Fabrication, characterization of Fe3O4 multilayer film and its application in promoting direct electron transfer of hemoglobin

Fe3O4 magnetic multilayer films were constructed on several conductive bases (glassy carbon electrode, ITO glass and Al foil) by the firstly electrodeposited chitosan/Fe3O4 nanoparticles thin film and then the layer-by-layer assembly using phytic acid and Fe3O4/chitosan. Scanning electronic microscopy (SEM), UV–vis spectra, electrochemical impedance spectroscopy (EIS) and superconducting quantum interference device (SQUID) measurements were used to characterize the multilayer films. Characteristic superparamagnetic properties of Fe3O4 nanoparticles are well remained in the film and could be controlled simply by changing the assembly layers. Moreover, the multilayer film showed good biocompatibility, the adsorbed hemoglobin (Hb) on the film realized direct electron transfer with the underlying GCE and kept high catalytic activity. This presented system avoid the complex synthesis for protecting Fe3O4 nanoparticles, and supplies a simple, universal way to construct other nanoparticles films on many conductive bases for biosensors’ development.