Electrical sensor
First Claim
1. In an electrochemical sensor for determining the concentration of an analyte in a fluid test sample comprising 1) a non-conductive base which provides a flow path for the fluid test sample and has a counter electrode and a working electrode on its upper surface which are in electrical communication with a detector of electrical current;
- 2) a reaction layer on the upper surface of the working electrode comprising an enzyme and mediator which reacts with the analyte to cause electrons to be transferred between the analyte and the working electrode; and
3) a cover which when mated with the base forms a capillary space with an opening for the introduction of fluid test sample thereto which space contains the flow path for the fluid test sample in which the working and counter electrodes are situated so that the major portion of the counter electrode is located downstream of the opening from the working electrode, with a sub-element of the counter electrode being upstream from the working electrode, so that when electrical communication between only the sub-element of the counter electrode and the working electrode takes place, there is insufficient flow of electrical current through the detector to constitute a valid test upon the application of between the working electrode and the sub-element, the improvement which comprises employing a sub-element of the counter electrode which comprises an electroactive material capable of allowing oxidation to occur at the surface of the working electrode under the applied potential and is present in an amount which is insufficient to maintain the flow of electric current through the detector to constitute a valid determination of analyte concentration.
1 Assignment
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Accused Products
Abstract
Disclosed is an electrochemical sensor for the determination of analytes in body fluids, e.g. glucose in blood. The sensor involves a non-conductive base which provides a flow path for the body fluid with the base having a working and counter electrode on its surface which are in electrical communication with a detector of current. The base and a cover therefore provide a capillary space containing the electrodes into which the body fluid is drawn by capillary action. The counter electrode has a sub-element which contains an electroactive material and is configured in the system (sensor and meter) to provide an error signal when insufficient body fluid is drawn into the capillary.
33 Citations
10 Claims
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1. In an electrochemical sensor for determining the concentration of an analyte in a fluid test sample comprising 1) a non-conductive base which provides a flow path for the fluid test sample and has a counter electrode and a working electrode on its upper surface which are in electrical communication with a detector of electrical current;
- 2) a reaction layer on the upper surface of the working electrode comprising an enzyme and mediator which reacts with the analyte to cause electrons to be transferred between the analyte and the working electrode; and
3) a cover which when mated with the base forms a capillary space with an opening for the introduction of fluid test sample thereto which space contains the flow path for the fluid test sample in which the working and counter electrodes are situated so that the major portion of the counter electrode is located downstream of the opening from the working electrode, with a sub-element of the counter electrode being upstream from the working electrode, so that when electrical communication between only the sub-element of the counter electrode and the working electrode takes place, there is insufficient flow of electrical current through the detector to constitute a valid test upon the application of between the working electrode and the sub-element, the improvement which comprises employing a sub-element of the counter electrode which comprises an electroactive material capable of allowing oxidation to occur at the surface of the working electrode under the applied potential and is present in an amount which is insufficient to maintain the flow of electric current through the detector to constitute a valid determination of analyte concentration. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- 2) a reaction layer on the upper surface of the working electrode comprising an enzyme and mediator which reacts with the analyte to cause electrons to be transferred between the analyte and the working electrode; and
Specification