Enhancing Analytical Performance of (Mg,Fe)3O4/Glassy Carbon Electrodes by Tailoring Chemical Composition of (Mg,Fe)3O4 Nanoparticles

Abstract

A series of MgxFe3-xO₄ (x ═ 0-1) nanoparticles was synthesized in order to prepare novel MgxFe3-xO₄/glassy carbon modified electrodes. Effects of magnesium content (x) on the analytical performance of the modified electrodes in the detection of gallic acid were evaluated. It was found that magnesium concentration and crystallite/particle size of the prepared nanoparticles play significant roles in the sensing properties of modified electrodes. The increase of magnesium concentration up to the value of x ═ 0.4 in MgxFe3-xO₄/glassy carbon paste was accompanied by an increase of the corresponding oxidation current of gallic acid. However, further growth of x value caused decline of the obtained oxidation current. An electroanalytical procedure was established, and the analytical performance of the proposed Mg0.4Fe2.6O₄/glassy carbon paste electrode was monitored using previously optimized experimental conditions. A working linear range from 1-39 µM gallic acid was obtained with detection limit of 0.29 µM. According to these results, the developed procedure can be applied for detection of low concentrations of gallic acid with satisfactory selectivity in the presence of some common naturally occurring compounds. Experimental results indicate that the developed procedure could be a novel approach in the detection of antioxidant, overcoming some known disadvantages such as passivation, and could be a promising replacement for sophisticated chromatographic methods.