Synthesis, characterization, and sensing applications of polypyrrole coated Fe3O4 nanostrip bundles

This study focuses on the synthesis, characterization, electrical properties and use of polypyrrole-coated Fe3O4 nanostrip bundles (PPy/Fe3O4 NBs) as an enzyme-less sensor for the detection of hydrogen peroxide (H2O2) and lead (II) ions in hazardous materials. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) results confirm the presence of Fe3O4 nanostrip bundles coated by PPy. An electrochemical sensor based on the PPy/Fe3O4 NBs for the amperometric determination of H2O2 is prepared. Cyclic voltammetry experiments are performed on the PPy/Fe3O4 NBs/GCE to investigate the electrochemical behavior of Pb2+. The glassy carbon electrode (GCE) modified with PPy/Fe3O4 NBs shows enhanced amperometric response for the detection of H2O2. The detection limit, limit of quantification and sensitivity (S/N=3) for the linear segment are estimated to be 0.4715 µmol L−1, 1.5719 µmol L−1 and 40.7870 µA mM−1, respectively. The calibration curve corresponding to the cyclic voltammetry response for the PPy/Fe3O4 NBs/GCE shows two linear segments for the detection of Pb(II). The sensitivity obtained for the two linear segments (low: from 10 to 50 nmol L−1 and high: 50 to 100 nmol L−1 concentration of Pb(II)) is estimated to be 0.0459 µA nM−1 and 2.7599 µA nM−1, respectively. The results show that the morphology of the PPy/Fe3O4 NBs can provide a highly available surface area for the interaction with H2O2 and Pb(II).