Homogeneous amperometric immunoassay
OwnerMasuo Aizawa, Brenda D. Manning +2inventors
InventorsMasuo Aizawa, Brenda D. Manning, Miki Hidaka, Laura S. Uretsky
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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.
Claims19
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.
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.
Dependencies are inferred from the claim text.