Biosensor, thin film electrode forming method, quantification apparatus, and quantification method

Abstract

A biosensor is disclosed comprising a support; a conductive layer composed of an electrical conductive material such as a noble metal, for example gold or palladium, and carbon; slits parallel to and perpendicular to the side of the support; working, counter, and detecting electrodes; a spacer which covers the working, counter, and detecting electrodes on the support; a rectangular cutout in the spacer forming a specimen supply path; an inlet to the specimen supply path; a reagent layer formed by applying a reagent containing an enzyme to the working, counter, and detecting electrodes, which are exposed through the cutout in the spacer; and a cover over the spacer. The biosensor can be formed by a simple method, and provides a uniform reagent layer on the electrodes regardless of the reagent composition.

1 - 44 . (canceled) 
     
     
         45 . A method of manufacturing a biosensor for quantifying a substrate in a sample liquid, the method comprising the steps of:
 providing an insulating support;   providing an electrically conductive layer on a surface of the insulating support;   forming an electrode pattern and an identification pattern on the insulating support from the electrically conductive layer by using a laser, the electrode pattern defining at least a working electrode and a counter electrode;   providing a reagent layer covering a portion of the electrode pattern;   providing a spacer layer covering a portion of the reagent layer, the spacer layer defining a supply path for bringing the sample liquid into contact with the reagent layer; and   providing a cover on the spacer layer;   
       wherein:
 a portion of the reagent layer is in the supply path, and the supply path is narrower than the reagent layer; 
 a portion of the counter electrode and a portion of the working electrode are in the supply path; and 
 no portion of the identification pattern is in the supply path. 
 
     
     
         46 . The method according to  claim 45 , wherein the electrically conductive layer is formed by vapor deposition or by sputtering evaporation. 
     
     
         47 . The method according to  claim 45 , wherein a masking plate having a pattern corresponding to the electrode pattern is used to mask the electrically conductive layer when the laser is used to form the electrode pattern. 
     
     
         48 . The method according to  claim 45 , wherein a masking plate having a pattern corresponding to the identification pattern is used to mask the electrically conductive layer when the laser is used to form the identification pattern. 
     
     
         49 . The method according to  claim 45 , further comprising the step of roughening the surface of the insulating support before providing the electrically conductive layer thereon. 
     
     
         50 . The method according to  claim 49 , wherein the surface of the insulating support is roughened by being exposed to an excited gas in a vacuum chamber. 
     
     
         51 . The method according to  claim 50 , wherein the step of roughening the surface of the insulating support and the step of providing the electrically conductive layer thereon are performed in the same vacuum chamber. 
     
     
         52 . The method according to  claim 45 , wherein the identification pattern consists of one part. 
     
     
         53 . The method according to  claim 45 , wherein the identification pattern consists of two parts. 
     
     
         54 . The method according to  claim 45 , wherein the identification pattern consists of three parts. 
     
     
         55 . The method according to  claim 45 , wherein the identification pattern consists of more than three parts. 
     
     
         56 . The method according to  claim 45 , wherein the insulating support comprises a resin material. 
     
     
         57 . The method according to  claim 45 , wherein the electrically conductive layer comprises a noble metal selected from the group consisting of palladium, platinum, gold, and ruthenium. 
     
     
         58 . The method according to  claim 45 , wherein the electrically conductive layer comprises gold. 
     
     
         59 . The method according to  claim 45 , wherein the electrode pattern has a thickness from 3 nm to 100 nm. 
     
     
         60 . The method according to  claim 45 , wherein the identification pattern has a thickness from 3 nm to 100 nm. 
     
     
         61 . The method according to  claim 45 , wherein the electrode pattern has a thickness from 3 nm to 50 nm. 
     
     
         62 . The method according to  claim 45 , wherein the identification pattern has a thickness from 3 nm to 50 nm. 
     
     
         63 . The method according to  claim 45 , wherein the electrode pattern has a wettability index equal to or greater than 48 dyn/cm. 
     
     
         64 . The method according to  claim 45 , wherein the identification pattern has a wettability index equal to or greater than 48 dyn/cm. 
     
     
         65 . The method according to  claim 45 , wherein the reagent layer comprises an enzyme. 
     
     
         66 . The method according to  claim 65 , wherein the reagent layer further comprises an electron transfer agent. 
     
     
         67 . The method according to  claim 66 , wherein the reagent layer further comprises a hydrophilic polymer. 
     
     
         68 . The method according to  claim 45 , wherein the biosensor comprises an air hole that leads to the supply path. 
     
     
         69 . The method according to  claim 68 , wherein the supply path is sufficiently narrow to draw in the sample liquid by capillary action. 
     
     
         70 . The method according to  claim 45 , wherein the portion of the counter electrode in the supply path is equal to or larger than the portion of the working electrode in the supply path. 
     
     
         71 . The method according to  claim 45 , wherein a portion of the counter electrode in the supply path is closer than any portion of the working electrode in the supply path to an inlet of the supply path. 
     
     
         72 . The method according to  claim 45 , wherein the working electrode and the counter electrode are separated by 0.005 mm to 0.3 mm in the supply path. 
     
     
         73 . The method according to  claim 45 , wherein the electrode pattern further defines a detecting electrode, and a portion of the detecting electrode is in the supply path. 
     
     
         74 . The method according to  claim 73 , wherein a portion of the counter electrode in the supply path is closer than any portion of the working electrode in the supply path to an inlet of the supply path, and the entire portion of the working electrode in the supply path is closer than any portion of the detecting electrode in the supply path to the inlet of the supply path. 
     
     
         75 . The method according to  claim 73 , wherein the detecting electrode is separated from the closest of the working electrode and the counter electrode by 0.005 mm to 0.3 mm in the supply path.