EP0690134A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Electrochemical sensors
Assignee: Bayer Corp
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Filing: 1995-06-20
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Granted: —
•
Expires: 2015-06-20
Abstract
Abstract A solid state, multi-use electrochemical sensor having an electrically nonconductive substrate, a working electrode, and a semi-permeable membrane covering the working electrode. The working electrode includes an electrically conductive material adhered to a portion of the substrate. A first portion of the conductive material is covered with an electrically insulating dielectric coating, and a second portion of the conductive material is covered with an active layer. The active layer includes a catalytically active quantity of an enzyme carried by platinized carbon powder particles, which are distributed throughout the active layer. A sensor package for incorporating a sensor is provided.
Inventors
- 👤 Thomas C. Maley
- 👤 Steven C. Lepke
- 👤 Mark W. Boden
- 👤 Richard W. Mason
- 👤 Paul A. D'orazio
- 👤 Robert R. Mccaffrey
- 👤 Bonnie C. Dalzell
- 👤 John A. Zalenski
- 👤 Peter G. Edelman
- 👤 James E. Flaherty
- 👤 Robert B. Green
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 15:50
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; C; C12; C12Q; C12Q1/00; C12Q1/001; C12Q1/005; C12Q1/006; Y; Y10; Y10S; Y10S435/00; Y10S435/817; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49204; Y10T29/53; Y10T29/5313; Y10T29/53261; Y10T29/53265
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
207 words
A solid state, multi-use electrochemical sensor characterised in that it comprises: an electrically nonconductive substrate; a working electrode, including an electrically conductive material adhered to a portion of the said substrate, a first portion of the said conductive material being covered with an electrically insulating dielectric coating, a second portion of the said conductive material being covered with an active layer comprising a catalytically active quantity of an enzyme immobilized onto platinized carbon powder particles, the said particles being distributed substantially uniformly throughout the said active layer; a counter electrode, including a second electrically conductive material adhered to a second portion of the said substrate, a portion of the said second conductive material being covered with an electrically insulating dielectric coating, and at least one portion of the said second conductive material remaining uncovered by the said electrically insulating dielectric coating; a reference electrode, including a third electrically conductive material adhered to a third portion of the said substrate, a portion of the said third conductive material being covered with the said electrically insulating dielectric coating, and at least one portion of the said third conductive material remaining uncovered by the said electrically insulating dielectric coating; and a semi-permeable membrane covering at least the said working electrode.
Claim 2
Dependent Claim
34 words
A sensor as claimed in claim 1 wherein the said substrate is planar and comprises a material selected from ceramics, glasses, refractories and combinations thereof, preferably an alumina composite admixed with a glass binder.
Claim 3
Dependent Claim
34 words
A sensor as claimed in claim 1 or claim 2 wherein the said conductive material comprises a thick-film paste comprising a metal selected from silver, gold and platinum, preferably a high-purity, thick-film platinum paste.
Claim 4
Dependent Claim
31 words
A sensor as claimed in any of claims 1 to 3 wherein the said second electrically conductive material comprises a thick-film paste comprising a metal selected from silver, gold and platinum.
Claim 5
Dependent Claim
27 words
A sensor as claimed in any of claims 1 to 4 wherein the said dielectric coating comprises a material selected from ceramics, glasses, polymers and combinations thereof.
Claim 6
Dependent Claim
25 words
A sensor as claimed in any of claims 1 to 5 wherein the said electrically conductive materials are deposited according to a thick-film silk-screening technique.
Claim 7
Dependent Claim
29 words
A sensor as claimed in any of claims 1 to 6 wherein the said semi-permeable membrane is permeable to an analyte and comprises a mixture of silicone and silica.
Claim 8
Dependent Claim
39 words
A sensor as claimed in any of claims 1 to 7 wherein the said semi-permeable membrane is an anionically-stabilized, water-based hydroxyl end blocked polydimethylsiloxane elastomer comprising about 10.0 percent silica, by weight, preferably about 14.0 percent silica, by weight.
Claim 9
Dependent Claim
36 words
A sensor as claimed in any of claims 1 to 8 wherein the said third electrically conductive material has deposited over it a layer of silver/silver chloride and/or deposited over it a layer of cellulose acetate.
