Electrochemical oxygen sensor

• US 5,876,577 A
• Filed: 09/23/1997
• Issued: 03/02/1999
• Est. Priority Date: 09/28/1994
• Status: Expired due to Fees

• Current Assignee: Cranfield Biotechnology, Ltd.
• Original Assignee: Cranfield Biotechnology, Ltd.
• Inventors: Ackland, Martin, McAleer, Jerry
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US08/809,627
• Time in Patent Office: 525 Days
• Field of Search: 204/403, 204/412, 204/415, 204/416, 204/418, 204/431, 204/424, 205/782, 205/782.5, 205/783, 205/783.5, 205/784, 205/785.5, 205/792, 205/792.5, 205/789, 422/79, 422/82.04
• US Class Current: 205/777.5
• CPC Class Codes: G01N 27/404 Cells with anode, cathode and cell electrolyte on the same side of a permeable membrane which separates them from the sample fluid , e.g. Clark-type oxygen sensors

Abstract

An electrochemical oxygen sensor comprises an impermeable substrate and a plurality of conductive layers applied thereto by thick film deposition. At least one conductive layer comprises an electrode and a conductor connected to the electrode. The electrode may have a covering layer of an ion exchange polymer.

Claims

1. An electrochemical oxygen sensor comprising an impermeable substrate and a plurality of conductive layers, at least one conductive layer comprising an electrode and a conductor connected to the electrode, the sensor further comprising a layer of active material overlaying said electrode, wherein the active material comprises an ion exchange polymer and wherein the active layer includes an oxygen reduction catalyst.

2. A sensor as claimed in claim 1, wherein a multiplicity of conductive films are disposed on the substrate and arranged to form a plurality of electrochemical electrodes.

3. A sensor as claimed in claim 2, including a further layer defining an array of receptacles.

4. A sensor as claimed in claim 1, wherein the oxygen reduction catalyst is cobalt (II) tetraaminophenyl porphyrin.

5. A sensor as claimed in claim 1 wherein the conductor is carbon or silver.

6. A sensor as claimed in claim 1, wherein the sensor does not include a gas permeable membrane overlying the electrode.

7. A sensor as claimed in claim 1, including a detector circuit adapted to be connected in use to said conductor, the detector circuit being arranged to detect electrochemical reduction at said electrode at two or more voltages.

8. A method of detecting an amount of dissolved oxygen in a biological fluid, comprising

providing an electrochemical oxygen sensor including an impermeable substrate and a plurality of conductive layers applied thereto by thick film deposition, at least one of said conductive layers including an electrode and a conductor connected to the electrode, the sensor further including a layer of active material overlaying said electrode, wherein the active material comprises an ion exchange polymer and wherein the active layer includes an oxygen reduction catalyst;

and

exposing the biological fluid to the active layer.

9. The method of claim 8, wherein the biological fluid is a foodstuff.