CuFe2O4/reduced graphene oxide nanocomposite decorated with gold nanoparticles as a new electrochemical sensor material for ʟ-cysteine detection

Abstract

A new electrochemical sensor based on glassy carbon electrode modified by CuFe2O4/reduced graphene oxide nanocomposite decorated with gold nanoparticles was developed for the electrochemical detection of ʟ-cysteine. In this study, CuFe2O4/rGO–Au nanocomposite was prepared and characterized by X-ray diffraction, Fourier Transform Infrared and Scanning Electron Microscopy. Electrochemical characterizations of the bare and modified glassy carbon electrodes were carried out via cyclic voltammetry and electrochemical impedance spectroscopy. Also, the modification of glassy carbon electrodes increased the surface area. The CuFe2O4/rGO–Au demonstrated a very efficient electrocatalytic activity for the oxidation of ʟ-cysteine in 0.1 M phosphate buffer (pH = 6.5) and a high sensitivity of 100.01 μA mM−1 cm−2 was obtained. In addition, the electrocatalytic current enhanced linearly with the ʟ-cysteine concentration in the range of 0.05–0.2 mM and with the detection limit of 0.383 μM. All these results indicate that the CuFe2O4/rGO–Au nanocomposite is a novel electrocatalyst for improving of highly sensitive ʟ-cysteine electrochemical sensor.