An amperometric hydrogen peroxide chemical sensor based on graphene-Fe3O4 multilayer films modified ITO electrode

► 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 20 μM to 6.25 mM. ► Much wider than some reported biosensors based on horseradish peroxidase.