Membrane based electrochemical test device and related methods

• US 6,001,239 A
• Filed: 09/30/1998
• Issued: 12/14/1999
• Est. Priority Date: 09/30/1998
• Status: Expired due to Fees

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Mercury Diagnostics, Inc.
• Inventors: Roe, Jeffrey N., Douglas, Joel S., Priest, John H., Hasker, David A.
• Primary Examiner(s): Tung, T.
• Assistant Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US09/164,405
• Time in Patent Office: 440 Days
• Field of Search: 204/415, 204/403, 205/777.5, 205/778, 205/793, 427/2.1, 427/2.11, 427/2.13
• US Class Current: 205/778
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: C12Q 1/26 involving oxidoreductase
• 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: G01N 33/54386 Analytical elements

Abstract

An electrochemical test device is provided for determining the presence or concentration of an analyte in an aqueous fluid sample. The electrochemical test device includes a working electrode and a counter electrode made of an amorphous semiconductor material. The working electrode is overlaid with a reagent capable of reacting with an analyte to produce a measurable change in potential which can be correlated to the concentration of the analyte in the fluid sample. The test device optionally contains a reference electrode made of an amorphous semiconductor material having a reference material on the reference electrode.

Claims

1. An electrochemical test device for determining the presence or concentration of an analyte in an aqueous fluid sample, said electrochemical test device comprising:

(a) a non-conductive membrane having a first skin and a second skin and a matrix therebetween;

(b) a working electrode comprising an amorphous semiconductor material affixed to the non-conductive membrane first skin, said working electrode having an first electrode area, a first lead and a first contact pad;

(c) an opposing electrode comprising an amorphous semiconductor material affixed to the non-conductive membrane second skin, said opposing electrode having an second electrode area, a second lead and a second contact pad; and

(d) a reagent capable of reacting with the analyte to produce a measurable change in potential which can be correlated to the concentration of the analyte in the fluid sample, said reagent imbibed in the membrane matrix between the working electrode and opposing electrode.

2. The electrochemical test device of claim 1 wherein said device further comprises a reference electrode comprising an amorphous, semiconductor material affixed to the non-conductive membrane second skin, said reference electrode having a third electrode area, a third lead, and a third contact pad, and wherein at least a portion of the third electrode area is overlaid with a reference material.

3. The electrochemical test device of claim 2 wherein said reference material is silver/silver chloride.

4. The electrochemical test device of claim 1 wherein the non conductive membrane is selected from polysulphone, polyethersulphone, or nylon and is cased with a tight pore skin on each side and a relatively isotropic matrix between the skin surfaces.

5. The electrochemical test device of claim 1 wherein the amorphous semiconductor material is amorphous silicon oxide.

6. The electrochemical test device of claim 1 wherein the reagent comprises a glucose oxidase and a redox mediator.

7. A method for determining the presence or concentration of an analyte in an aqueous fluid sample, said method comprising:

(a) providing an electrochemical test device co uprising;

(i) a non-conductive double skinned membrane;

(ii) a working electrode comprising an amorphous semiconductor material affixed to the non-conductive membrane'"'"'s first skin surface, said working electrode having an first electrode area, a first lead and a first contact pad;

(iii) a counter electrode comprising an amorphous semiconductor material affixed to the non-conductive membrane'"'"'s second skin surface, said counter electrode having a second electrode area, a second lead, and a second contact pad; and

(iv) a reagent capable of reacting with the analyte to produce a measurable change in potential which can be correlated to the presence or concentration of the analyte in the fluid sample, said reagent imbibed into the membrane between the working and opposing;

(b) inserting the electrochemical test device into a meter device;

(c) applying a sample of an aqueous fluid to the first electrode area of the working electrode;

(d) reading the meter device to determine the presence or concentration of the analyte in the fluid sample.

8. The method of claim 7 wherein the electrochemical test device further comprises a reference electrode comprising an amorphous semiconductor material affixed to the non-conductive membrane'"'"'s second skin surface, said reference electrode having a third electrode area, a third lead, and a third contact pad, and wherein at least a portion of the third electrode area is overlaid with a reference material.

9. The electrochemical test device of claim 7 wherein the non conductive membrane is selected from polysulphone, polyethersulphone, or nylon and is cased with a tight pore skin on each side and a relatively isotropic matrix between each skin surface.

10. The method of claim 7 wherein the reagent comprises an enzyme and a redox mediator.

11. A process for preparing an electrochemical test device suitable for determining the presence or concentration of an analyte in an aqueous fluid sample, said process comprising the steps of:

(a) providing a non-conductive double skinned membrane;

(b) depositing an amorphous semiconductor material on the first skin surface to form a conductive layer which forms a working electrode comprising a first electrode having a first electrode area, a first lead and a first contact pad

(c) depositing an amorphous semiconductor material on the second skin surface to form a conductive layer;

which forms an opposing electrode comprising a second electrode having a second electrode area, a second lead and a second contact pad

(d) applying a reagent to imbibe the membrane through the first electrode area of the working electrode, said reagent being capable of reacting with an analyte in an aqueous fluid sample to produce a measurable change in potential which can be correlated to the concentration of the analyte in the fluid sample.

12. The process of claim 11 wherein step (c) further comprises forming a reference electrode on the second skin surface comprising a third electrode having a third electrode area, a third lead and a third contact pad.

13. The electrochemical test device of claim 11 wherein the non conductive membrane is selected from polysulphone, polyethersulphone, or nylon and is cased with a tight pore skin on each side and a relatively isotropic matrix between each skin surface.

14. The process of claim 11 wherein the reagent comprises a glucose oxidase and a redox mediator.