Enzymatic electrochemical method for the quantification of analytes in biological fluid samples

An enzymatic electrochemical method for quantification of an analyte in a biological fluid sample, the method comprising:

• introducing the biological fluid sample in an electrochemical system formed by a first biosensor strip and a second biosensor strip, the first biosensor strip including a first working electrode modified with an enzyme and an electrochemical mediator, a first reference electrode and a first auxiliary electrode, the second biosensor strip including a second working electrode, a second reference electrode and a second auxiliary electrode, the second working electrode being modified with the enzyme, the electrochemical mediator and a cofactor;
• applying a constant potential to the first and second working electrodes, the first and second reference electrodes and the first and second auxiliary electrodes during a set period of time;
• obtaining current intensity data by measuring a current intensity produced by a re-oxidation of the cofactor on the second working electrode after the cofactor being initially reduced due to a reaction between the enzyme and the analyte on each of the first and second biosensor strips, and subtracting a response obtained in each of the first working electrode, first reference electrode and first auxiliary electrode from a response respectively obtained in each of the second working electrode, second reference electrode and second auxiliary electrode, the re-oxidation of the cofactor being facilitated by the electrochemical mediator;
• translating the current intensity data by use of a calibration curve obtained from samples of a synthetic biological fluid comprising different concentrations of the analyte to be determined.