US5708247A
Expired / Lapsed
US
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Disposable glucose test strips, and methods and compositions for making same
Assignee: LifeScan Scotland Ltd
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Filing: 1996-02-14
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Granted: 1998-01-13
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Expires: 2016-02-14
Abstract
Abstract An improved disposable glucose test strip for use in a test meter of the type which receives a disposable test strip and a sample of blood from a patient and performs an electrochemical analysis is made using a working formulation containing a filler, an enzyme effective to oxidize glucose, e.g., glucose oxidase, and a mediator effective to transfer electrons from the enzyme. The working formulation is printed over a conductive carbon base layer to form a working electrode. The filler, for example a silica filler, is selected to have a balance of hydrophobicity and hydrophilicity such that one drying it forms a two-dimensional network on the surface of the conductive base layer. The response of this test strip is essentially temperature independent over relevant temperature ranges and is substantially insensitive to the hematocrit of the patient.
Inventors
- 👤 Jerome F. McAleer
- 👤 David Scott
- 👤 Geoff Hall
- 👤 Manuel Alvarez-Icaza
- 👤 Elliot V. Plotkin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:48
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/001; C12Q1/002; C12Q1/004; G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/5002; Y; Y10; Y10S; Y10S435/00; Y10S435/817
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
138 words
A disposable glucose test strip for use in a test meter of the type which receives a disposable test strip and a sample of blood from a patient and performs an electrochemical analysis of the amount of glucose in the sample, comprising: (a) a substrate; (b) a reference electrode; (c) a working electrode, said working electrode comprising a conductive base layer disposed on the substrate and a first working coating disposed over the conductive base layer, said first working coating comprising a filler having both hydrophobic and hydrophilic surface regions such that it forms a network upon drying, an enzyme effective to oxidize glucose, and a mediator effective to transfer electrons from the enzyme to the conductive base layer; and (d) means for making an electrical connection between the reference and working electrode and a glucose test meter.
Claim 2
Dependent Claim
138 words
A disposable glucose test strip for use in a test meter of the type which receives a disposable test strip and a sample of blood from a patient and performs an electrochemical analysis of the amount of glucose in the sample, comprising: (a) a substrate; (b) a reference electrode; (c) a working electrode, said working electrode comprising a conductive base layer disposed on the substrate and a first working coating disposed over the conductive base layer, said first working coating comprising a filler having both hydrophobic and hydrophilic surface regions such that it forms a network upon drying, an enzyme effective to oxidize glucose, and a mediator effective to transfer electrons from the enzyme to the conductive base layer; and (d) means for making an electrical connection between the reference and working electrode and a glucose test meter.
Claim 3
Dependent Claim
12 words
The test strip of claim 1, wherein the working layer is non-conductive.
Claim 4
Dependent Claim
11 words
The test strip of claim 2, wherein the filler is silica.
Claim 5
Dependent Claim
14 words
The test strip of claim 3, wherein the conductive base layer comprises conductive carbon.
Claim 6
Dependent Claim
12 words
The test strip of claim 3, wherein the enzyme is glucose oxidase.
Claim 7
Dependent Claim
12 words
The test strip according to claim 3, wherein the mediator is ferricyanide.
Claim 8
Dependent Claim
59 words
The test strip of claim 3, wherein the first working layer is formed from an aqueous composition comprising weight 2 to 10% by weight of a binder 3 to 10% by weight of silica; 8 to 20% by weight of a mediator; and 1000 to 5000 units per gram of the aqueous composition of an enzyme for oxidizing glucose.
Claim 9
Dependent Claim
23 words
The test strip of claim 3, wherein the silica is a silica which has been modified by partial surface treatment with methyl dichlorosilane.
Claim 10
Dependent Claim
14 words
The test strip of claim 8, wherein the conductive base layer comprises conductive carbon.
Claim 11
Dependent Claim
12 words
The test strip of claim 8, wherein the enzyme is glucose oxidase.
Claim 12
Dependent Claim
11 words
The test strip of claim 8, wherein the mediator is ferricyanide.
Claim 13
Dependent Claim
59 words
The test strip of claim 8, wherein the first working layer is formed from an aqueous composition comprising weight 2 to 10% by weight of a binder 3 to 10% by weight of silica; 8 to 20% by weight of a mediator; and 1000 to 5000 units per gram of the aqueous composition of an enzyme for oxidizing glucose.
Claim 14
Dependent Claim
23 words
The test strip of claim 3, further comprising a second working layer comprising silica, a binder and a mediator but no glucose-oxidizing enzyme.
Claim 15
Dependent Claim
21 words
The test strip of claim 3, further comprising a second working layer comprising silica and a binder but no glucose-oxidizing enzyme.
Claim 16
Dependent Claim
24 words
The test strip of claim 1, further comprising a second working layer comprising a filler, a binder and a mediator but no glucose-oxidizing enzyme.
Claim 17
Dependent Claim
22 words
The test strip of claim 1, further comprising a second working layer comprising a filler and a binder but no glucose-oxidizing enzyme.
Claim 18
Dependent Claim
31 words
An aqueous composition comprising a binder, a silica filler having both hydrophobic and hydrophilic surface regions, at least one of an enzyme effective to oxidize glucose and an electron transfer mediator.
Claim 19
Dependent Claim
31 words
An aqueous composition comprising a binder, a silica filler having both hydrophobic and hydrophilic surface regions, at least one of an enzyme effective to oxidize glucose and an electron transfer mediator.
