Electrochemically deposited CeO₂ on cobalt phthalocyanine-multiwalled carbon nanotube film electrode for determination of rutin

The electrochemical behavior of rutin on cerium oxide/cobalt phthalocyanine-multiwalled carbon nanotube-modified glassy carbon electrode (CeO2/MWCNT-CoPc/GCE) film was examined using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and amperometry in a Britton-Robinson buffer at pH 3.0. The physical and chemical characterization of the modified electrode was carried out with scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and electrochemical impedance spectroscopy (EIS). The DPV results showed that the developed CeO2/MWCNT-CoPc/GCE demonstrated a linear concentration range between 1.0 x 10(-7) mol L-1 and 2.8 x 10(-5) mol L-1 with a limit of detection of 0.12 mu mol L-1 (S/N = 3). In addition, amperometric measurements had higher sensitivity and revealed two distinct ranges of linear concentration. While the first linear range extends from 3.5 nmol L-1 to 0.17 mu mol L-1, the second linear range was 0.4 mu mol L-1 to 40.1 mu mol L-1. The equations were obtained as i(p) (mu A) = 73.659 x C-Rutin (mu mol L-1) + 2.0432 and i(p) (mu A) = 3.4788 x C-Rutin (mu mol L-1) + 17.928, respectively. From the first linear range curve, LOD was found as 1.3 nmol L-1 (S/N = 3). The CeO2/MWCNT-CoPc/GCE presented satisfactory results for reproducibility, stability, and selectivity. This technique was able to quantify rutin in tablet forms with complete accuracy and precision.