Electrochemical Sensing Method

• US 20070259262A1
• Filed: 06/29/2005
• Published: 11/08/2007
• Est. Priority Date: 06/29/2004
• Status: Abandoned Application

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Inventors: Hyland, Mark, Butler, Ronald, Broughall, John
• Application Number:
  US11/630,739
• Publication Number:
  US 20070259262A1
• Time in Patent Office: Days
• US Class Current: 429/161
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52
• CPC Class Codes: Y10T 29/49108 Electric battery cell making

Abstract

A method of confining an electroactive substance within an electrochemical cell in the form of a receptacle, said method that includes (a) providing an electrochemical cell in the form of a receptacle, the receptacle having a first open part to allow entry of a sample into the receptacle, and a second open part to allow escape of air displaced by the entering sample, the electrochemical cell having a working electrode and a counter electrode; (b) providing an electroactive substance, which substance is contained within the receptacle; (c) providing a permeable or semi-permeable membrane, including one or more layers, covering the first open part of the receptacle; and (d) inserting the sample into the receptacle through the membrane, such that (1) the electroactive substance and (2) the sample, are in contact with each other and with said working electrode; wherein the electroactive substance is confined within the receptacle during step (d). Preferably, the method additionally involves electrochemically testing a sample, by applying a voltage across the cell and measuring the resulting electrochemical response.

Claims

1. A method of confining an electroactive substance within an electrochemical cell in the form of a receptacle, said method comprising

(a) providing an electrochemical cell in the form of a receptacle, the receptacle having a first open part to allow entry of a sample into the receptacle, and a second open part to allow escape of air displaced by the entering sample, the electrochemical cell having a working electrode and a counter electrode;

(b) providing an electroactive substance, which substance is contained within the receptacle;

(c) providing a permeable or semi-permeable membrane, comprising one or more layers, covering the first open part of the receptacle; and

(d) inserting the sample into the receptacle through the membrane, such that (1) the electroactive substance and (2) the sample, are in contact with each other and with said working electrode;

wherein the electroactive substance is confined within the receptacle during step (d).

2. A method of electrochemically testing a sample according to claim 1, which method further comprises

(i) applying a potential across the electrochemical cell;

and

(ii) measuring the resulting electrochemical response;

wherein the electroactive substance is confined within the receptacle during steps (i) and (ii).

3. A method according to claim 2, wherein the electroactive substance comprises a transition metal salt.

4. A method according to claim 3, wherein the transition metal salt is a cobalt (II) salt.

5. A method according to claim 3, wherein step (ii) comprises measuring the current generated by electrochemical reaction of the transition metal salt.

6. A method according to claim 3, wherein the electroactive substance additionally comprises one or more components selected from

an electrode area normalizing agent having a current which is dependent on electrode area;

a chloride or sulfate salt; and

a wetting agent.

7. A method according to claim 1, wherein the membrane is impermeable to red blood cells and the sample is plasma or serum.

8. A method according to claim 1, wherein the electroactive substance is in dried form and wherein step (d) comprises suspending at least a part of the electroactive substance in the sample.

10. Use according to claim 9, wherein the electroactive substance is as defined in claim 3.

12. A device comprising

an electrochemical cell in the form of a receptacle, the receptacle having a first open part to allow entry of a sample into the receptacle, and a second open part to allow escape of air displaced by the entering sample, wherein the electrochemical cell has a working electrode and a counter electrode;

an electroactive substance as defined in any one of claims 3, 4, 6 or 7, the substance being contained in the receptacle;

a permeable or semi-permeable membrane, comprising one or more layers, positioned such that it covers the first open part of the receptacle;

means for applying a voltage across the cell; and

means for measuring the resulting electrochemical response across the cell.

13. A device according to claim 12, wherein the working electrode has at least one dimension of less than 50 μ

m.

14. A device according to claim 12, wherein the electroactive substance is in dried form.

9. Use of a membrane comprising one or more layers to confine an electroactive substance within a receptacle following insertion into the receptacle of a liquid sample,

wherein the receptacle comprises a first open part, and is in the form of an electrochemical cell,

wherein the membrane is permeable to the sample, and is located such that it covers the first open part of the receptacle, and

wherein the electroactive substance is contained within the receptacle prior to insertion of the sample.

11. Use according to claim 9, wherein the membrane is impermeable to red blood cells and the sample is plasma or serum.

15. (canceled)