Impedimetric sensor for iron (III) detection based on small molecule (E)-2-((phenylimino)methyl) phenol-modified platinum electrode

The critical role of ferric ions in biological system and health impact posed to humans due to related toxicity caused by the consumption of iron-contaminated drinking water or food, as well as exposure to the other environmental sector, needs a sensitive method for the determination of these ions in various domains such us medical uses, biological and environmental samples. Herein, a novel impedimetric sensor based on the bases Schiff molecule, (E)-2-((phenylimino)methyl) phenol ( E-PNMP ), was investigated for the quantification of ferric ions. The ability to recognize ferric ions with E-PNMP was characterized by UV–Vis, which indicated that we obtained a complex E-PNMP /Fe 3+ with a stoichiometry (1:2). The E-PNMP -modified electrode was characterized by electrochemical impedance spectroscopy (EIS). Under the optimal conditions, the proposed impedimetric sensor exhibits a limit of detection of 2.49 × 10 –12 M in the range of concentration from 10 –12 to 10 –5 M. Thus, the investigated impedimetric sensor showed high sensibility, selectivity, reproducibility, and repeatability. A Pt/ E-PNMP electrode was successfully applied for the determination of iron (III) in a real sample. Furthermore, to better understand the sensing mechanism of E-PNMP /iron, a computational study with DFT was conducted using the B3LYP functional and the 6311++G (d, p) basis set. The theoretical studies confirmed the formation of the complex Fe 3+ : E-PNMP 2 with high stability.