Electrochemical oxidation of erythrosine at TiO2 nanoparticles modified gold electrode - An environmental application

•We report a novel electrochemical sensor for a food dye erythrosine by utilizing TiO2 nanoparticles modified gold electrode.•Active sensing area was increased due to the modification. Thus oxidation signal enhancement of the dye was appeared.•The quantitative analysis of the dye in trace level was also investigated by using differential pulse voltammetry technique.•The sensor showed high sensitivity, good selectivity and acceptable precision.

In the present paper, TiO2 nanoparticles were utilized to modify the gold electrode surface and to emphasize a useful technique for determination of a food dye, erythrosine. The utilized modifier was characterized by Scanning electronic microscopy (SEM), and X-ray diffraction (XRD) analysis. In the first portion of the work, the oxidation properties of the dye were examined at different pH ranging from 3.0-11.2, varying accumulation time and at different scan rates, by using the cyclic voltammetric technique. The number of electrons and protons involved in the reaction, and heterogeneous rate constant were calculated. The second portion of the work includes the appositeness of the estimated method for the detection of the dye in trace level by utilizing differential pulse voltammetric technique. In optimum conditions (supporting electrolyte pH, accumulation time, modifier amount) the peak current was proportional to the concentration in the range 0.1 μM-10.0 μM with detection limit 2.6 nM. The applicability of the proposed method was achieved for food industries as well as for environmental applications.

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