Abstract
► A novel H2O2 chemical sensor (PDDA-G/Fe3O4)5 multilayer films modified ITO electrode. ► Fabricated by means of the layer-by-layer assembly method. A wide linear range from 20μM to 6.25mM. ► Much wider than some reported biosensors based on horseradish peroxidase.
In this article, poly(diallydimethylammonium chloride) (PDDA) functionalized graphene-Fe3O4 (PDDA-G/Fe3O4)n multilayer films were fabricated with layer-by-layer assembly of negatively charged Fe3O4 nanoparticles (Fe3O4 NPs) and positively charged PDDA-G through the electrostatic interaction to construct a H2O2 chemical sensor. The multilayer films were characterized with UV–vis spectroscopy, atomic force microscopy and cyclic voltammetry. The participation of PDDA-G improved the catalytic ability of Fe3O4 NPs due to its high surface area and excellent electric conductivity. Based on this, the obtained H2O2 chemical sensor exhibited prominent electrocatalytic activity for the detection of H2O2 with a wide linear range from 20μM to 6.25mM, a rapid response upon the addition of H2O2 and a low detection limit of 2.5μM with the signal to noise ratio of three. Furthermore, the fabricated nonenzymatic H2O2 chemical sensor exhibited excellent stability and reproducibility.