Developing an electrochemical sensor based on a carbon paste electrode modified with nano-composite of reduced...

In this paper, a highly sensitive voltammetric sensor based on a carbon paste electrode with CuFe₂O₄ nanoparticle (RGO/CuFe₂O₄/CPE) was designed for determination of hydrogen peroxide (H₂O₂). The electrocatalytic reduction of H₂O₂ was examined using various techniques such as cyclic voltammetry (CV), chronoamperometry, amperometry and differential pulse voltammetry (DPV). CuFe₂O₄ nanoparticles were synthesized by co-precipitation method and characterized with scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) techniques. Then, a high conductive platform based on a carbon paste electrode modified with RGO and CuFe₂O₄ nanoparticles was prepared as a suitable platform for determination of hydrogen peroxide. Under the optimum conditions (pH5), the modified electrode indicated a fast amperometric response of <2s, good linear range of 2 to 200μM, low detection limit of 0.52μM for determination of hydrogen peroxide. Also, the peak current of differential pulse voltammetry (DPV) of hydrogen peroxide is increased linearly with its concentration in the ranges of 2 to 10μM and 10 to 1000μM. The obtained detection limit for hydrogen peroxide was evaluated to be 0.064μM by DPV. The designed sensor was successfully applied for the assay of hydrogen peroxide in biological and pharmaceutical samples such as milk, green tea, and hair dye cream and mouthwash solution.