Electron-Conducting Crosslinked Polyaniline-Based Redox Hydrogel, and Method of Making

Abstract

A polymer matrix that may coated on an electrode is created by co-crosslinking (1) an adduct of a polyaniline formed by templated oxidative polymerization on a polymer acid; (2) a water-soluble crosslinker; and (3) a redox enzyme. The polymer matrix may be hydrated, and the absorbed water may make it permeable to, for example, glucose. The polyaniline may be polyaniline itself or a substituted polyaniline; the water-soluble crosslinker may be poly(ethylene glycol) diglycidyl ether, and the redox enzyme may be glucose oxidase. The polymer matrix may be produced by co-crosslinking (1) an adduct of an electrically conductive polymer and a polymer acid; (2) a water-soluble crosslinker; and (3) a redox enzyme in a single step at an about neutral pH, curing by drying. After hydration, the crosslinked polymer matrix may form a 3-dimensional glucose-permeable bioelectrocatalyst, catalyzing the electrooxidation of glucose.

1 - 21 . (canceled) 
     
     
         22 . A hydrogel matrix comprising a polyaniline crosslinked with a polymer acid and a redox enzyme through a crosslinker. 
     
     
         23 . The hydrogel matrix according to  claim 22 , wherein the polyaniline is a ring-substituted polyaniline. 
     
     
         24 . The hydrogel matrix according to  claim 23 , wherein the ring-substituted polyaniline is a compound selected from the group consisting of poly-meta-toluidine, poly-ortho-toluidine, poly-ortho-fluoroaniline, poly-ortho-methoxyaniline, poly-ortho,ortho′-dimethylaniline. 
     
     
         25 . The hydrogel matrix according to  claim 23 , wherein the ring-substituted polyaniline comprises an electron donating substituent. 
     
     
         26 . The hydrogel matrix according to  claim 25 , wherein the electron donating substituent is an alkyl, phenyl, alkoxy or amino substituent. 
     
     
         27 . The hydrogel matrix according to  claim 23 , wherein the ring-substituted polyaniline comprises an electron withdrawing substituent. 
     
     
         28 . The hydrogel matrix according to  claim 27 , wherein the electron withdrawing substituent is a nitro, nitrile or halogen substituent. 
     
     
         29 . The hydrogel matrix according to  claim 22 , wherein the polyaniline has a molecular weight of from 2 kilodalton (kDa) to 50 kDa. 
     
     
         30 . The hydrogel matrix according to  claim 22 , wherein the polymer acid is poly(2-acrylamido-2-methyl-propane sulfonic acid) (PAAMSA). 
     
     
         31 . The hydrogel matrix according to  claim 25 , wherein the polyaniline and PAAMSA are present in a molar ratio of from about 1:0.7 to about 1:0.99. 
     
     
         32 . The hydrogel matrix according to  claim 22 , wherein the crosslinker is a water soluble crosslinker. 
     
     
         33 . The hydrogel matrix according to  claim 27 , wherein the water soluble crosslinker comprises poly(ethylene glycol)diglycidyl ether. 
     
     
         34 . The hydrogel matrix according to  claim 27 , wherein the water-soluble crosslinker is present in an amount of from about 2 weight % to about 30 weight %, based upon the dry weight of the polymer matrix. 
     
     
         35 . The hydrogel matrix according to  claim 22 , wherein the redox enzyme is selected from the group consisting of a flavoenzyme, a heme enzyme, and a PQQ enzyme. 
     
     
         36 . The hydrogel matrix according to  claim 22 , wherein the redox enzyme is selected from the group consisting of glucose oxidase, glucose dehydrogenase, and peroxidase. 
     
     
         37 . The hydrogel matrix according to  claim 22 , wherein the redox enzyme has an apparent Michaelis-constant obtained from an Edi-Hofstee plot of greater than 10 mM glucose. 
     
     
         38 . The hydrogel matrix according to  claim 22 , wherein the matrix comprises at least two enzymes, wherein a first enzyme is an enzyme which catalyzes a reaction to form a substrate for a second enzyme, and wherein the second enzyme is a redox enzyme. 
     
     
         39 . The hydrogel matrix according to  claim 22 , wherein the redox enzyme is present in an amount of from greater than 0 weight % to about 60 weight %, based upon the dry weight of the polymer matrix.