Biosensor

Abstract

One object of the present invention is to provide a biosensor and a production method therefor, by which hydrogel that enables immobilization of a physiologically active substance can be conveniently produced using safe raw materials. The present invention provides a biosensor which comprises a substrate having a metal layer on its surface, wherein a hydrophilic polymer having a reactive functional group capable of reacting with a hydroxyl group or an amino group of a physiologically active substance is bound to the metal layer directly or indirectly via an intermediate layer.

1 . A biosensor which comprises a substrate having a metal layer on its surface, wherein a hydrophilic polymer having a reactive functional group capable of reacting with a hydroxyl group or an amino group of a physiologically active substance is bound to the metal layer directly or indirectly via an intermediate layer.  
     
     
         2 . The biosensor according to  claim 1 , wherein the reactive functional group of the hydrophilic polymer is a vinylsulfone group or a precursor thereof.  
     
     
         3 . The biosensor according to  claim 1 , wherein the reactive functional group of the hydrophilic polymer is a dichlorotriazine group.  
     
     
         4 . The biosensor according to  claim 1 , which is obtained by forming a dense layer on the metal surface using an alkanethiol having a reactive group at its terminus or a disulfide that is an oxidized product of the alkanethiol, and then allowing the reactive group at the terminus of the alkanethiol to react with a hydrophilic polymer having a reactive functional group capable of reacting with a hydroxyl group or an amino group of a physiologically active substance.  
     
     
         5 . The biosensor according to  claim 1 , wherein a carboxylic acid is introduced by allowing the reactive functional groups of the hydrophilic polymer to react with an amino acid.  
     
     
         6 . The biosensor according to  claim 1 , which is used in surface plasmon resonance analysis.  
     
     
         7 . A method for producing the biosensor according to  claim 1 , which comprises a step of chemically binding a hydrophilic polymer having a reactive functional group capable of reacting with a hydroxyl group or an amino group of a physiologically active substance to the surface of a substrate having a metal layer on its surface directly or indirectly via an intermediate layer.  
     
     
         8 . A method for detecting or measuring a substance interacting with a physiologically active substance, which comprises a step of allowing a test substance to come into contact with the biosensor of  claim 1  to the surface of which the physiologically active substance binds via a covalent bond.  
     
     
         9 . A biosensor which comprises a surface having a reactive group capable of chemically immobilizing a physiologically active substance and a cationic group.  
     
     
         10 . The biosensor according to  claim 9 , wherein the surface comprising a reactive group capable of chemically immobilizing a physiologically active substance and a cationic group is a surface having a water-soluble polymer bound thereto, a surface having a hydrophobic polymer bound thereto, or a surface having a self-assembling monolayer film formed thereon.  
     
     
         11 . The biosensor according to  claim 9 , wherein the reactive group capable of chemically immobilizing a physiologically active substance is a vinylsulfone group or a precursor thereof, a halotriazine group, an epoxy group, a carboxylic active ester group, an aldehyde group, an isocyanate group, or an acetoacetyl group.  
     
     
         12 . The biosensor according to  claim 9 , wherein the cationic group is an onium or a precursor thereof.  
     
     
         13 . The biosensor according to  claim 9 , which is used in surface plasmon resonance analysis.  
     
     
         14 . A method for immobilizing a physiologically active substance, which comprises allowing a solution containing a physiologically active substance and having a pH that is the isoelectric point or higher to come into contact with a surface having a reactive group capable of chemically immobilizing a physiologically active substance and a cationic group.  
     
     
         15 . A method for detecting or measuring a substance interacting with a physiologically active substance, which comprises a step of allowing a test substance to come into contact with the biosensor of  claim 9  to the surface of which the physiologically active substance binds via a covalent bond.  
     
     
         16 . A biosensor which comprises a surface having a reactive group capable of chemically immobilizing a physiologically active substance and an anionic group having an acid dissociation constant that is lower than that of a carboxyl group.  
     
     
         17 . The biosensor according to  claim 16 , wherein the surface having a reactive group capable of chemically immobilizing a physiologically active substance and an anionic groups having an acid dissociation constant that is lower than that of a carboxyl group is a surface having a water-soluble polymer bound thereto, a surface having a hydrophobic polymer bound thereto, or a surface having a self-assembling monolayer film formed thereon.  
     
     
         18 . The biosensor according to  claim 16 , which is obtained by coating a substrate with a polymer having a reactive group capable of chemically immobilizing a physiologically active substance and an anionic group having an acid dissociation constant that is lower than that of a carboxyl group.  
     
     
         19 . The biosensor according to  claim 16 , wherein the reactive group capable of chemically immobilizing a physiologically active substance is a vinylsulfone group or a precursor thereof, a halotriazine group, an epoxy group, a carboxylic active ester group, an aldehyde group, an isocyanate group, or an acetoacetyl group.  
     
     
         20 . The biosensor according to  claim 16 , wherein the anionic group having an acid dissociation constant that is lower than that of a carboxyl group is a sulfuric ester group, a phosphoric ester group, or a sulfonic acid group.  
     
     
         21 . The biosensor according to  claim 16 , which is used in surface plasmon resonance analysis.  
     
     
         22 . A method for immobilizing a physiologically active substance, which comprises allowing a solution containing a physiologically active substance to come into contact with a surface having a reactive group capable of chemically immobilizing a physiologically active substance and an anionic group having an acid dissociation constant that is lower than that of a carboxyl group.  
     
     
         23 . A method for detecting or measuring a substance interacting with a physiologically active substance, which comprises a step of allowing a test substance to come into contact with the biosensor of  claim 16  to the surface of which the physiologically active substance binds via a covalent bond.  
     
     
         24 . An agent for immobilizing a physiologically active substance, which comprises a polymer having, within a molecule, a reactive group capable of chemically immobilizing a physiologically active substance and an cationic group.  
     
     
         25 . The agent for immobilizing a physiologically active substance according to  claim 24 , wherein the reactive group capable of chemically immobilizing a physiologically active substance is a vinylsulfone group or a dichlorotriazine group.  
     
     
         26 . The agent for immobilizing a physiologically active substance according to  claim 24 , wherein the cationic group is a primary amine salt, a secondary amine salt, a tertiary amine salt, or a quaternary ammonium compound.  
     
     
         27 . The agent for immobilizing a physiologically active substance according to  claim 24 , wherein the polymer is a vinyl polymer, a polymer obtained by copolymerization of acrylamide monomer or (meth)acrylamide monomer, or a polysaccharide or a derivative thereof.  
     
     
         28 . A method for immobilizing a physiologically active substance, which comprises allowing a physiologically active substance to come into contact with a substrate having the agent for immobilizing a physiologically active substance according to  claim 24  on its surface so as to chemically bind the physiologically active substance to the agent for immobilizing a physiologically active substance.