Electrochemical determination of dopamine, acetaminophen and vitamin B2 using glassy carbon electrode modified with poly(O-phenylenediamine)-zirconium(ivIV) oxide-functionalized multi-walled carbon nanotubes

In this thesis, a hybrid composite (PoPD-ZrO2-f-MWCNT) consisting of poly(o￾phenylene diamine) (PoPD), zirconium(IV) oxide (ZrO2), and functionalized multi￾walled carbon nanotubes (f-MWCNT) was prepared. Using this composite modified glassy carbon electrode (GCE), the electrochemical determinations of dopamine (DA), acetaminophen (AAP), and vitamin B2 (B2V) for individual measurements were studied. The structural characterization of the prepared PoPD polymer and the PoPD-ZrO₂, PoPD￾f-MWCNT, and PoPD-ZrO₂-f-MWCNT composites was performed using ATR Fourier transform infrared spectroscopy (FT-IR). The surface morphologies of the prepared materials were examined using field emission scanning electron microscopy (FE-SEM). The electrochemical characterization of bare and modified GCE was performed using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods. Differential pulse voltammetry (DPV) was used for the electrochemical determination of DA, AAP, and B2V. In individual analytical studies, the linear working ranges for DA, AAP, and B2V were determined to be 2–100 μmol L−1 , 4–1000 μmol L−1 , and 0.2–10 μmol L−1 , respectively. Keywords: Acetaminophen, Dopamine, Electrochemical Sensor, Functionalized Multi￾Walled Carbon Nanotubes, Poly(o-Phenylenediamine), Vitamin B2, Zirconium (IV) Oxide