A novel electrochemical biosensor for the detection of ethambutol

A glassy carbon electrode (GCE) has been fabricated with zinc oxide nanoparticles (ZnONPs) and reduced graphene oxide (RGO) immobilized with horseradish peroxidase enzyme (HRP) for the voltammetric determination of ethambutol. Electrochemical behaviour of ethambutol has been studied with cyclic voltammetry and differential pulse voltammetry. The HRP-ZnONPs-RGO-GCE exhibits high electrooxidation of ethambutol in phosphate buffer solution at pH 7.0 and the electrochemical signal is significantly enhanced. In addition, the proposed biosensor has been characterized by transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. The HRP-ZnONPs-RGO-GCE shows an oxidation peak at -0.2 V with CV. Under the optimized conditions, the DPV technique gave good limit of detection and limit of quantification values of 0.0214 mu M and 0.6713 mu M respectively. The HRP-ZnONPs-RGO-GCE shows excellent background current stability and gives reliable performance with pharmaceutical samples in the terms of sensitivity, reproducibility and repeatability.