US 8,075,760 B2Granted

Electrochemical cell

AssigneeLifeScan, Inc.

InventorsAlastair McIndoe Hodges, Thomas William Beck, Oddvar Johansen

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Abstract

A method for determining the concentration of a reduced or oxidized form of a redox species is provided. In one exemplary embodiment, an electrochemical apparatus is provided in which the apparatus includes a hollow electrochemical cell for measuring a concentration of glucose in a blood sample, a current of the cell is measured, and a concentration of a redox mediator is determined, at least in part from, a measured current of the cell. The hollow electrochemical cell can include at least one non-metal working electrode, at least one counter electrode or counter/reference electrode, and a spacer interposed between the working electrode and the counter or counter/reference electrode. In one embodiment the working electrode and the counter or counter/reference electrode are not co-planer and are separated by a distance of from about 20 microns to about 200 microns. In another embodiment the working electrode and the counter or counter/reference electrode are not co-planer and the cell has an effective cell volume of less than 1.5 microliters.

Claims26

Dependent claims

A method for determining the concentration of a reduced or oxidized form of a redox species, said method comprising the steps of:

(1) disposing a blood sample on an electrochemical apparatus comprising a hollow electrochemical cell for measuring a concentration of glucose in the blood sample, the hollow electrochemical cell comprising:
a) at least one working electrode;
b) at least one counter electrode or counter/reference electrode, wherein the working electrode and the counter electrode or counter/reference electrode are separated by a distance of from about 20 microns to about 200 microns;
and
c) a spacer interposed between the working electrode and the counter electrode or counter/reference electrode, wherein the spacer comprises a non-conductive material;
and
(2) applying an electric potential difference between the working electrode and the counter electrode or counter/reference electrode that causes at least one of:
a) a rate of electro-oxidation of a reduced form of a redox species to be determined by a rate of diffusion of the reduced form of the redox species to the working electrode, wherein the working electrode is kept sufficiently anodic when determining a concentration of the reduced form of the redox species;
and
b) a rate of electro-reduction of an oxidized form of a redox species to be determined by a rate of diffusion of the oxidized form of the redox species to the working electrode, wherein the working electrode is kept sufficiently cathodic when determining a concentration of the oxidized form of the redox species:
(3) measuring a current between the working electrode and the counter electrode or counter/reference electrode;
and
(4) determining the concentration of the reduced or oxidized form of the redox species from at least, the rate of electro-oxidation of the reduced form of the redox species when the working electrode is kept sufficiently anodic or the rate of electro-reduction of the oxidized form of the redox species when the working electrode is kept sufficiently cathodic.

10 more elements

A method for determining the concentration of a reduced or oxidized form of a redox species, said method comprising the steps of:

(1) disposing a blood sample on an electrochemical apparatus comprising a hollow electrochemical cell for measuring a concentration of glucose in the blood sample, the hollow electrochemical cell comprising:
a) at least one working electrode;
b) at least one counter electrode or counter/reference electrode, wherein the working electrode and the counter electrode or counter/reference electrode;
and
c) a spacer interposed between the working electrode and the counter electrode or counter/reference electrode, wherein the spacer comprises a non-conductive material, and wherein the hollow electrochemical cell has an effective cell volume of less than 1.5 microliters;
and
(2) applying an electric potential difference between the working electrode and the counter electrode or counter/reference electrode that causes at least one of:
a) a rate of electro-oxidation of a reduced form of a redox species to be determined by a rate of diffusion of the reduced form of the redox species to the working electrode, wherein the working electrode is kept sufficiently anodic when determining a concentration of the reduced form of the redox species;
and
b) a rate of electro-reduction of an oxidized form of a redox species to be determined by a rate of diffusion of the oxidized form of the redox species to the working electrode, wherein the working electrode is kept sufficiently cathodic when determining a concentration of the oxidized form of the redox species;
(3) measuring a current between the working electrode and the counter electrode or counter/reference electrode;
and
(4) determining the concentration of the reduced or oxidized form of the redox species from at least the rate of electro-oxidation of the reduced form of the redox species when the working electrode is kept sufficiently anodic or the rate of electro-reduction of the oxidized form of the redox species when the working electrode is kept sufficiently cathodic.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/560,773Filed 16 Sep 2009 · continuation
Priority: AU PN363919 Jun 1995
Published: US 2010/0084288 A18 Apr 2010
Granted: 13 Dec 2011
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

G01N 27/403
By investigating electrochemical variables; by using electrolysis or electrophoresis: cells and electrode assemblies
C12Q 1/004
Enzyme electrodes: mediator-assisted
G01N 27/3272
Amperometric enzyme electrodes for analytes in body fluids, e.g. glucose in blood: test elements therefor, i.e. disposable laminated substrates…
G01N 27/3273
Amperometric enzyme electrodes for analytes in body fluids, e.g. glucose in blood: devices therefor, e.g. test element readers, circuitry

Family

PCT/AU96/00365Parent of this continuation · filed 19 Jun 1996
Application09/618,515Parent of this continuation · filed 18 Jul 2000
Application10/035,924Parent of this continuation · filed 21 Dec 2001
Application10/624,823Parent of this continuation · filed 22 Jul 2003
US 6,960,289 B2Parent of this continuation · filed 1 Nov 2005
US 2010/0084288 A1Pre-grant publication · published 8 Apr 2010
US 7,604,722 B2Parent of this continuation
US 6,413,410 B1Parent of this continuation
Application08/981,385Parent of this continuation
US 6,284,125 B1Parent of this continuation
US 2002/0112969 A1Published application
US 2005/0173246 A1Published application
US 8,075,760 B2This patent

From the US filing history. Foreign family members aren’t listed.