Patent ID: 6344333
Filing Date: 2002-02-05
Classification: C12Q,G01N,Y10S

Abstract:
An apparatus for immuno-determination of a target analyte in an analyte sample, wherein said target analyte is selected from the group consisting of an antigen, an antibody and a hapten, and wherein said apparatus comprises a sensing device comprising:(i) a single potentiometric working electrode at least one surface of which is located within a housing member, wherein said electrode is connected to a potentiometric measuring circuit and said electrode has the ability to provide an electron to an enzyme label which delivers the electron to a first substrate for the enzyme label, and said electrode has affixed to at least one of its surfaces a binder for at least a labeled detection compound which is labeled with an electrocatalytic enzyme; (ii) a housing member comprising at least one surface that is permeable to an analyte and impermeable to the labeled detection compound, wherein the detection compound is a member selected from the group consisting of (a) a binder for the analyte when the binder on the electrode is the analyte and (b) the analyte when the binder on the electrode is a binder for the analyte, and wherein the detection compound is labeled with an electrocatalytic enzyme or tag; and (iii) an internal medium located within the housing member and wherein said medium is a member selected from a gel and a liquid and wherein said medium contains a pre-determined amount of a labeled detection compound; and (iv) an electrochemical reference electrode connected to a potentiometric measuring circuit, wherein either said internal medium or the analyte sample comprises a second substrate for the enzyme label and the analyte binds to one of either the binder on said working electrode or the detection compound.