Selective Detection of Glucose by Linear Sweep Voltammetry Using a Copper-Polyaniline Modified Glassy Carbon Electrode

Cu-doped polyaniline (Cu-PA) was prepared by chemical oxidation aniline in the presence of Cu ions. By cyclic voltammetry (CV), the electrochemical behavior of glassy carbon electrode modified with Cu-PA was studied in NaOH solution. Since the hydrolysis of glucose occurs in an alkaline solution and the redox peak of Cu-PA depends on the concentration of OH- concentration, here, a new and cost-effective strategy for the non-enzymatic determination of glucose was proposed based on the inhibitory effect of glucose on the electrical activity of the Cu-PA composite. The cathodic current decreased directly after the addition of glucose and demonstrated that the Cu-PA was sensitive to glucose in an alkaline medium. Using linear sweep voltammetry and under optimal condition, the sensor exhibited a linear calibration graph in the concentration range of 0.11-1.66 mM with a limit of detection (LOD) of 0.044 mM (S/N = 3). In addition, the sensor showed desirably accurate selectivity for detecting and recovering glucose in humans serum samples, good reproducibility, and good stability.