Developing an electrochemical sensor based on a carbon paste electrode modified with ZnO nanoparticles synthesized by microwave for determination of chlorpheniramine maleate

Zinc oxide (ZnO) nanoparticles with an average size of 60 nm have been successfully prepared by microwave irradiation. Carbon paste electrode (CPE) was modified with ZnO nanoparticles and used for the electrochemical oxidation of chlorpheniramine maleate (CPM). Cyclic voltammetry (CV) study of the modified electrode indicated that the oxidation potential shifted towards a lower potential by approximately 106 mV and the peak current was enhanced by 2 fold in comparison to the bare CPE (ZnO/CPE-CV). The electrochemical behaviour was further described by characterization studies of scan rate, pH and concentration of CPM. Under the optimal conditions, the peak current was proportional to CPM concentration in the range of 8.0 ×10-7 to 1.0 × 10-3 mol L-1 with a detection limit of 5.0 × 10-7 mol L-1 by differential pulse voltammetry (DPV). The peak current of CPM is linear in the concentration range of 0.8 - 1000 µM (R2=0.998). The ZnO/CPE has good reproducibility and high stability for the determination of CPM using this electrode. The proposed method was successfully applied to the determination of CPM in pharmaceutical samples. In addition, the important analytical parameters were compared with other methods which show that ZnO/CPE-CV procedure is comparable to recently reported methods.