Gold nanorods–graphene oxide nanocomposite incorporated carbon nanotube paste modified glassy carbon electrode for voltammetric determination of indomethacin

•This work presents a nanocomposite consisting of gold nanorods and graphene oxide.•An electrode was successfully modified with the prepared nanocomposite.•The salient feature of this electrode is large effective surface area.•The proposed electrode decreased overpotential of indomethacin electrooxidation.

A novel, simple and selective electrochemical method was investigated for the determination of indomethacin in aqueous media (phosphate buffer solution, pH 8.0) on gold nanorods–graphene oxide nanocomposite incorporated carbon nanotube paste modified glassy carbon electrode (GNRs–GO–CNTP/GCE) using square wave voltammetry (SWV). The GNRs–GO–CNTP/GCE displayed high effective surface area, more reactive sites and excellent electrochemical catalytic activity toward the oxidation of indomethacin. The detection limit of 1.7 × 10−2 μM and two linear calibration ranges of 0.2–0.9 and 2.5–91.5 μM were obtained for indomethacin determination at GNRs–GO–CNTP/GCE. The proposed modified electrode was successfully applied for the determination of indomethacin in human blood serum, urine and pharmaceutical samples.