Claim 20
Dependent Claim
10 words
The composition of claim 17, wherein the filler is non-conductive.
Claim 21
Dependent Claim
44 words
An aqueous composition comprising 2 to 10% by weight of a binder; 3 to 10% by weight of silica; 8 to 20% by weight of a mediator; and 1000 to 5000 units per gram of the aqueous composition of an enzyme for oxidizing glucose.
Claim 22
Dependent Claim
44 words
An aqueous composition comprising 2 to 10% by weight of a binder; 3 to 10% by weight of silica; 8 to 20% by weight of a mediator; and 1000 to 5000 units per gram of the aqueous composition of an enzyme for oxidizing glucose.
Claim 23
Dependent Claim
15 words
The composition of claim 19, wherein the silica has both hydrophobic and hydrophilic surface regions.
Claim 24
Dependent Claim
10 words
The composition of claim 20, wherein the binder is hydroxyethylcellulose.
Claim 25
Dependent Claim
11 words
The composition of claim 19, wherein the enzyme is glucose oxidase.
Claim 26
Dependent Claim
10 words
The composition of claim 19, wherein the mediator is ferricyanide.
Claim 27
Independent Claim
95 words
A method for making a disposable test strip for the electrochemical detection of glucose, comprising the steps of: (a) applying working and reference electrode tracks to a substrate; (b) applying a conductive base layer in contact with the working electrode track; and (c) applying a working layer over the conductive base layer, wherein the working layer comprising a filler having both hydrophobic and hydrophilic surface regions such that it forms a network upon drying, an enzyme effective to oxidize glucose, and a mediator effective to transfer electrons from the enzyme to the conductive base layer.
Claim 28
Independent Claim
95 words
A method for making a disposable test strip for the electrochemical detection of glucose, comprising the steps of: (a) applying working and reference electrode tracks to a substrate; (b) applying a conductive base layer in contact with the working electrode track; and (c) applying a working layer over the conductive base layer, wherein the working layer comprising a filler having both hydrophobic and hydrophilic surface regions such that it forms a network upon drying, an enzyme effective to oxidize glucose, and a mediator effective to transfer electrons from the enzyme to the conductive base layer.
Claim 29
Dependent Claim
10 words
The method of claim 24, wherein the filler is non-conductive.
Claim 30
Dependent Claim
10 words
The method of claim 25, wherein the filler is silica.
Claim 31
Dependent Claim
13 words
The method of claim 26, wherein the conductive base layer comprises conductive carbon.
Claim 32
Dependent Claim
11 words
The method of claim 26, wherein the enzyme is glucose oxidase.
Claim 33
Dependent Claim
10 words
The method of claim 26, wherein the mediator is ferricyanide.
Claim 34
Dependent Claim
58 words
The method of claim 26, wherein the first working layer is formed from an aqueous composition comprising weight 2 to 10% by weight of a binder 3 to 10% by weight of silica; 8 to 20% by weight of a mediator; and 1000 to 5000 units per gram of the aqueous composition of an enzyme for oxidizing glucose.
Claim 35
Dependent Claim
22 words
The method of claim 30, wherein the silica is a silica which has been modified by partial surface treatment with methyl dichlorosilane.
Claim 36
Dependent Claim
66 words
A disposable glucose test strip comprising first and second electrodes which produce a current indicative of the amount of glucose in a sample applied to the strip in response to an applied voltage, wherein the amount of current generated by the electrodes in response to a given amount of glucose varies by less than 10 percent over a temperature range from 20° C. to 37° C.
Claim 37
Dependent Claim
66 words
A disposable glucose test strip comprising first and second electrodes which produce a current indicative of the amount of glucose in a sample applied to the strip in response to an applied voltage, wherein the amount of current generated by the electrodes in response to a given amount of glucose varies by less than 10 percent over a temperature range from 20° C. to 37° C.
Claim 38
Dependent Claim
64 words
A disposable glucose test strip comprising first and second electrodes which produce a current indicative of the amount of glucose in a sample applied to the strip in response to an applied voltage, wherein the amount of current generated by the electrodes in response to a given amount of glucose varies by less than 10 percent over a hematocrit range of 0 to 60%.
Claim 39
Dependent Claim
64 words
A disposable glucose test strip comprising first and second electrodes which produce a current indicative of the amount of glucose in a sample applied to the strip in response to an applied voltage, wherein the amount of current generated by the electrodes in response to a given amount of glucose varies by less than 10 percent over a hematocrit range of 0 to 60%.
Claim 40
Dependent Claim
63 words
A disposable glucose test strip comprising first and second electrodes which produces a current indicative of the amount of glucose in a sample applied to the strip in response to an applied voltage, wherein the amount of current generated by the electrodes in response to a given amount of glucose decays by less than 50% in the 5 seconds following peak current generation.
Claim 41
Dependent Claim
63 words
A disposable glucose test strip comprising first and second electrodes which produces a current indicative of the amount of glucose in a sample applied to the strip in response to an applied voltage, wherein the amount of current generated by the electrodes in response to a given amount of glucose decays by less than 50% in the 5 seconds following peak current generation.
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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) | 2001-01-12 | 2001-07-14 | 2002-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-01-12 | 2005-07-14 | 2006-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-01-12 | 2009-07-14 | 2010-01-13 | $7700.00 | Window Closed / Lapsed |