US4975175A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Miniaturized oxygen electrode and miniaturized biosensor and production process thereof
Assignee: Fujitsu Ltd
•
Filing: 1989-06-15
•
Granted: 1990-12-04
•
Expires: 2009-06-15
Abstract
Abstract Miniaturized Clark-type oxygen electrodes includes a substrate having at least one recess groove formed on a surface thereof for receiving an electrolyte solution, and two electrodes acting as a cathode and an anode formed through an insulating layer on the surface of the substrate. Each of the electrodes is at least partially disposed in a bottom area of the recess. A solid or semi-solid, porous, electrolyte solution-containing material fills the recess, and an oxygen gas-permeable membrane covers and seals the recess and porous material received therein. Miniaturized biosensors are made using the oxygen electrode as a transducer. The oxygen electrodes and biosensors, which are extremely accurate, can be mass-produced and can be widely used in various fields such as clinical analysis, industrial processing, and in the determination of environmental conditions. The biosensors can be particularly used in clinical diagnosis and in monitoring devices for both in vivo and in vitro measurements.
Inventors
- 👤 Isao Karube
- 👤 Hiroaki Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:40
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/404; C; C12; C12Q; C12Q1/00; C12Q1/001; C12Q1/005; Y; Y10; Y10S; Y10S435/00; Y10S435/817
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
115 words
A miniaturized oxygen electrode comprising: a semiconductor substrate having outer surfaces and at least one recess formed on one of the surfaces thereof by anisotropic etching for receiving an aqueous electrolyte solution, the substrate having an insulating layer on the surfaces thereof, the recess having a bottom area; two electrodes including a cathode and an anode which are formed on the insulating layer on at least part of the outer surface of the substrate, each electrode being at least partially extended to the bottom area of the recess; a solid or semi-solid, porous, aqueous electrolyte solution-containing material filling the recess; and an oxygen gas-permeable membrane covering and sealing the recess with the porous material therein.
Claim 2
Dependent Claim
115 words
A miniaturized oxygen electrode comprising: a semiconductor substrate having outer surfaces and at least one recess formed on one of the surfaces thereof by anisotropic etching for receiving an aqueous electrolyte solution, the substrate having an insulating layer on the surfaces thereof, the recess having a bottom area; two electrodes including a cathode and an anode which are formed on the insulating layer on at least part of the outer surface of the substrate, each electrode being at least partially extended to the bottom area of the recess; a solid or semi-solid, porous, aqueous electrolyte solution-containing material filling the recess; and an oxygen gas-permeable membrane covering and sealing the recess with the porous material therein.
Claim 3
Dependent Claim
18 words
The oxygen electrode according to claim 1, wherein the semiconductor substrate is a <100 > oriented silicon substrate.
Claim 4
Dependent Claim
22 words
The oxygen electrode according to claim 2, wherein the insulating layer is a silicon oxide layer formed by oxidizing the silicon substrate.
Claim 5
Dependent Claim
18 words
The oxygen electrode according to claim 1, wherein the electrodes are formed by vacuum deposition of selected metals.
Claim 6
Dependent Claim
48 words
The oxygen electrode according to claim 1, wherein both the cathode and the anode are made of the same material and each is selected from a group consisting of gold and platinum, and the electrolyte solution in contact with the electrodes is an aqueous solution of potassium chloride.
Claim 7
Dependent Claim
59 words
The oxygen electrode according to claim 1, wherein the cathode is made of a material selected from the group consisting of gold and platinum and the anode is made of a material selected from the group consisting of silver/silver chloride, lead, and silver, and the electrolyte solution in contact with the electrodes is an aqueous solution of potassium chloride.
Claim 8
Dependent Claim
47 words
The oxygen electrode according to claim 1, wherein the cathode is made of a material selected from the group consisting of gold and platinum and the anode is made of lead, and the electrolyte solution in contact with the electrode is an aqueous solution of potassium hydroxide.
Claim 9
Dependent Claim
47 words
The oxygen electrode according to claim 1, wherein the cathode is made of a material selected from the group consisting of gold and platinum, and the anode is made of silver, and the electrolyte solution in contact with the electrodes is an aqueous solution of potassium hydroxide.
