Novel electrochemical sensor based on NiZnFe2O4/CPE for measurement of p-coumaric acid in honey samples

Abstract

One of the most abundant phenolic acids in honey is p-coumaric acid (PCA), which can be used to detect natural honey by examining its presence or absence along with its concentration. In this study, a new electrochemical sensor based on carbon paste electrode modified with NiZnFe2O4 nanospinels was designed to measure PCA in honey using differential pulse voltammetry (DPV). NiZnFe2O4 nanospinels were synthesized from iron (III) nitrate nonahydrate, nickel (II) nitrate hexahydrate, and zinc (II) nitrate hexahydrate in a ratio of 1:1:4 by sol-gel method. The presence of Fe, Ni, Zn, and O elements in porous and homogeneous nanoparticles was confirmed by energy dispersive X-ray (EDX) spectroscopy and the size of nanoparticles was 100 nm by transmission electron microscopy (TEM). Examination of PCA oxidation peaks in DPV voltammograms shows that potentials shift to more negative values (from 0.8 to 0.7 V) as the amount of nanospinel increases indicating the decrease in overpotential after CPE modification by the nanospinel. DPV voltammograms of PCA samples with different concentrations, NiZnFe2O4/CPE was successfully used to measure PCA in two samples of thyme and astragalus honey and the estimated values were 3.41 ×10-5 and 1.705 × 10-5 M, respectively. The stability and reproducibility of the electrode were confirmed after examination over 16 days.