US5804048A
Expired / Lapsed
US
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Electrode assembly for assaying glucose
Assignee: Segars California Partners LP
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Filing: 1996-08-15
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Granted: 1998-09-08
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Expires: 2016-08-15
Abstract
Abstract An improved electrode assembly is disclosed for use in assaying glucose in solution, e.g., in undiluted whole blood. The assembly includes a sensor electrode and a special overlaying multi-layer membrane that can be sterilized by gamma radiation without reducing the activity of a glucose oxidase enzyme located in an intermediate layer of the membrane. An outer layer of the membrane is formed with microscopic pores having a predetermined density and predetermined size, for reliably controlling the flux of glucose and oxygen from the solution to the intermediate layer, where they react in the presence of the glucose oxidase enzyme to form reactions products that include hydrogen peroxide. The outer layer thus functions as a diffusion barrier, to eliminate the adverse effects of any oxygen deficit that might be present. In addition, an inner layer of the membrane functions as an interference barrier, for controlling the permeation of the hydrogen peroxide reaction product to the underlying electrode. The inner layer includes a relatively thick, porous backing film, formed for example of porous polyester, and a relatively thin, porous overlaying film, formed for example of polysulfone.
Inventors
- 👤 David K. Wong
- 👤 Joseph Y. Lucisano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:58
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/001; C12Q1/002; C12Q1/005; C12Q1/006; G; G01; G01N; G01N27/00; G01N27/26; G01N27/28; G01N27/30; G01N27/327; G01N27/3271; Y; Y10; Y10S; Y10S435/00; Y10S435/817
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
191 words
An electrode assembly for use in assaying glucose in a solution, the electrode assembly comprising: a sensor electrode; and a membrane assembly overlaying the sensor electrode the membrane assembly including an outer, diffusion-barrier layer positioned to contact the solution, the outer layer having a substantially uniform thickness and having a distribution of pores of a specific density and of a size in the range of 0.0125 to 0.0200 microns. an inner, interference-barrier layer contacting a face of the sensor electrode and having a substantially uniform thickness, wherein the inner layer includes a relatively thick, porous backing film and a relatively thin, porous overlaying film that overlays the backing film, and an immobilized glucose oxidase layer interposed between the outer and inner layers and having a substantially uniform thickness, wherein the outer layer is configured to allow glucose and oxygen to diffuse through it to reach the glucose oxidase layer, where the glucose and oxygen react to form reaction products that include hydrogen peroxide, and wherein the inner layer is configured to have a permeability sufficient to pass hydrogen peroxide from the glucose oxidase layer to the face of the sensor electrode.
Claim 2
Dependent Claim
191 words
An electrode assembly for use in assaying glucose in a solution, the electrode assembly comprising: a sensor electrode; and a membrane assembly overlaying the sensor electrode the membrane assembly including an outer, diffusion-barrier layer positioned to contact the solution, the outer layer having a substantially uniform thickness and having a distribution of pores of a specific density and of a size in the range of 0.0125 to 0.0200 microns. an inner, interference-barrier layer contacting a face of the sensor electrode and having a substantially uniform thickness, wherein the inner layer includes a relatively thick, porous backing film and a relatively thin, porous overlaying film that overlays the backing film, and an immobilized glucose oxidase layer interposed between the outer and inner layers and having a substantially uniform thickness, wherein the outer layer is configured to allow glucose and oxygen to diffuse through it to reach the glucose oxidase layer, where the glucose and oxygen react to form reaction products that include hydrogen peroxide, and wherein the inner layer is configured to have a permeability sufficient to pass hydrogen peroxide from the glucose oxidase layer to the face of the sensor electrode.
Claim 3
Dependent Claim
38 words
An electrode assembly as defined in claim 1, wherein the outer layer is configured to allow the diffusion of oxygen from the solution to a substantially greater degree than it allows the diffusion of glucose from the solution.
Claim 4
Dependent Claim
30 words
An electrode assembly as defined in claim 2, wherein the outer layer is configured to be at least about 400 times more permeable to oxygen than it is to glucose.
Claim 5
Dependent Claim
16 words
An electrode assembly as defined in claim 2, wherein the outer layer is formed of polycarbonate.