Claim 10
Dependent Claim
21 words
The oxygen electrode according to claim 1, wherein the porous material is an agarose gel having the electrolyte solution entrapped therein.
Claim 11
Dependent Claim
24 words
The oxygen electrode according to claim 1, wherein the porous material is a polymeric gel of photopolymerizable monomers having the electrolyte solution entrapped therein.
Claim 12
Dependent Claim
13 words
The oxygen electrode according to claim 10, wherein the photopolymerizable monomers include acrylamide.
Claim 13
Dependent Claim
23 words
The oxygen electrode according to claim 1, wherein the porous material is a gel of metal alkoxide having the electrolyte solution entrapped therein.
Claim 14
Dependent Claim
18 words
The oxygen electrode according to claim 1, wherein the oxygen gas-permeable membrane is a coating of silicone resin.
Claim 15
Dependent Claim
18 words
The oxygen electrode according to claim 1, wherein the oxygen gas-permeable membrane is a coating of photoresist material.
Claim 16
Dependent Claim
114 words
A process for the production of miniaturized oxygen electrodes which comprises the steps of: forming at least one recess on a semiconductor substrate having outer surfaces by photolithographic and anixotropic etching, the recess having a bottom area, forming an insulating layer on the surface of the substrate including the recess, forming two electrodes on a surface of the insulating layer such that the electrodes are on at least part of the outer surfaces and are at least partially extended to the bottom area of the recess, filling the recess with a solid or semi-solid, porous, aqueous electrolyte solution-containing material, and covering and sealing the recess containing the porous material with an oxygen gas-permeable membrane.
Claim 17
Dependent Claim
114 words
A process for the production of miniaturized oxygen electrodes which comprises the steps of: forming at least one recess on a semiconductor substrate having outer surfaces by photolithographic and anixotropic etching, the recess having a bottom area, forming an insulating layer on the surface of the substrate including the recess, forming two electrodes on a surface of the insulating layer such that the electrodes are on at least part of the outer surfaces and are at least partially extended to the bottom area of the recess, filling the recess with a solid or semi-solid, porous, aqueous electrolyte solution-containing material, and covering and sealing the recess containing the porous material with an oxygen gas-permeable membrane.
Claim 18
Dependent Claim
25 words
The production process according to claim 15, wherein the substrate is silicon and the step of forming an insulating layer comprises oxidizing the silicon substrate.
Claim 19
Dependent Claim
31 words
The production process according to claim 15, wherein the electrodes forming step comprises vacuum deposition of electrode materials selected from the group consisting of gold, platinum, silver, silver/silver chloride and lead.
Claim 20
Dependent Claim
47 words
The production process according to claim 15, wherein the filling step comprises pouring a heated solution of agarose containing the electrolyte solution into the recess and leaving the heated solution to stand for a time sufficient to form an agarose gel having the electrolyte solution entrapped therein.
Claim 21
Dependent Claim
49 words
The production process according to claim 15, wherein the filling step comprises pouring a solution of photopolymerizable monomers containing the electrolyte solution into the recess and irradiating the solution with radiations capable of inducing polymerization of the monomers to form a polymeric gel having the electrolyte solution entrapped therein.
Claim 22
Dependent Claim
28 words
The production process according to claim 19, wherein the photopolymerizable monomers are acrylamide and the filling step includes irradiating the solution with UV rays to cause polymerization thereof.
Claim 23
Dependent Claim
78 words
The production process according to claim 15, further comprising, after formation of the electrodes, coating the surface of the substrate except for the recess portion with a hydrophobic photoresist material, dipping the masked substrate in an aqueous solution of photopolymerizable monomers containing the electrolyte solution, and exposing the substrate containing the aqueous solution of monomers in the recess to radiations capable of inducing polymerization of the monomers to form a polymeric gel having the electrolyte solution entrapped therein.
Claim 24
Dependent Claim
33 words
The production process according to claim 21, further comprising exposing the substrate to the radiations after covering and closing the recess formed thereon with an evaporation-preventing means which allows passage of the radiations.
