Enhanced Performance of CNT-doped Imine Based Receptors as Fe(III) Sensor Using Potentiometry and Voltammetry

Abstract

A highly sensitive and selective potentiometric and voltammteric assay for the detection of Fe3+ using (E)-3-((2-(2-(2-aminoethylamino) ethylamino) ethylimino)methyl)-4H-chromen-4-one (IFE(III)) ionophore was developed. To demonstrate the ion-to-electron transfer ability of MWCNT, these were incorporated in the ion-selective membrane and response characteristics of Fe3+ electrode was compared with those of the traditional ion selective electrode. The electrode showed an improved Nernstian slope, lower detection limit, response time of less than 5 s and working in a pH range of 3.0 to 8.0. Differential pulse voltammetric studies were performed for IFE(III)-Fe3+ complex in DMSO solvent medium at glassy carbon (GC) electrode. A linear relationship between the cathodic peak current and concentration of Fe3+ was observed in the range of 1.6×10−5 to 4.4×10−5 mol/L with a detection limit of 5.2×10−8 mol/L. The electrode shows remarkable selectivity for Fe3+ ions over alkali, alkaline earth, transition and heavy metal ions. The optimized electrode was successfully applied for the determination of Fe3+ ion in different real-life samples using potentiometric technique. Theoretical calculations were used to support the complexation behavior of Fe3+ with IFE(III).