Magnetic immunosensor and method of use
AssigneeAbbott Point of Care Inc.
InventorsCary James Miller, Jinghua Hu
Life of this patent
Estimating the term…
Abstract
The present invention provides apparatus and methods for the rapid determination of analytes in liquid samples by immunoassays incorporating magnetic capture of beads on a sensor capable of being used in the point-of-care diagnostic field.
Claims18
A method of performing a sandwich immunoassay for an analyte in a sample with a magnetic immunosensor, wherein said immunosensor comprises a sensing electrode on a substantially planar chip and a microfabricated magnetic layer on said chip that is positioned substantially proximate to the electrode, wherein the microfabricated magnetic layer comprises:
- high-field permanent magnetic particles dispersed in a thermally, chemically, or photoformably cured immobilization matrix, wherein the immobilization matrix comprises a polyimide, polyvinyl alcohol, or epoxy resin;
- said method comprising:
- (a) mixing magnetically susceptible beads coated with a capture antibody to an analyte with a sample containing the analyte and a signal antibody to form a sandwich on said beads;
- (b) applying the mixture to the immunosensor;
- (c) magnetically localizing and retaining at least a portion of said beads on the electrode;
- (d) washing the unbound sample from the electrode;
- (e) exposing the signal antibody of the sandwich to a signal generating reagent;
- and
- (f) measuring a signal from the reagent at the electrode.
A method of performing a competitive immunoassay for an analyte in a sample with a magnetic immunosensor, wherein said immunosensor comprises a sensing electrode on a substantially planar chip and a microfabricated magnetic layer on said chip that is positioned substantially proximate to the electrode, wherein the microfabricated magnetic layer comprises:
- high-field permanent magnetic particles dispersed in a thermally, chemically, or photoformably cured immobilization matrix, wherein the immobilization matrix comprises a polyimide, polyvinyl alcohol, or epoxy resin;
- said method comprising:
- (a) mixing magnetically susceptible beads coated with a capture antibody with a sample containing a first analyte and a second analyte, wherein the second analyte is labeled, to permit binding on said beads;
- (b) applying the mixture to the immunosensor;
- (c) magnetically localizing and retaining at least a portion of the beads on the electrode;
- (d) washing the unbound sample from the electrode;
- (e) exposing the second analyte to a signal generating reagent;
- and
- (f) measuring a signal from said reagent at the electrode.
Dependencies are inferred from the claim text.