Methods and apparatus using galvanic immunoelectrodes

• US 4,927,502 A
• Filed: 01/31/1989
• Issued: 05/22/1990
• Est. Priority Date: 01/31/1989
• Status: Expired due to Term

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Smyth, Malcolm R., O'Kennedy, Richard, Reading, Christopher L.
• Primary Examiner(s): Kaplan, G. L.
• Application Number:
  US07/304,739
• Time in Patent Office: 476 Days
• Field of Search: 435/7, 435/291, 204/403, 204/1 T, 128/635
• US Class Current: 205/777.5
• CPC Class Codes: G01N 33/5438 Electrodes
• CPC Class Codes: Y10S 436/806 Electrical property or magnetic property

Abstract

Methods and apparatus for detecting immunochemical reactions and levels of antigens and antibodies in serum. A selected immunochemical reactant is bound to the surface of a first electrode. A second electrode is provided such that the electrodes generate a galvanic current when electrically interconnected and immersed in conductive aqueous solution. The electrodes are electrically interconnected and immersed into a conductive aqueous solution containing the complementary immunochemical reactant to the bound immunochemical reactant. The galvanic current generated by the immersed electrodes is measured as a function of time. The level of the complementary immunochemical reactant in the solution is calculated by comparing the measured current with a standard current.

Claims

1. A method for measuring the level of a complementary immunochemical reactant in a conductive aqueous solution, comprising the steps of:

providing a first electrode and a second electrode, the electrodes having surfaces and generating a galvanic current when electrically interconnected and immersed in a conductive aqueous solution;

binding a selected immunochemical reactant to the surface of the first electrode;

electrically interconnecting the first and second electrodes;

immersing the electrodes in a conductive aqueous solution containing the complementary immunochemical reactant to the bound immunochemical reactant;

measuring the galvanic current generated by the immersed electrodes as a function of time;

calculating the level of the complementary immunochemical reactant in the solution by comparing the measured current with a standard current;

wherein the standard current substantially represents the galvanic current as a function of time generated by the electrodes when immersed in a standard solution, the standard solution being a solution having similar conductivity to the conductive aqueous solution and containing no complementary immunochemical reactant.

2. The method of claim 1, wherein the bound immunochemical reactant is an antibody, and the complementary immunochemical reactant is an antigen.

3. The method of claim 1, wherein the bound immunochemical reactant is an antigen, and the complementary immunochemical reactant is an antibody.

4. The method of claim 1, wherein the conductive aqueous solution is a serum.

5. The method of claim 1, wherein the conductive aqueous solution is plasma.

6. The method of claim 1, wherein the conductive aqueous solution is whole blood.

7. The method of claim 1, wherein the conductive aqueous solution is urine.

8. The method of claim 1, wherein the first electrode is an anode.

9. The method of claim 1, wherein the first electrode is a cathode.

10. The method of claim 1, wherein the first electrode comprises gold, cobalt, iron, silver, copper or solder.

11. A device for measuring the level of a complementary immunochemical reactant in a conductive aqueous solution, comprising:

a first electrode having a surface and having a selected immunochemical reactant bound to its surface and a second electrode, the electrodes generating a galvanic current when electrically interconnected and immersed in a conductive aqueous solution;

an electrical interconnection between the first and second electrodes;

means for measuring the galvanic current generated by the first and second electrodes as a function of time when immersed in a conductive aqueous solution;

means for comparing the measured galvanic current with a standard current and calculating the level of the complementary immunochemical reactant;

wherein the standard current substantially represents the galvanic current as a function of time generated by the electrodes when immersed in a standard solution, the standard solution being a solution having similar conductivity to the conductive aqueous solution and containing no complementary immunochemical reactant.

12. The device of claim 11, further comprising means for displaying the level of complementary immunochemical reactant in the conductive aqueous solution.

13. The device of claim 11, wherein the bound immunochemical reactant is an antibody.

14. The device of claim 11, wherein the bound immunochemical reactant is an antigen.

15. The device of claim 11, further comprising a catheter housing the electrodes.

16. The device of claim 11, wherein the first metallic electrode comprises gold, cobalt, iron, silver, copper or solder.

17. The device of claim 11, wherein the first electrode is an anode.

18. The device of claim 11, wherein the first electrode is a cathode.

19. The device of claim 11, wherein the means for measuring the galvanic current as a function of time is a coulometer.

20. A device for measuring the level of a plurality of complementary immunochemical reactants in a conductive aqueous solution, comprising:

a plurality of first electrodes, each first electrode having a surface and different immunochemical reactant bound to its surface, and a common electrode, each first electrode generating a galvanic current when electrically interconnected with the common electrode and immersed in a conductive aqueous solution;

an electrical interconnection between each first electrode and the common electrode;

means for measuring the galvanic current generated by each first electrode and common electrode as a function of time when immersed in a conductive aqueous solution;

means for comparing each measured galvanic current with a standard current and calculating the level of each complementary immunochemical reactant to each bound immunochemical reactant;

wherein the standard current substantially represents the galvanic current as a function of time generated by the electrodes when immersed in a standard solution, the standard solution being a solution having similar conductivity to the conductive aqueous solution and containing no complementary immunochemical reactants.

21. The device of claim 20, wherein each bound immunochemical reactant is a different antibody.

22. The device of claim 20, wherein each bound immunochemical reactant is a different antigen.