Patent ID: 8691073

Claim:
A method of quantifying an analyte in a sample, comprising: contacting the sample with an electrochemical sensor strip; the electrochemical sensor strip before being contacted with the sample comprising a working electrode and a counter electrode, where the working and the counter electrodes include compositions that are different from each other, the composition of the working electrode includes a mediator and an oxidoreductase enzyme capable of facilitating a redox reaction of the analyte that is specific for the analyte, and the composition of the counter electrode includes a first soluble redox species having a standard reduction potential of at least +0.24 volts in relation to a standard hydrogen electrode; applying an electrical potential between the working and the counter electrodes; stopping the electrical potential between the working and the counter electrodes; reapplying the electrical potential between the working and the counter electrodes; measuring a current passing through the working and the counter electrodes and the sample, where when the electrical potential is reapplied between the working and the counter electrodes, a redox reaction at the working electrode is opposite a redox reaction at the counter electrode, the mediator regenerates an oxidation state of the oxidoreductase enzyme after the redox reaction of the analyte, the mediator undergoes the same redox reaction as the analyte at the working electrode, the mediator undergoes the opposite redox reaction as the analyte when regenerating the oxidation state of the oxidoreductase enzyme, the first soluble redox species undergoes the opposite redox reaction of the analyte, and there is no detectable migration to the working electrode of reduced first soluble redox species produced at the counter electrode; and correlating the current to a concentration of the analyte, where the correlation between the current and the concentration of the analyte is substantially linear from an analyte concentration of about 50 mg/dL to about 400 mg/dL.