US5198367A
Expired / Lapsed
US
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Homogeneous amperometric immunoassay
Assignee: Bayer Corp
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Filing: 1989-06-09
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Granted: 1993-03-30
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Expires: 2009-06-09
Abstract
Abstract A method is described for measuring the amount of analyte present in a sample containing the analyte using a homogeneous amperometric immunoassay. The analyte is covalently bonded to a suitable carrier molecule, which is also covalently bonded to an electroactive molecule. The electroactive molecule, such as ferrocene carboxylic acid, contains a redox center which is capable of transferring a charge to an electrode. A preferred carrier molecule is bovine serum albumin (BSA), while suitable analytes include digoxin, theophylline and HCG. The immunoassay is conveniently performed by applying a voltage to a set of electrodes.
Inventors
- 👤 Masuo Aizawa
- 👤 Brenda D. Manning
- 👤 Miki Hidaka
- 👤 Laura S. Uretsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:27
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/543; G01N33/54366; G01N33/54373; G01N33/5438; G01N33/536; G01N33/542; Y; Y10; Y10S; Y10S435/00; Y10S435/817; Y10S436/00; Y10S436/806; Y10S436/815; Y10S436/817; Y10S436/818; Y10S530/00; Y10S530/807; Y10S530/81; Y10S530/812
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
144 words
A method for determining the concentration of an analyte present in a sample of biological fluid contained in an electrochemical cell equipped with a set of electrodes, said method comprising the steps of: a) forming an electroactive complex containing an antigenic analyte covalently bonded to a carrier molecule, said carrier molecule also being covalently bonded to an electroactive molecule capable of transferring a charge to an electrode, b) adding the biological fluid, predetermined amounts of the electroactive complex, and an antibody to the analyte to the cell, c) applying a voltage across the electrodes and measuring the current in the fluid at different voltage levels to form a voltage/current relationship for the sample fluid, and d) comparing the voltage/current relationship for the sample fluid with standard voltage/current relationships generated using known amounts of analytes to determine the concentration of analyte present in the sample.
Claim 2
Independent Claim
144 words
A method for determining the concentration of an analyte present in a sample of biological fluid contained in an electrochemical cell equipped with a set of electrodes, said method comprising the steps of: a) forming an electroactive complex containing an antigenic analyte covalently bonded to a carrier molecule, said carrier molecule also being covalently bonded to an electroactive molecule capable of transferring a charge to an electrode, b) adding the biological fluid, predetermined amounts of the electroactive complex, and an antibody to the analyte to the cell, c) applying a voltage across the electrodes and measuring the current in the fluid at different voltage levels to form a voltage/current relationship for the sample fluid, and d) comparing the voltage/current relationship for the sample fluid with standard voltage/current relationships generated using known amounts of analytes to determine the concentration of analyte present in the sample.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein the analyte is selected from the group consisting of theophylline, thryoxine, digoxin and HCG.
Claim 4
Dependent Claim
13 words
The method of claim 1 wherein the carrier molecule is bovine serum albumin.
Claim 5
Dependent Claim
13 words
The method of claim 1 wherein the electroactive molecule is a ferrocene derivative.
Claim 6
Dependent Claim
22 words
The method of claim 4 wherein the ferrocene derivative is selected from the group consisting of ferrocene carboxylic acid and ferrocenylacetic acid.
Claim 7
Dependent Claim
13 words
The method of claim 5 wherein the ferrocene derivative is ferrocene carboxylic acid.
Claim 8
Dependent Claim
31 words
The method of claim 1 wherein the analyte is digoxin, the antibody is a anti-digoxin antibody, the carrier molecule is bovine serum albumin, and the electroactive molecule is ferrocene carboxylic acid.
Claim 9
Dependent Claim
17 words
The method of claim 1 wherein the working and counter electrodes are fabricated from platinum or graphite.
Claim 10
Dependent Claim
16 words
The method of claim 1 wherein the biological fluid is whole blood, plasma, serum or urine.
Claim 11
Dependent Claim
14 words
The method of claim 1 wherein a buffer is added to the fluid sample.
Claim 12
Dependent Claim
28 words
An electroactive complex, comprising at least one antigenic analyte covalently bonded to a carrier molecule, said carrier molecule also being covalently bonded to at least one electroactive molecule.
Claim 13
Dependent Claim
28 words
An electroactive complex, comprising at least one antigenic analyte covalently bonded to a carrier molecule, said carrier molecule also being covalently bonded to at least one electroactive molecule.
Claim 14
Dependent Claim
21 words
The electroactive complex of claim 11 wherein the analyte is selected from the group consisting of theophylline, thyroxine, digoxin, and HCG.
Claim 15
Dependent Claim
14 words
The electroactive complex of claim 11 wherein the carrier molecule is bovine serum albumin.
Claim 16
Dependent Claim
14 words
The electroactive complex of claim 11 wherein the electroactive molecule is ferrocene carboxylic acid.
Claim 17
Dependent Claim
26 words
The electroactive complex of claim 11 wherein the analyte is digoxin, the carrier molecule is bovine serum albumin, and the electroactive molecule is ferrocene caroboxylic acid.
Claim 18
Dependent Claim
30 words
The electroactive complex of claim 15 which is prepared by first covalently binding ferrocene carboxylic acid to bovine serum albumin, and subsequently covalently binding digoxin to the bovine serum albumin.
Claim 19
Dependent Claim
28 words
The electroactive complex of claim 11, wherein the carrier molecule is selected from the group consisting of bovine serum albumin, bovine gamma globulin, ribonuclease, cytochrome C, and insulin.
Claim 20
Dependent Claim
20 words
The electroactive complex of claim 11, wherein the carrier molecule is a molecule having a molecular weight less than 150,000.
Claim 21
Dependent Claim
27 words
The electroactive complex of claim 11, wherein the carrier molecule is selected from a molecule having 1 or more amino groups and/or 1 or more carboxyl groups.
References Cited (Backward Citations)
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