Simultaneous electro-catalytic oxidative determination of ascorbic acid and folic acid using Fe3O4 nanoparticles modified carbon paste electrode

Abstract

The fabrication of magnetite (Fe3O4) nanoparticles modified carbon paste electrode (Fe3O4-CME) enabled facile electrochemical determination of ascorbic acid (AA) and folic acid (FA) using differential pulse voltammetry. Fe3O4 nanoparticles were synthesized by solution route and characterized by Fourier transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer and scanning electron microscopy. The nanoparticles were found to have an average diameter of 22nm. The electrochemical signals showed that Fe3O4-CME enhanced the rate of oxidation of AA and FA by increasing the peak current with a corresponding decline of peak potential compared to carbon paste electrode which makes the oxidation process thermodynamically more favorable. The modified electrode had a good sensitivity toward simultaneous determination of AA and FA in a linear working range of 9.09×10−7–4.70×10−3M and 6.50×10−8–9.80×10−5M with corresponding detection limits of 2.51×10−7M and 2.01×10−9M for AA and FA respectively. Electrochemical impedance spectroscopy was employed to understand the enhancement of the Fe3O4 nanoparticles modified carbon paste electrode over plain carbon paste electrode.