Patent US5543024A successfully refreshed from Google Patents.
US5543024A
Expired / Lapsed
US
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Glucose sensitive FET sensor and method of making same
Assignee: Mitsubishi Electric Corp
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Filing: 1990-09-25
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Granted: 1996-08-06
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Expires: 2010-09-25
Abstract
Abstract A glucose sensitive FET sensor is provided which includes a substrate, a source electrode formed in the substrate, a drain electrode formed in the substrate, a hydrogen ion sensitive film formed on the substrate to cover the source electrode and the drain electrode, and a thin enzyme immobilized membrane formed on the hydrogen ion sensitive film and containing glucose oxidase and gluconolactonase. Also provided is a method of producing a glucose sensitive FET sensor which includes the steps of preparing an enzyme immobilized membrane as a thin film containing glucose oxidase and gluconolactonase and forming the membrane on a hydrogen ion sensitive film which is formed on a substrate to cover a source electrode and a drain electrode, both of which are formed in the substrate.
Inventors
- 👤 Yoshio Hanazato
- 👤 Mamiko Nakako
- 👤 Satoru Shiono
- 👤 Kenichi Inatomi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:49
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/001; C12Q1/005; C12Q1/006; G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/414; G01N27/4145; Y; Y10; Y10S; Y10S435/00; Y10S435/817; Y10S436/00; Y10S436/806
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
59 words
A glucose sensitive FET sensor, comprising: a substrate; a source electrode formed in said substrate; a drain electrode formed in said substrate; a hydrogen ion sensitive film formed on said substrate to cover said source electrode and said drain electrode; and a thin enzyme immobilized membrane formed on said hydrogen ion sensitive film and containing glucose oxidase and gluconolactonase.
Claim 2
Dependent Claim
59 words
A glucose sensitive FET sensor, comprising: a substrate; a source electrode formed in said substrate; a drain electrode formed in said substrate; a hydrogen ion sensitive film formed on said substrate to cover said source electrode and said drain electrode; and a thin enzyme immobilized membrane formed on said hydrogen ion sensitive film and containing glucose oxidase and gluconolactonase.
Claim 3
Dependent Claim
30 words
A glucose sensitive FET sensor as claimed in claim 1, wherein the activity ratio of said glucose oxidase to said gluconolactonase is in the range of from 1:0.5 to 1:10.
Claim 4
Dependent Claim
30 words
A glucose sensitive FET sensor as claimed in claim 1, wherein the activity ratio of said glucose oxidase to said gluconolactonase is in the range of from 1:2 to 1:3.
Claim 5
Dependent Claim
23 words
A glucose sensitive FET sensor as claimed in claim 1 wherein the thickness of said thin enzyme immobilized membrane is about 1 μm.
Claim 6
Dependent Claim
40 words
A glucose sensitive FET sensor as claimed in claim 1 wherein said film enzyme immobilized membrane is formed from 2,5-bis (4'-azide-2'-sulfobenzal) cyclopentanone sodium salt and a water soluble resin of polyvinyl pyrrolidone in addition to said glucose oxidase and gluconolactonase.
Claim 7
Dependent Claim
20 words
A glucose sensitive FET sensor as claimed in claim 5 wherein said polyvinyl pyrrolidone has a molecular weight of 360,000.
Claim 8
Independent Claim
60 words
A method of producing a glucose sensitive FET sensor, comprising the steps of: preparing an enzyme immobilized membrane as a thin film containing glucose oxidase and gluconolactonase; and forming said membrane on a hydrogen ion sensitive film which is formed on a substrate to cover a source electrode and a drain electrode both of which are formed in said substrate.
Claim 9
Independent Claim
60 words
A method of producing a glucose sensitive FET sensor, comprising the steps of: preparing an enzyme immobilized membrane as a thin film containing glucose oxidase and gluconolactonase; and forming said membrane on a hydrogen ion sensitive film which is formed on a substrate to cover a source electrode and a drain electrode both of which are formed in said substrate.
Claim 10
Dependent Claim
97 words
A method of producing a glucose sensitive FET sensor as claimed in claim 7, wherein said preparation step of said membrane further comprises the steps of: preparing an aqueous solution of a water soluble photosensitive resin which contains glucose oxidase and gluconolactonase; coating said aqueous solution of said water soluble photosensitive resin on said hydrogen ion sensitive film formed on said substrate to cover said source electrode and said drain electrode thereon; and irradiating a predetermined portion of said aqueous solution coated on said substrate with light, thereby forming an enzyme immobilized membrane as a thin film.
Claim 11
Dependent Claim
34 words
A method of producing a glucose sensitive FET sensor as claimed in claim 7, wherein the activity ratio of said glucose oxidase to said gluconolactonase is in the range of from 1:0.5 to 1:10.
Claim 12
Dependent Claim
34 words
A method of producing a glucose sensitive FET sensor as claimed in claim 7, wherein the activity ratio of said glucose oxidase to said gluconolactonase is in the range of from 1:2 to 1:3.
Claim 13
Dependent Claim
27 words
A method of producing a glucose sensitive FET sensor as claimed in claim 7, wherein the thickness of said enzyme immobilized membrane is in the micron order.
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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) | 1999-08-06 | 2000-02-05 | 2000-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-08-06 | 2004-02-05 | 2004-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-08-06 | 2008-02-05 | 2008-08-06 | $7700.00 | Window Closed / Lapsed |