Biological detection process using polymer-coated electrodes

• US 4,517,291 A
• Filed: 08/15/1983
• Issued: 05/14/1985
• Est. Priority Date: 08/15/1983
• Status: Expired due to Term

• Current Assignee: Dade Behring, Inc. (Siemens AG)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Seago, James L.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Chapman, Terryence
• Application Number:
  US06/523,168
• Time in Patent Office: 638 Days
• Field of Search: 204/1 E, 204/403, 435/418, 435/4, 435/11, 435/14, 435/25, 435/26, 435/288, 435/291, 435/817, 436/63, 436/150, 436/95
• US Class Current: 205/778
• CPC Class Codes: C12M 41/36 of biomass, e.g. colony counters or by turbidity measurements electrooptical investigation of individual particles G01N15/14, flow cytometers G01N15/1404
• CPC Class Codes: C12Q 1/005 involving specific analytes or enzymes including groups of enzymes, e.g. oxydases; C12Q1/004 takes precedence
• CPC Class Codes: Y10S 435/817 Enzyme or microbe electrode
• CPC Class Codes: Y10T 436/144444 Glucose

Abstract

A method is described for the amperometric determination of the concentration in a biological sample of a constituent which is a substrate for an oxidase enzyme by (1) catalyzing the substrate with the enzyme, thereby consuming O₂ and producing H₂ O₂ and (2) measuring the O₂ consumption or H₂ O₂ production by means of an inert metal indicator electrode intimately coated with a thin film of a perfluorosulfonic acid polymer.

A reaction chamber is described which provides means for contacting the sample with the enzyme and means for making amperometric measurements utilizing inert metal indicator electrodes coated with a thin film of a perfluorosulfonic acid polymer.

Claims

1. In a method for the amperometric determination of the concentration of a constituent of interest in a biological sample, said method comprising:

(1) contacting said constituent with an oxidase enzyme for which the constituent is a substrate, thereby producing a change in the concentration of an electroactive substance in said sample;

(2) contacting said sample containing said electroactive substance with an inert metal indicator electrode;

(3) measuring the current flow between said indicator electrode and a counter electrode at a preselected potential difference between said electrodes; and

(4) relating the current to the concentration of the substrate initially present in the biological sample;

the improvement comprising;

using as the inert metal indicator electrode a noble metal having intimately coated thereon a thin film of perfluorosulfonic acid polymer.

2. The method of claim 1 wherein the noble metal is selected from the group consisting of platinum and gold.

3. The method of claim 2 wherein the noble metal is platinum.

4. The method of claim 1 wherein the constituent of interest is glucose and the oxidase enzyme is glucose oxidase.

5. The method of claim 4 wherein the noble metal is platinum.

6. The method of claim 1 wherein the perfluorosulfonic acid polymer has an equivalent weight of at least about 900.

7. The method of claim 6 wherein the perfluorosulfonic acid polymer has an equivalent weight of about 1100.

8. The method of claim 1 wherein the thin film is less than about 0.005 inch.

9. The method of claim 1 wherein the thin film is about 0.001 inch.