Fabrication of AuNPs/PHCQE/GPE electrochemical sensor for the determination of isoniazid

In this study, we have developed an electrochemical sensor based conjugated polymer to determine the compound isoniazid. Isoniazid is a drug-active substance widely used in the treatment of tuberculosis. To determine isoniazid electrochemically, 3-(5,8-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-3-9-hexyl-9H-carbazole-3-yl)quinoxalin-2-yl)-9-hexyl-9H-carbazole monomer was first electropolymerized on a graphite pencil electrode and then gold nanoparticles were doped on it. The prepared electrode showed excellent electrocatalytic activity for the oxidation of isoniazid. The electrochemical behavior of isoniazid was examined, and oxidation of isoniazid was determined by the Cyclic Voltammetry technique as a diffusion controlled. The linearity range of isoniazid was calculated 3–100 µM and the detection limit was 0.310 ?M by using differential pulse voltammetry. An electrochemical sensor was successfully applied to the determination of isoniazid in tablet dosage forms. The suggested method provides good recovery, wide linearity range and low detection limit. In addition, interference, repeatability, reproducibility and stability studies were carried out. © 2025 Elsevier B.V.