A Cerium Hexacyanoferrate (III) Nanoparticle-modified Carbon Paste Electrode: Voltammetric Characterization and Behavior in the Presence of Dopamine

Abstract

This study describes a fast and simple methodology for the preparation of Cerium (III) Hexacyanoferrate (II) (CeHCF) nanoparticles (NPs). The NPs were characterized by fourier transform infrared (FTIR), x-ray diffraction (XRD), scanning electron microscopy (SEM) and cyclic voltammetry (CV). The CeHCF cyclic voltammogram indicate a well-defined redox pair assigned as Fe2+/Fe3+ in the presence of cerium (III), with a formal potential of Eθ′=0.29 V (v=100 mV s−1, KNO3; 1.0 mol/L, pH 7.0). The carbon paste electrode modified with CeHCF (CeHCF-CPE) was applied to the catalytic electrooxidation of dopamine applying Differential Pulse Voltammetry (DPV). DPV showed linear response at two concentration ranges, from 9.0×10−7 to 8.0×10−6 and 9.0×10−6 to 1.0×10−4 mol/L, with an LOD of 1.9×10−7 and 1.0×10−5 mol/L, respectively. The CeHCF-CPE exhibited selectivity against substances commonly found in biological samples, with redox potentials close to that of dopamine, such as urea and ascorbic acid (AA). Subsequently the CeHCF-CPE was successfully applied to the detection of dopamine in simulated urine samples, with recovery percentages ranging between 99 and 103%.