Patent EP0327018A2 successfully refreshed from Google Patents.
EP0327018A2
Expired / Lapsed
EP
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Enzyme Electrode
Assignee: Nova Biomedical Corp
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Filing: 1989-01-31
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Granted: —
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Expires: 2009-01-31
Abstract
Abstract Disclosed is a method of assaying a high concentration of a substance in a liquid sample with a polarographic cell. The cell contains an electrode assembly that includes a reference electrode and a hydrogen peroxide sensor electrode having a laminated membrane covering the liquid sample contacting face of the sensor electrode. The laminated membrane includes an outer membrane permeable to the substance and oxygen, an inner membrane permeable to hydrogen peroxide and located adjacent the face of the sensor electrode, and an enzyme layer between the inner and outer membrane; the enzyme in the enzyme layer can oxidize the substance to generate hydrogen peroxide. The method includes contacting the outer membrane with the liquid sample; permitting the substance and oxygen in the liquid sample to pass through the outer membrane to contact the enzyme layer so that where the substance is oxidized to generate hydrogen peroxide; permitting the generated hydrogen peroxide to pass through the inner membrane to contact the sensor electrode; and ensuring that the supply of oxygen in the enzyme layer relative to the supply of glucose is sufficient to produce an equilibrium concentration of hydrogen peroxide, which generates a steady state response at the sensor electrode proportional to the concentration of the substance in the liquid sample.
Inventors
- 👤 Chung Chang Young
- 👤 Handani Winarta
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 19:42
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/001; C12Q1/005
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
211 words
An electrode assembly for use in a polarographic cell for assay of a substance in a liquid sample, said assembly comprising a reference electrode and a hydrogen peroxide sensor electrode having a laminated membrane covering the liquid sample-contacting face of said sensor electrode, said laminated membrane comprising an outer membrane adjacent said liquid sample, an inner membrane adjacent the face of said sensor electrode, and an enzyme layer between said inner membrane and said outer membrane, said enzyme layer comprising an enzyme that oxidizes said substance to generate hydrogen peroxide, said inner membrane having a permeability to hydrogen peroxide sufficiently great to ensure passage of hydrogen peroxide to said face of said sensor electrode, and said outer membrane having pores that allow passage of said substance and oxygen from said liquid sample to said enzyme layer, the thickness of said outer membrane and the size of said pores being selected so that said passage of said substance is sufficiently hindered relative to said passage of said oxygen that a steady state response with said electrode assembly can be obtained at substance concentrations in said liquid sample of at least 100 mg/dl where the oxygen concentration is equivalent to the oxygen concentration in a plasma sample derived from a normal human subject.
Claim 2
Dependent Claim
211 words
An electrode assembly for use in a polarographic cell for assay of a substance in a liquid sample, said assembly comprising a reference electrode and a hydrogen peroxide sensor electrode having a laminated membrane covering the liquid sample-contacting face of said sensor electrode, said laminated membrane comprising an outer membrane adjacent said liquid sample, an inner membrane adjacent the face of said sensor electrode, and an enzyme layer between said inner membrane and said outer membrane, said enzyme layer comprising an enzyme that oxidizes said substance to generate hydrogen peroxide, said inner membrane having a permeability to hydrogen peroxide sufficiently great to ensure passage of hydrogen peroxide to said face of said sensor electrode, and said outer membrane having pores that allow passage of said substance and oxygen from said liquid sample to said enzyme layer, the thickness of said outer membrane and the size of said pores being selected so that said passage of said substance is sufficiently hindered relative to said passage of said oxygen that a steady state response with said electrode assembly can be obtained at substance concentrations in said liquid sample of at least 100 mg/dl where the oxygen concentration is equivalent to the oxygen concentration in a plasma sample derived from a normal human subject.
Claim 3
Dependent Claim
13 words
The electrode of claim 1 wherein said liquid sample comprises plasma or serum.
Claim 4
Dependent Claim
11 words
The electrode of claim 1 wherein said liquid sample comprises urine.
Claim 5
Dependent Claim
18 words
The electrode of claim 1 wherein said outer membrane has a thickness of between 10 and 100 µ.
Claim 6
Dependent Claim
14 words
The electrode of claim 4 wherein said thickness is between 10 and 20 µ.
Claim 7
Dependent Claim
30 words
The electrode of claim 1 wherein said outer membrane has a plurality of layers, and wherein at least one said layer has a pore size of less than 0.125 µ.
Claim 8
Dependent Claim
55 words
The electrode of claim 1 wherein said liquid sample comprises whole blood which includes catalase capable of degrading hydrogen peroxide, said outer membrane being of sufficient thickness to impair the passage of hydrogen peroxide from said enzyme layer to said whole blood to an extent great enough to permit said steady state to be reached.
Claim 9
Dependent Claim
18 words
The electrode of claim 7 wherein said outer membrane has a thickness of between 15 and 100 µ.
Claim 10
Dependent Claim
18 words
The electrode of claim 1 wherein the substance concentration in said liquid sample is at least 200 mg/dl.
