Electropolymerized poly(Congo red) on graphene oxide: a novel platform for electrochemical sensing of acyclovir

Abstract

In this work, a composite electrode was prepared by the electropolymerization of Congo red on a graphene oxide glassy carbon electrode (PCR/GO/GCE). The modified electrode surface was characterized by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The electrochemical behavior of acyclovir (ACV), a widely used antiviral drug, was investigated using CV and DPV techniques in pH 5.1 Britton–Robinson (BR) buffer. Selective and stable responses were exhibited by the developed electrode, which provided a 45-fold higher current value compared to the bare GCE. DPV studies revealed linear ranges between 0.01 μmol L⁻¹ and 1.3 μmol L⁻¹ and between 2.2 and 18 μmol L⁻¹, with a detection limit of 3.4 nmol L⁻¹. The practical applicability of PCR/GO/GCE was demonstrated in pharmaceutical real sample analysis with high accuracy.