Synthesis of a hierarchically structured Fe3O4–PEI nanocomposite for the highly sensitive electrochemical determination of bisphenol A in real samples

Abstract

In this work, a novel, highly sensitive and cost-effective sensing electrode was fabricated for the sensitive detection of bisphenol A in milk and water samples. An eco-catalyst Fe₃O₄–PEI nanocomposite was successfully synthesized using a hydrothermal method. XRD, XPS, TEM, FE-SEM, FTIR spectroscopy and a Zetasizer were employed to analyse the morphology, elemental composition and surface charge of the Fe₃O₄–PEI nanocomposite. A simple cyclic voltammetry technique was used for the sensitive detection of BPA on the Fe₃O₄–PEI/C electrode. The positive surface charge of the composite remarkably enhanced the sensitivity toward BPA. Under optimized conditions, the Fe₃O₄–PEI/C electrode showed high electrochemical sensitivity and good catalytic activity toward BPA. A wide linear sensitivity range from 0.01 μM to 50 μM with a high correlation coefficient of 0.99524 and a limit of detection (LOD) of 3.2 nM (S/N = 3) toward BPA were obtained for the Fe₃O₄–PEI/C electrode. The proposed electrode (Fe₃O₄–PEI/C) successfully detected BPA in milk and water samples with high recovery percentages of 100.9% and 100.5%, respectively. The results obtained using the proposed electrode (Fe₃O₄–PEI/C) correlated well with GC-MS data for real samples. A novel Fe₃O₄–PEI/C electrode exhibited high sensitivity, stability, and selectivity in BPA detection. Fe₃O₄–PEI/C shows high electrochemical activity toward 2,4-dinitrophenol as well. The proposed Fe₃O₄–PEI/C electrode is a highly convenient tool for the simultaneous detection of BPA and other phenolic compounds in real samples.