Electrocatalytic oxidation of the antiviral drug acyclovir on a copper nanoparticles-modified carbon paste electrode

The electrocatalytic oxidation of acyclovir (Zovirax) on two different copper-based electrodes: copper microparticles- and copper nanoparticles-modified carbon paste electrodes (denoted as micro-CPE and nano-CPE, respectively) was voltammetrically investigated. In the voltammogram recorded using micro-CPE, a single anodic oxidation peak appeared, while nano-CPE resulted in two overlapped anodic peaks. The anodic currents were related to the electrocatalytic oxidation of acyclovir via the electrogenerated active species of Cu(III) with an EC’ mechanism. Acyclovir was oxidized with higher rates at low potentials on nano-CPE compared to micro-CPE. This was related to the nanosize effect of copper nanoparticles. The constants of the electrocatalytic oxidation process and the diffusion coefficient of acyclovir were reported. A sensitive and time-saving determination procedure was developed for the analysis of acyclovir and the corresponding analytical parameters were reported. The proposed amperometric method was applied to the analysis of commercial pharmaceutical products (tablets and topical cream) and the results were in good agreement with the declared values.