Binary transition metal oxide based electrochemical sensor for the evaluation of chlorogenic acid in real-time samples

Abstract

A composite based on the binary transition metal oxide synthesized via the one-step hydrothermal method, it is modified over the surface of the glassy carbon electrode (GCE) towards the electrochemical determination of chlorogenic acid (CGA). Binary transition metal oxide-based modified electrodes result in activating the elec-trochemical properties due to unique morphologies with greater active surface area. Herein, we developed a composite of Iron Oxide/Zinc Oxide (Fe3O4/ZnO) binary metal oxide-based fabricated modified (GCE) electrode towards the determination of chlorogenic acid (CGA). As-synthesized Fe3O4/ZnO composite features like structural, composition, and morphologies were characterized via XRD, FT-IR, XPS, FESEM & HR-TEM. In this regard, electrochemical measurements by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and linear sweep voltammetry (LSV) techniques were evolved. Further, Fe3O4/ZnO/GCE tends to exhibit a superior kinetic transfer rate with a better electron transfer rate of 507 omega. Alongside, electrochemical evaluation of CGA under Fe3O4/ZnO/GCE exhibits a wider linear range of 0.05-1291 mu M in LSV, with a nanomolar detection of (CGA) 5.1 nM also recorded with a sensitivity of the sensor found to be 0.05 mu A mu M-1 cm-2. The proposed Fe3O4/ZnO/GCE sensor shows exceptional selectivity on interference studies with practical feasibility features of repeatability, reproducibility, and storage stability, also having 99% recovery for the real-time samples in coffee and tea powder.