Immobilized enzyme electrodes
First Claim
1. In an enzyme electrode comprisinga) an electrically conductive support member comprising a porous, electrically conductive layer of resin-bonded carbon or graphite particles having a particle size in the range of about 3 to about 50 nm and having dispersed throughout said layer and in intimate contact with said carbon or graphite particles, finely-divided particles of or containing a platinum group metal having a particle size in the range of about 15 to 25 Angstroms, said carbon or graphite particles and said platinum group metal or metal-containing particles being bonded to-gether by a synthetic resin into a heterogeneous, porous substrate consisting essentially of resin-bonded carbon or graphite particles having said platinum group metal or metal-containing particles distributed uniformly throughout said layer, andb) an effective amount of an enzyme uniformly distributed throughout said porous layer and in intimate contact with said carbon or graphite particles and said platinum group metal or metal-containing particles,said electrode being amperometrically and directly responsive to the activity of said enzyme when the electrode is immersed at an applied fixed potential in a liquid sample containing a substrate for the enzyme, an improvement which comprises using, as said metal or metal-containing particles, particles selected from the group consisting of i) particles consisting entirely of platinum oxide, and ii) particles of platinum that have been oxidized to provide a surface film of platinum oxide on the surface of the particles.
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Accused Products
Abstract
Enzyme electrodes are described which are of reduced sensitivity to alcohol. The electrodes comprise a porous resin-bonded layer of powdered carbon or graphite, onto which the enzyme is immobilized, that layer containing either finely divided platinum oxide, or finely divided platinum the surface of which is provided with a thin oxide film, e.g. by an anodisation process, the finely divided platinum oxide or anodised platinum being uniformly dispersed throughout the resin-bonded carbon or graphite layer and preferably preadsorbed onto the surface of the powdered carbon or graphite prior to bonding. Also disclosed is a method of making such electrodes by a polarization treatment of a preassembled platinized electrode.
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Citations
20 Claims
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1. In an enzyme electrode comprising
a) an electrically conductive support member comprising a porous, electrically conductive layer of resin-bonded carbon or graphite particles having a particle size in the range of about 3 to about 50 nm and having dispersed throughout said layer and in intimate contact with said carbon or graphite particles, finely-divided particles of or containing a platinum group metal having a particle size in the range of about 15 to 25 Angstroms, said carbon or graphite particles and said platinum group metal or metal-containing particles being bonded to-gether by a synthetic resin into a heterogeneous, porous substrate consisting essentially of resin-bonded carbon or graphite particles having said platinum group metal or metal-containing particles distributed uniformly throughout said layer, and b) an effective amount of an enzyme uniformly distributed throughout said porous layer and in intimate contact with said carbon or graphite particles and said platinum group metal or metal-containing particles, said electrode being amperometrically and directly responsive to the activity of said enzyme when the electrode is immersed at an applied fixed potential in a liquid sample containing a substrate for the enzyme, an improvement which comprises using, as said metal or metal-containing particles, particles selected from the group consisting of i) particles consisting entirely of platinum oxide, and ii) particles of platinum that have been oxidized to provide a surface film of platinum oxide on the surface of the particles.
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14. A method of reducing the alcohol sensitivity of an enzyme electrode comprising:
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a) an electrically conductive support member comprising a porous, electrically conductive layer of resin-bonded carbon or graphite particles having a particle size of about 3 to about 50 nm, and having dispersed throughout said layer and in intimate contact with said carbon or graphite particles, finely divided particles of platinum said carbon or graphite particles and said platinum particles being bonded together by a synthetic resin into a heterogeneous porous substrate consisting essentially of resin-bonded carbon or graphite particles having said finely-divided platinum particles distributed uniformly throughout the layer, and b) an effective amount of an enzyme uniformly distributed throughout said porous layer, and in intimate contact with said carbon or graphite particles and said finely-divided platinum particles, said electrode being amperometrically and directly responsive to the activity of said enzyme when the electrode is immersed at an applied fixed potential in a liquid sample containing a substrate for the enzyme, which method comprises the step of subjecting the platinum particles to an anodization treatment, before or after incorporation into the electrically conductive layer of resin-bonded carbon or graphite particles, thereby to provide said platinum particles with an anodized surface. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification