Development of an Amperometric Hydrogen Peroxide Biosensor based on the Immobilization of Horseradish Peroxidase onto Nickel Ferrite Nanoparticle-Chitosan Composite

Nickel ferrite (NiFe 2 O 4 ) nanoparticles have been dispersed in chitosan solution in order to fabricate nanocomposite films. Horseradish peroxidase (HRP) has been immobilized onto this chitosan-NiFe 2 O 4 nanocomposite film via physical adsorption. The size of the NiFe 2 O 4 nanoparticles has been estimated using X-ray diffraction pattern and scanning electron microscopy (SEM) to be 40±9 nm. The chitosan-NiFe 2 O 4 nanocomposite film and HRP/chitosan-NiFe 2 O 4 bioelectrode have been characterized using SEM technique. The HRP/chitosan-NiFe 2 O 4 nanocomposite bioelectrode has a response time of 4 s, linearity as 0.3 to 12mM of H 2 O 2 , sensitivity as 22 nA/mM. The effects of pH and the temperature of the immobilized HRP electrode have also been studied.