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.