Electrochemical Sensor for Ethylene Glycol using Reduced Graphene Oxide/AuNp/Ni(OH)₂ Modified Glassy Carbon Electrode

Abstract

An electrochemical sensor based on a modified glassy carbon electrode (GCE) with reduced graphene oxide and Ni-Au nanoparticles (Ni(OH)₂/AuNp/rGO/GCE) was developed for the determination of ethylene glycol. The graphene oxide was reduced electrochemically at the electrode surface by chronoamperometry, the gold nanoparticles were deposited by chronopotentiometry while the nickel hydroxide nanoparticles were deposited by cyclic voltammetry. The characterization of graphene oxide was performed by Raman spectroscopy, X-ray diffraction (XRD) and transmission-mode scanning electron microscopy (TSEM), while the modified electrodes were characterized by scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS) analysis. The determination of ethylene glycol was performed by cyclic voltammetry due to the regeneration of the active sites, preventing loss of the sensor signal. The modified GCE with rGO and Ni(OH)₂/AuNp showed a good performance obtaining a linear range of 0.24 to 1.4 mmol L^-1 with a correlation coefficient of 0.9903, limits of detection and quantification (49 and 162 µmol L^-1, respectively) and high stability with 500 continuous analysis cycles.

Keywords:
Ethylene glycol; nickel nanoparticles; gold nanoparticles; reduced graphene oxide; cyclic voltammetry