Peroxidase-like activity and amperometric sensing of hydrogen peroxide by Fe2O3 and Prussian Blue-modified Fe2O3 nanoparticles

Nano-sized crystals of iron oxide (Fe2O3) was synthesized from a single-source precursor complex [Fe-3(mu(3)-O)(O2CCH2CI)(6)(H2O)(3)]NO3 center dot H2O by solvothermal process. Afterward it was chemically modified with electro-active Prussian Blue (PB). The resulting Fe2O3 and PB-Fe2O3 nanoparticles (NPs) were characterized by X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), UV-vis and IR spectroscopic techniques. Structural analyses showed that the average diameter of hexagonal Fe2O3 (maghemite) and PB-Fe2O3 NPs are 40 and 46 nm, respectively. The as-synthesized nanocomposite (PB-Fe2O3 NPs) showed superior catalytic activity toward oxidation of peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) in presence of H2O2 and follow typical Michaelis-Menten kinetics. Furthermore, the nanocomposite, immobilized on surface of a glassy carbon electrode (GCE), exhibited electrocatalytic activity toward reduction of hydrogen peroxide and can be used for its amperometric detection. (c) 2012 Elsevier B.V. All rights reserved.