Claim 11
Dependent Claim
16 words
The electrode of claim 1 wherein said substance is glucose and said enzyme is glucose oxidase.
Claim 12
Dependent Claim
16 words
The electrode of claim 1 wherein said substance is lactate and said enzyme is lactate oxidase.
Claim 13
Dependent Claim
16 words
The electrode of claim 1 wherein said substance is alcohol and said enzyme is alcohol oxidase.
Claim 14
Dependent Claim
16 words
The electrode of claim 1 wherein said substance is cholesterol and said enzyme is cholesterol oxidase.
Claim 15
Dependent Claim
14 words
The electrode of claim 1 wherein said liquid sample is an undiluted body fluid.
Claim 16
Independent Claim
221 words
A method of assaying a high concentration of a substance in a liquid sample with a polarographic cell that includes an electrode assembly comprising a reference electrode and a hydrogen peroxide sensor electrode having a laminated membrane covering the liquid sample contacting face of said sensor electrode, said laminated membrane comprising an outer membrane permeable to said substance and oxygen, an inner membrane permeable to hydrogen peroxide and located adjacent the face of said sensor electrode, and an enzyme layer between said inner membrane and said outer membrane, said enzyme layer comprising an enzyme that can oxidize said substance to generate hydrogen peroxide, said method comprising contacting said outer membrane with said liquid sample; permitting said substance and oxygen in said liquid sample to pass through said outer membrane to said enzyme layer so that said enzyme oxidizes said substance to generate hydrogen peroxide; permitting said generated hydrogen peroxide to pass through said inner layer to contact said face of said sensor electrode; and ensuring that the supply of said oxygen in said enzyme layer is sufficient relative to the supply of said substance in said enzyme layer to generate an equilibrium concentration of hydrogen peroxide in said enzyme layer and said inner layer to obtain a steady state response proportional to the concentration of said substance in said liquid sample.
Claim 17
Independent Claim
221 words
A method of assaying a high concentration of a substance in a liquid sample with a polarographic cell that includes an electrode assembly comprising a reference electrode and a hydrogen peroxide sensor electrode having a laminated membrane covering the liquid sample contacting face of said sensor electrode, said laminated membrane comprising an outer membrane permeable to said substance and oxygen, an inner membrane permeable to hydrogen peroxide and located adjacent the face of said sensor electrode, and an enzyme layer between said inner membrane and said outer membrane, said enzyme layer comprising an enzyme that can oxidize said substance to generate hydrogen peroxide, said method comprising contacting said outer membrane with said liquid sample; permitting said substance and oxygen in said liquid sample to pass through said outer membrane to said enzyme layer so that said enzyme oxidizes said substance to generate hydrogen peroxide; permitting said generated hydrogen peroxide to pass through said inner layer to contact said face of said sensor electrode; and ensuring that the supply of said oxygen in said enzyme layer is sufficient relative to the supply of said substance in said enzyme layer to generate an equilibrium concentration of hydrogen peroxide in said enzyme layer and said inner layer to obtain a steady state response proportional to the concentration of said substance in said liquid sample.
Claim 18
Dependent Claim
40 words
The method of claim 15 wherein said supply of oxygen is ensured by using an outer membrane having a thickness and pore size that hinders said passage of said substance through said outer membrane relative to the passage of oxygen.
Claim 19
Dependent Claim
13 words
The method of claim 15 wherein said liquid sample comprises plasma or serum.
Claim 20
Dependent Claim
11 words
The method of claim 15 wherein said liquid sample comprises urine.
Claim 21
Dependent Claim
56 words
The method of claim 15 wherein said liquid sample comprises whole blood, which includes catalase, said method further comprising delaying the passage of said hydrogen peroxide from said enzyme layer through said outer membrane sufficiently so that the oxidation of hydrogen peroxide by said catalase in said whole blood does not prevent said steady state response.
Claim 22
Dependent Claim
30 words
The method of claim 19 wherein said passage of hydrogen peroxide is sufficiently delayed by using an outer membrane that is thick enough to cause the delay in said passage.
Claim 23
Dependent Claim
16 words
The method of claim 15 wherein said substance is glucose and said enyzme is glucose oxidase.
Claim 24
Dependent Claim
16 words
The method of claim 15 wherein said substance is lactate and said enzyme is lactate oxidase
Claim 25
Dependent Claim
16 words
The method of claim 15 wherein said substance is alcohol and said enzyme in alcohol oxidase.
Claim 26
Dependent Claim
16 words
The method of claim 15 wherein said substance is cholesterol and said enzyme is cholesterol oxidase.
Claim 27
Dependent Claim
13 words
The method of claim 15 wherein said liquid sample comprises a body fluid.
Claim 28
Dependent Claim
22 words
The method of claim 15 wherein said substance is present in said liquid sample at a concentration of at least 100 mg/dl.
Claim 29
Dependent Claim
22 words
The method of claim 15 wherein said substance is present in said liquid sample at a concentration of at least 200 mg/dl.
References Cited (Backward Citations)
No citation records indexed.
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