Based on the modification of carbon paste electrode with NiCo2O4 nanoplates and 1-hexyl-3-methylimidazolium tetrafluoroborate, a new electrochemical sensing platform for the sensing of favipiravir (a drug with potential therapeutic efficacy in treating COVID-19 patients) in the presence of acetaminophen was prepared. For determining the electrochemical behavior of favipiravir, cyclic voltammetry, differential pulse voltammetry, and chronoamperometry have been utilized. When compared to the unmodified carbon paste electrode, the results of the cyclic voltammetry showed that the proposed NiCo2O4 nanoplates/1-hexyl-3-methylimidazolium tetrafluoroborate/carbon paste electrode had excellent catalytic activity for the oxidation of the favipiravir in phosphate buffer solution (pH = 7.0). This was due to the synergistic influence of 1-hexyl-3-methylimidazolium tetrafluoroborate (ionic liquid) and NiCo2O4 nanoplates. In the optimized conditions of favipiravir measurement, NiCo2O4 nanoplates/1-hexyl-3-methylimidazolium tetrafluoroborate/carbon paste electrode had several benefits, such as a wide dynamic linear between 0.004 and 115.0 µM, a high sensitivity of 0.1672 µA/µM, and a small limit of detection of 1.0 nM. Furthermore, the NiCo2O4 nanoplates/1-hexyl-3-methylimidazolium tetrafluoroborate/carbon paste electrode sensor presented a good capability to investigate the favipiravir and acetaminophen levels in real samples with satisfactory recoveries.
Keywords: 1-hexyl-3-methylimidazolium tetrafluoroborate; NiCo2O4 nanoplates; acetaminophen; carbon paste electrode; favipiravir.