Sensing H2O2 with layer-by-layer assembled Fe3O4-PDDA nanocomposite film

It was found that Fe3O4 nanoparticles (Fe3O4 NPs) possess intrinsic enzyme mimetic activity similar to that found in natural peroxidase. Here, we applied Fe3O4 NPs to the construction of efficient electrochemical sensor to detect the concentration of hydrogen peroxide. The sensor was fabricated with layer-by-layer assembly of Fe3O4 NPs and poly(diallyldimethylammonium chloride) (PDDA) through the electrostatic interaction, and the multilayer film was characterized with UV-vis absorption spectra, atomic force microscopy, and cyclic voltammetry.