Claim 6
Dependent Claim
19 words
An electrode assembly as defined in claim 2, wherein the outer layer has a thickness of about 6 microns.
Claim 7
Dependent Claim
29 words
An electrode assembly as defined in claim 2, wherein the pores in the outer layer contribute about 0.003 percent to about 0.015 percent of the outer layer's total porosity.
Claim 8
Dependent Claim
20 words
An electrode assembly as defined in claim 1, wherein the pores of the outer layer have a substantially random distribution.
Claim 9
Dependent Claim
32 words
An electrode assembly as defined in claim 1, wherein the backing film of the inner layer is formed of polyester and the overlaying film of the inner layer is formed of polysulfone.
Claim 10
Dependent Claim
27 words
An electrode assembly as defined in claim 1, wherein the backing film and overlaying film of the inner layer have a combined thickness of about 15 microns.
Claim 11
Dependent Claim
23 words
An electrode assembly as defined in claim 1, wherein the immobilized glucose oxidase layer carries glucose oxidase and albumin, in prescribed relative proportions.
Claim 12
Dependent Claim
18 words
An electrode assembly as defined in claim 10, wherein the weight ratio of glucose oxidase:albumin is about 85:65.
Claim 13
Dependent Claim
174 words
An electrode assembly for use in assaying glucose in a solution, the electrode assembly comprising: a sensor electrode; and a membrane assembly overlaying the sensor electrode, the membrane assembly including an outer, diffusion-barrier layer positioned to contact the solution, the outer layer having a uniform thickness and a distribution of pores of a specific density and a specific size, an inner, interference-barrier layer contacting a face of the sensor electrode and including a relatively thick, porous backing film and a relatively thin, porous overlaying film that overlays the backing film, the two films together having a uniform thickness, and an immobilized glucose oxidase layer interposed between the outer and inner layers, wherein the outer layer is configured to allow glucose and oxygen to diffuse through it to reach the glucose oxidase layer, where the glucose and oxygen react to form reaction products that include hydrogen peroxide, and wherein the inner layer is configured to have a permeability sufficient to pass hydrogen peroxide from the glucose oxidase layer to the face of the sensor electrode.
Claim 14
Dependent Claim
174 words
An electrode assembly for use in assaying glucose in a solution, the electrode assembly comprising: a sensor electrode; and a membrane assembly overlaying the sensor electrode, the membrane assembly including an outer, diffusion-barrier layer positioned to contact the solution, the outer layer having a uniform thickness and a distribution of pores of a specific density and a specific size, an inner, interference-barrier layer contacting a face of the sensor electrode and including a relatively thick, porous backing film and a relatively thin, porous overlaying film that overlays the backing film, the two films together having a uniform thickness, and an immobilized glucose oxidase layer interposed between the outer and inner layers, wherein the outer layer is configured to allow glucose and oxygen to diffuse through it to reach the glucose oxidase layer, where the glucose and oxygen react to form reaction products that include hydrogen peroxide, and wherein the inner layer is configured to have a permeability sufficient to pass hydrogen peroxide from the glucose oxidase layer to the face of the sensor electrode.
Claim 15
Dependent Claim
32 words
An electrode assembly as defined in claim 12, wherein the backing film of the inner layer is formed of polyester and the overlaying film of the inner layer is formed of polysulfone.
Claim 16
Dependent Claim
27 words
An electrode assembly as defined in claim 12, wherein the backing film and overlaying film of the inner layer have a combined thickness of about 15 microns.
Claim 17
Dependent Claim
26 words
An electrode assembly as defined in claim 12, wherein the pores in the outer layer have a size in the range of 0.0125 to 0.0200 microns.
Claim 18
Dependent Claim
23 words
An electrode assembly as defined in claim 12, wherein the immobilized glucose oxidase layer carries glucose oxidase and albumin, in prescribed relative proportions.
Claim 19
Dependent Claim
18 words
An electrode assembly as defined in claim 16, wherein the weight ratio of glucose oxidase:albumin is about 85:65.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-09-07 | 2002-03-09 | 2002-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-07 | 2006-03-09 | 2006-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-09-07 | 2010-03-09 | 2010-09-08 | $7700.00 | Window Closed / Lapsed |