Claim 10
Dependent Claim
85 words
A sensor as claimed in any of claims 1 to 9 wherein it further comprises an interference correcting electrode, including an electrically conductive material adhered to a portion of the said substrate, a first portion of the said conductive material being covered with said electrically insulating dielectric coating, and a second portion of the said conductive material being covered with an inactive layer comprising an inactive protein immobilized onto platinized carbon powder particles, the said particles being distributed substantially uniformly throughout the said inactive layer.
Claim 11
Dependent Claim
43 words
A sensor as claimed in any of claims 1 to 10 wherein it is a glucose sensor, the said enzyme being glucose oxidase and the said semi-permeable membrane being glucose and oxygen-permeable, or is a lactate sensor, the said enzyme being lactate oxidase.
Claim 12
Dependent Claim
42 words
A sensor as claimed in any of claims 1 to 11 wherein it is adapted to operate for the lesser of one thousand (1000) uses or thirty (30) days, preferably for the less of two thousand (2000) uses or sixty (60) days.
Claim 13
Dependent Claim
72 words
A sensor package characterised in that it comprises: a housing having a recess formed therein, the said recess having a perimeter and at least one passageway connected to the said recess; a solid state, planar electrochemical sensor underlying the said recess; a gasket contacting the said recess perimeter and the said solid state, planar electrochemical sensor to form a seal therebetween; and the said housing, gasket and sensor defining a sample chamber.
Claim 14
Dependent Claim
45 words
A sensor package as claimed in claim 13 wherein it further comprises a contact lead frame assembly including the plurality of leads secured to the said frame at a first end and a recess for supporting the said electrochemical sensor at a second end thereof.
Claim 15
Dependent Claim
88 words
A sensor package as claimed in claim 13 or claim 14 wherein the said contact lead frame further comprises a stabilizer bar secured to the said plurality of leads to maintain each lead in predetermined position and align the said leads with contact pads on a surface of the said electrochemical sensor; and/or wherein the said contact lead frame assembly further comprises a recess in the said housing for receipt of the said stabilizer bar when the said plurality of leads are properly positioned within the said package.
Claim 16
Dependent Claim
28 words
A sensor package as claimed in any of claims 13 to 15 wherein it further comprises a sensor pad for supporting the said sensor in the said recess.
Claim 17
Dependent Claim
36 words
A sensor package as claimed in any of claims 13 to 16 wherein the said sample chamber further comprises a velocity compensator, which is optionally a molded part of the said housing facing the said sensor.
Claim 18
Dependent Claim
28 words
A sensor package as claimed in any of claims 13 to 17 wherein the said sample chamber has a volume of from about 3.0 to about 5.0 microliters.
Claim 19
Independent Claim
133 words
A method for forming a solid state, multi-use electrochemical sensor characterised in that it comprises: selecting an electrically nonconductive substrate; depositing an electrically conductive material onto a portion of the said substrate; depositing an active layer over a portion of the said conductive material to form a working electrode, the said active layer comprising a catalytically active quantity of an enzyme immobilized onto platinized carbon powder particles, which are distributed substantially uniformly throughout the said active layer; depositing a second electrically conductive material onto a second portion of the said substrate to form a counter electrode; depositing a third electrically conductive material onto a portion of the said substrate to form a reference electrode; and depositing a semi-permeable membrane, which may be permeable to a low molecular weight analyte, over the said electrodes.
Claim 20
Dependent Claim
85 words
A method as claimed in claim 19 wherein it further comprises depositing a fourth electrically conductive material onto a portion of the said substrate; depositing the said electrically insulating dielectric material over a portion of the said fourth conductive material; and depositing an inactive layer over a second portion of the said fourth conductive material to form an interference correcting electrode, the said inactive layer comprising an inactive protein immobilized onto platinized carbon powder particles, which are distributed substantially uniformly throughout the said inactive layer.
Claim 21
Dependent Claim
132 words
A planar electrode for use in glucose or lactate determination in vitro characterised in that it comprises an insulating base layer, a coiiductive layer, an overlying active layer and an outer protective membrane permeable to oxygen and glucose or lactate, the said active layer comprising an enzyme reactive with one of glucose or lactate and platinized carbon powder particles, the said active layer causing formation of H₂O₂ in amounts proportional to the amount of the said glucose or lactate when the said glucose or lactate is exposed to the said active layer; and the said outer protective membrane comprising a silicone compound having an additive incorporated therein for transporting the said oxygen and the said glucose or lactate therethrough, thus enabling rapid and accurate determination of the said glucose or lactate concentration.
