquid impermeable surface such that the application space between the first and second openings is enclosed entirely by liquid impermeable material, wherein the liquid impermeable material enclosing the application space helps avoid retention of the liquid specimen on an inner surface of the application space, thereby facilitating entry of the liquid specimen to the development flow channel.