Apparatus and method for measuring concentration of an analyte in bio-samples

An apparatus for measuring a concentration of an analyte in a bio-sample, the apparatus comprising:

• a connector to which a sample cell in which an oxidation/reduction enzyme capable of catalyzing an oxidation/reduction reaction of the analyte and an electron transfer mediator are fixed and a working electrode and a counter electrode are provided is for being inserted;
• a digital-to-analog converter circuit configured to obtain a first induced current by applying a constant DC voltage to start the oxidation/reduction reaction of the analyte and proceed with an electron transfer reaction, and configured to obtain a second induced current by applying a Λ-step ladder-type perturbation potential for fluctuating a potential of the sample cell after applying the constant DC voltage, wherein the digital-to-analog converter circuit is configured obtain the second induced current subsequent to obtaining the first induced current;
• and
• a microcontroller configured to control the digital-to-analog converter circuit and directly obtain a concentration value of the analyte from a calibration equation using the Λ-step ladder-type perturbation potential,
• wherein the calibration equation is formed of at least one feature function so as to minimize an effect of at least one hindering material in the bio-sample,
• wherein the at least one feature function comprises a function using the first induced current obtained from the constant DC voltage and a function using the second induced current obtained from the Λ-step ladder-type perturbation potential,
• wherein the Λ-step ladder-type perturbation potential is characterized by a height (Vstep) of each step, an application time (tstep) for each step, a difference (Vcenter) between a middle voltage and a constant voltage in an entire range of variations, a difference (Vpeak) between a middle voltage and a peak voltage, and a time difference (tcycle) between a peak voltage of an entire step ladder-type wave and a peak voltage of an adjacent next step ladder-type wave,
• wherein the digital-to-analog converter circuit, linked with the microcontroller, is configured to apply the constant DC voltage and the Λ-step ladder-type perturbation potential to the working electrode, and
• wherein the apparatus is configured to select a characteristic point, having different linearity with respect to the analyte and the hindering material, from the first or second induced current, configured to form a feature of the characteristic point, and configured to form the calibration equation of the feature.