Patent ID: 8771500

Claim:
A method comprising: performing periodic biasing amperometry on a sensor, the sensor comprising: a reference electrode; a counter electrode; a working electrode; the working electrode being disposed in the vicinity of the reference and counter electrode; an electrically conducting membrane; the electrically conducting membrane being in operative communication with the working electrode; an enzyme layer; the enzyme layer being in operative communication with the working electrode; a semi-permeable membrane; the semi-permeable membrane being in operative communication with the working electrode introducing a sample comprising an analyte being measured to the sensor; the periodic biasing amperometry comprising: determining a normal operating state for the sensor by biasing the working electrode for the same duration of time at intervals (t wait ) having the same periods of time at a number of testing potentials; repeating the periodic biasing for all the testing potentials; continuing the periodic biasing until a steady state is attained for all the testing potentials; conducting an internal calibration of the sensor after the analyte being measured has reached a steady state; the internal calibration comprising a time interval (t cal ) where the periodic biasing is not applied; where t cal =n×t wait , where n is a number of about 2 to about 10; measuring a periodic biasing amperometric signal difference immediately before and immediately after the time interval (t cal ): comparing the differential with a calibration chart to obtain sensitivity factors; and applying the sensitivity factors to the sensor to correct against drifts; and performing biasing amperometry at a time interval of t eq to ensure that the sensor returns to its normal operating state; where t eq is less than t wait .