Electrocatalytic Oxidation of Bisphenol A at Oxidized Multi-walled Carbon Nanotube Modified Carbon Paste Electrode

Abstract

Bisphenol A (BPA) was analyzed using carbon paste electrode (CPE) modified with strongly oxidised multi-walled carbon nanotubes (MWCNTs). The surface morphology of the electrode was characterised by FE-SEM and the electrode-electrolyte interface properties were investigated by impedance spectroscopy. On electrocatalytic oxidation of BPA at the modified electrode, the peak current increased with a significant drop in the peak potential at physiological pH. The developed sensor was free from interference of Ascorbic acid, Epinephrine and Uric acid. Quantitative analysis of BPA was performed using amperometry in hydrodynamic condition, which yielded two linear dynamic ranges viz., 3.0×10-7 M to 3.0×10-6 M and 3.0×10-6 M to 1.0×10-4 M with a detection limit of (40.4±1.1) ×10-9 M. The sensor exhibited excellent reproducibility and a good long term stability towards the oxidation of BPA. The electrode was tested for the analysis of BPA in cow’s urine and blood serum by standard addition method and the recoveries obtained were satisfactory.