Novel deliberately sensitive and selective penciclovir voltammetric sensors depending on iron oxide nanoparticles carbon paste electrodes

Abstract

The present study described the construction and electroanalytical characterization of a novel penciclovir (PCV) voltammetric carbon paste sensor fortified with iron oxide nanoparticles (FeONPs/CPEs). Integration of the electrode matrix with iron oxide nanoparticles obviously enhanced the PCV oxidation peak based on its electrocatalytic activity towards the electrooxidation of PCV molecule at the electrode surface. At the optimized pH value, PCV exhibited an irreversible oxidation peak at about 1.03 V following a diffusion–reaction mechanism. Differential pulse voltammograms (DPVs) registered peak current values correlated linearly to the corresponding PCV within the concentration range from 0.09 to 4.656 µg mL−1 PCV with LOD value 0.025 µg mL−1. Based on the electrochemical behavior of PCV at various pH and the scan rate values, and with the aid of molecular orbital calculations, the electrooxidation reaction of PCV molecule undergoes through oxidation of the terminal amino group of the guanine moiety with the participation of one electron and two protons. Based on the reported selectivity and sensitivity of the FeONPs/CPE, PCV can be assayed in pharmaceutical formulations, biological fluids and surface water samples with average recoveries agreeable with the official HPLC-UV method.