The electrochemical fabrication of Cu@CeO2-rGO electrode for high-performance electrochemical nitrite sensor

The synthesis of cerium oxide-reduced graphene oxide (CeO2−rGO) and Cu nanoparticles decorated−CeO2−rGO (Cu@CeO2−rGO) nanocomposites based on electrochemical deposition technique and their nitrite sensor application are presented as the first report. CeO2−rGO nanocomposites were prepared via a one-pot and one-step technique on the pencil graphite electrode (PGE) surface. To increase the activity toward nitrite, the CeO2−rGO surface was also decorated with metallic Cu nanoparticles using electrochemical deposition. Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction spectroscopy (XRD), and energy dispersive spectroscopy (EDS) techniques were used for structural characterization. Morphological analysis was performed using the SEM technique. The electrocatalytic properties of fabricated electrodes for nitrite detection were investigated by cyclic voltammetry (CV), amperometry, and electrochemical impedance spectroscopy (EIS). The detection limit, the sensitivity, and the linear range of nitrite on the Cu@CeO2 − rGO electrode were determined as 10.1 nM, 1963.2 μA μM cm−2, and 10–2000 μM, respectively. Moreover, the Cu@CeO2−rGO electrode exhibited high selectivity toward nitrite in the presence of interfering species. The results in the salami sample showed that the Cu@CeO2−rGO electrode could also be used successfully in food analysis.