Biosensor

Abstract

In a biosensor for measuring a specific substance in a liquid sample, one or a combination of sugar alcohol, metallic salt, organic acid or organic acid salt which has at least one carboxyl group in a molecule, and organic acid or organic acid salt which has at least one carboxyl group and one amino group in a molecule, is included in a reagent layer provided on electrodes, thereby providing a highly-accurate biosensor which is excellent in stability and has high response (sensitivity, linearity) of the sensor to the substrate concentration.

1 . A biosensor for measuring the concentration of a specific substance in a sample solution, wherein
 sugar alcohol is included in a previously-provided reagent layer so that it is dissolved in the sample solution and specifically reacts to the specific substance in the sample solution.   
     
     
         2 . The biosensor as defined in  claim 1 , wherein
 the concentration of the specific substance is measured employing electrodes comprising at least a working electrode and a counter electrode provided on an insulating support.   
     
     
         3 . The biosensor as defined in  claim 2 , wherein
 the reagent layer is formed on the electrodes or so that the electrodes are arranged in a diffusion area where a reagent in the reagent layer is dissolved and diffused in the sample solution, and the reagent layer includes at least an enzyme and an electron transfer agent.   
     
     
         4 . The biosensor as defined in  claim 1 , wherein
 the sugar alcohol is chain polyhydric alcohol or cyclic sugar alcohol, or a substitution product or derivative of the sugar alcohol.   
     
     
         5 . The biosensor as defined in  claim 1 , wherein
 the sugar alcohol is either or both of multiol and lactitol.   
     
     
         6 . A biosensor for measuring the concentration of a specific substance in a sample solution, wherein
 metallic salt is included in a previously-provided reagent layer so that it is dissolved in the sample solution and specifically reacts to the specific substance in the sample solution.   
     
     
         7 . The biosensor as defined in  claim 6 , wherein
 the concentration of the specific substance is measured employing electrodes comprising at least a working electrode and a counter electrode provided on an insulating support.   
     
     
         8 . The biosensor as defined in  claim 7 , wherein
 the reagent layer is formed on the electrodes or so that the electrodes are arranged in a diffusion area where a reagent in the reagent layer is dissolved and diffused in the sample solution, and the reagent layer includes at least an enzyme and an electron transfer agent.   
     
     
         9 . The biosensor as defined in  claim 6 , wherein
 the metallic salt is metallic salt sulfate, metallic salt hydrogensulfate, metallic salt sulfite, metallic salt hydrogensulfite, or metallic salt hyposulfite.   
     
     
         10 . The biosensor as defined in  claim 6 , wherein
 the metallic salt is either or both of magnesium sulfate and calcium sulfate.   
     
     
         11 . The biosensor as defined in  claim 6 , wherein
 the metallic salt is metallic salt nitrate, metallic salt hydrogennitrate, metallic salt nitrite, metallic salt hydrogennitrite, or metallic salt hyponitrite.   
     
     
         12 . The biosensor as defined in  claim 6 , wherein
 the metallic salt is either or both of magnesium nitrate and calcium nitrate.   
     
     
         13 . A biosensor for measuring the concentration of a specific substance in a sample solution, wherein
 organic acid or organic acid salt which has at least one carboxyl group in its molecule is included in a previously-provided reagent layer so that it is dissolved in the sample solution and specifically reacts to the specific substance in the sample solution.   
     
     
         14 . The biosensor as defined in  claim 13 , wherein
 the concentration of the specific substance is measured employing electrodes comprising at least a working electrode and a counter electrode provided on an insulating support.   
     
     
         15 . The biosensor as defined in  claim 14 , wherein
 the reagent layer is formed on the electrodes or so that the electrodes are arranged in a diffusion area where a reagent in the reagent layer is dissolved and diffused in the sample solution, and the reagent layer includes at least an enzyme and an electron transfer agent.   
     
     
         16 . The biosensor as defined in  claim 13 , wherein the organic acid is aliphatic carboxylic acid, carbocyclic carboxylic acid, or heterocyclic carboxylic acid, or a substitution product or derivative of the organic acid. 
     
     
         17 . The biosensor as defined in  claim 13 , wherein the carboxylic acid is one of glutaric acid, adipic acid, phthalic acid, and benzoic acid, or a combination of these acids. 
     
     
         18 . A biosensor for measuring the concentration of a specific substance in a sample solution, wherein
 organic acid or organic acid salt which has at least one carboxyl group and one amino group in its molecule is included in a previously-provided reagent layer so that it is dissolved in the sample solution and specifically reacts to the specific substance in the sample solution.   
     
     
         19 . The biosensor as defined in  claim 18 , wherein
 the concentration of the specific substance is measured employing electrodes comprising at least a working electrode and a counter electrode provided on an insulating support.   
     
     
         20 . The biosensor as defined in  claim 19 , wherein
 the reagent layer is formed on the electrodes or so that the electrodes are arranged in a diffusion area where a reagent in the reagent layer is dissolved and diffused in the sample solution, and the reagent layer includes at least an enzyme and an electron transfer agent.   
     
     
         21 . The biosensor as defined in  claim 18 , wherein the organic acid is amino acid, or a substitution product or derivative of amino acid. 
     
     
         22 . The biosensor as defined in  claim 18 , wherein the amino acid is one of glycine, serine, proline, threonine, lysine, and taurine, or a combination of these acids. 
     
     
         23 . A biosensor for measuring the concentration of a specific substance in a sample solution, wherein
 a combination of at least two of sugar alcohol, metallic salt, organic acid or organic acid salt which has at least one carboxyl group in its molecule, and organic acid or organic acid salt which has at least one carboxyl group and one amino group in its molecule, is included in a previously-provided reagent layer so that it is dissolved in the sample solution and specifically reacts to the specific substance in the sample solution.   
     
     
         24 . The biosensor as defined in  claim 1 , wherein the reagent layer further includes a hydrophilic polymer. 
     
     
         25 . The biosensor as defined in  claim 6 , wherein the reagent layer further includes a hydrophilic polymer. 
     
     
         26 . The biosensor as defined in  claim 13 , wherein the reagent layer further includes a hydrophilic polymer. 
     
     
         27 . The biosensor as defined in  claim 18 , wherein the reagent layer further includes a hydrophilic polymer. 
     
     
         28 . The biosensor as defined in  claim 23 , wherein the reagent layer further includes a hydrophilic polymer.