Claim 25
Dependent Claim
28 words
The production process according to claim 22, wherein the photopolymerizable monomers are acrylamide and the exposing step comprising exposing the solution to UV rays to cause polymerization thereof.
Claim 26
Dependent Claim
27 words
The production process according to claim 22, in which the photopolymerizable monomers are acrylamide and the solution thereof is exposed to UV rays to cause polymerization thereof.
Claim 27
Dependent Claim
46 words
The production process according to claim 15, wherein the filling step comprises pouring a solution of metal alkoxide containing the electrolyte solution into the recess and subjecting the solution to a sol-gel process to form a gel of metal alkoxide having the electrolyte solution entrapped therein.
Claim 28
Dependent Claim
13 words
The production process according to claim 25, wherein the metal alkoxide is tetraethoxysilane.
Claim 29
Dependent Claim
76 words
The production process according to claim 15, further comprising, after formation of the electrodes, coating the surface of the substrate except for the recess portion with a hydrophobic photoresist material, dipping the masked substrate in an aqueous solution of metal alkoxide containing the electrolyte solution, and subjecting the substrate containing the aqueous solution of metal alkoxide in the recess to a sol-gel process to form a gel of metal alkoxide having the electrolyte solution entrapped therein.
Claim 30
Dependent Claim
13 words
The production process according to claim 27, wherein the metal alkoxide is tetraethoxysilane.
Claim 31
Dependent Claim
29 words
The production process according to claim 15, wherein the covering and sealing step comprises coating the porous material-containing recess with a silicon resin to form the oxygen gas-permeable membrane.
Claim 32
Dependent Claim
29 words
The production process according to claim 15, wherein the covering and sealing step comprises coating the porous material-containing recess with a photoresist material to form the oxygen gas-permeable membrane.
Claim 33
Dependent Claim
145 words
A miniaturized biosensor comprising: an oxygen electrode having a sensitive site and including a semiconductor substrate having at least one recess having a bottom area and being formed by anisotropic etching on a surface thereof for receiving an aqueous electrolyte solution, an insulating layer formed on the substrate, two electrodes which act as a cathode and an anode and are formed on the insulating layer on the surface of the substrate and each of which electrodes is at least partially on the surface and are extended to the bottom area of the recess, and a solid or semi-solid, porous, aqueous electrolyte solution-containing material filling the recess, an oxygen gas-permeable membrane covering and sealing the recess and porous material contained therein; and an immobilized biological substance capable of catalyzing the oxidation of biochemical organic compounds and being positioned on the sensitive site of the oxygen electrode.
Claim 34
Dependent Claim
145 words
A miniaturized biosensor comprising: an oxygen electrode having a sensitive site and including a semiconductor substrate having at least one recess having a bottom area and being formed by anisotropic etching on a surface thereof for receiving an aqueous electrolyte solution, an insulating layer formed on the substrate, two electrodes which act as a cathode and an anode and are formed on the insulating layer on the surface of the substrate and each of which electrodes is at least partially on the surface and are extended to the bottom area of the recess, and a solid or semi-solid, porous, aqueous electrolyte solution-containing material filling the recess, an oxygen gas-permeable membrane covering and sealing the recess and porous material contained therein; and an immobilized biological substance capable of catalyzing the oxidation of biochemical organic compounds and being positioned on the sensitive site of the oxygen electrode.
Claim 35
Dependent Claim
13 words
The biosensor according to claim 31, wherein the biological substance is an enzyme.
Claim 36
Dependent Claim
13 words
The biosensor according to claim 31, wherein the biological substance is a microorganism.
Claim 37
Dependent Claim
20 words
The biosensor according to claim 31, wherein the biological substance is a mixture of at least two enzymes and microorganisms.
Claim 38
Dependent Claim
14 words
The biosensor according to claim 31, wherein the sensitive site is sensitive to glucose.
Claim 39
Dependent Claim
18 words
The biosensor according to claim 31, wherein the biological substance is a mixture of at least two enzymes.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-03 | 1994-06-04 | 1994-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-03 | 1998-06-04 | 1998-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-03 | 2002-06-04 | 2002-12-04 | $7700.00 | Window Closed / Lapsed |