Claim 22
Dependent Claim
35 words
An electrode as claimed in claim 21 wherein the said membrane has a plurality of thin layers; preferably the said membrane has four layers and a total thickness of less than about 65.0 microns (µm).
Claim 23
Dependent Claim
58 words
An electrode as claimed in claim 21 or claim 22 wherein the said membrane is post-treated with an anti-drying material to prolong the storage life or wet-up of the said electrode; the said anti-drying material preferably being a water soluble, hydrophilic polymer liquid, in particular polyethylene glycol having a molecular weight of between about 200 and about 600.
Claim 24
Dependent Claim
104 words
A sensor characterised in that it comprises a plurality of electrodes positioned in a sample chamber through which a fluid to be tested is flowed, the said sample chamber having a flow path, a sample inlet and outlet each having a cross-sectional area less than the cross-sectional area of a portion of the said chamber, and a velocity compensator comprising a structural barrier mounted in the said flow path between the said inlet and outlet to reduce the said cross-sectional area of the said chamber in the said flow path and substantially to maintain stability in fluid velocity when flowing through the said chamber.
Claim 25
Dependent Claim
28 words
A sensor as claimed in claim 24 wherein the said velocity compensator is positioned to extend towards the said electrodes without obstructing fluid flow over the said electrodes.
Claim 26
Dependent Claim
37 words
A sensor as claimed in claim 24 or claim 25 wherein the said chamber is a molded plastic chamber and the said velocity compensator is an integral extension thereof positioned partially to obstruct the said flow path.
Claim 27
Dependent Claim
59 words
A sensor characterised in that it is mounted in a housing and has a plurality of closely spaced electrical contacts connected to a plurality of elongated axially extending electrical leads the said leads being spaced apart by a stabilizer bar attached to the said leads which positively positions the said leads in proper position for the said electrical contacts.
Claim 28
Dependent Claim
23 words
A sensor as claimed in claim 27 wherein the said leads are resilient and are urged into contact by the said stabilizer bar.
Claim 29
Dependent Claim
67 words
A sensor as claimed in claim 27 or claim 28 wherein the said leads are attached to a lead frame base which provides a contact area for connection of the said leads to an electrical testing system, the said lead frame base optionally mounting a plurality of electrodes and forming a part of the said housing, the said leads comprising spring tips attached to the said contacts.
Claim 30
Dependent Claim
53 words
A sensor characterised in that it comprises a semi-permeable membrane for contacting a test sample, the said membrane being treated with a water soluble, hydrophilic polymer liquid anti-drying agent so that the sensor storage life or wet-up is prolonged; preferably the said anti-drying agent comprising a material selected from surfactants or polyethylene glycols.
Claim 31
Independent Claim
35 words
A method for prolonging the storage life or wet-up of an electrochemical sensor including a semi-permeable membrane characterised in that it comprises treating the semi-permeable membrane with a water soluble, hydrophilic polymer liquid anti-drying agent.
Claim 32
Dependent Claim
90 words
An electrochemical sensor characterised in that it comprises: an electrically nonconductive substrate; an interference electrode, including an electrically conductive metal adhered to a portion of the said substrate, a first portion of the said conductive material being covered with an electrically insulating dielectric coating, and a second portion of the said conductive material being covered with an inactive layer comprising an inactive protein immobilized onto platinized carbon powder particles, the said particles being distributed substantially uniformly throughout the said inactive layer; and a semi-permeable membrane covering the said interference electrode.
Claim 33
Dependent Claim
29 words
A paste for an electrochemical electrode characterised in that it comprises: (a) platinized carbon particles; (b) protein; (c) resin binder; and (d) either an enzyme or an inactive protein.
Claim 34
Dependent Claim
83 words
A process for forming a paste as claimed in claim 33 characterised in that it comprises: (a) mixing platinized carbon powder particles with a neutral buffer; (b) mixing a protein with the buffered activated carbon of (a) to form a protein-p]atinized activated carbon composition; (c) mixing a binder resin with the protein-platinized activated carbon composition of (b); (d) milling the mixture of (c) and (e) mixing either an enzyme or an inactive protein with the milled product of (d) to form a paste.
Claim 35
Dependent Claim
19 words
A cellulose acetate paste characterised in that it comprises: (a) cellulose acetate; and (b) a low vapor pressure solvent.
Claim 36
Dependent Claim
35 words
A process for forming a cellulose acetate paste as claimed in claim 35 characterised in that it comprises: mixing cellulose acetate with a low vapor pressure solvent to form a paste with a high viscosity.
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