Graphite-based sensor amended with fumed silica for electrodetection of azithromycin

Abstract

Azithromycin (AM) detection has become of great interest as being one of the prescribed medicines in the medication protocol in Egypt for the recent coronavirus disease 2019 pandemic. Herein, a carbon paste electrode was simply amended with fumed silica for determining AM. The characterization of the new material was done by different techniques, including scanning electron microscopy, transmission electron microscopy, and electrochemical impedance spectroscopy. The newly modified fumed silica carbon paste electrode exhibited a highly sensitive response toward the oxidation of 1.0 mmol/L AM in phosphate buffer solution (PBS) for a pH range of 5.0–10.0. The effect of varying AM concentrations was studied in PBS, pH 7.4, with a detection limit of 11 μmol/L and a quantification limit of 37 μmol/L. Eventually, the recently amended electrode attained reasonable sensitivity and constancy for AM detection in actual trials, such as blood plasma and pharmaceutical drugs.