Direct Electrochemistry and Electrocatalysis of Myoglobin Immobilized on a Novel Chitosan-Nickel Hydroxide Nanoparticles-Carbon Nanotubes Biocomposite Modified Glassy Carbon Electrode

A novel myoglobin-based electrochemical biosensor was developed. thefabricated biosensor is based on a nanobiocomposite prepared from multiwalled carbonnanotubes and ni(oh)2 nanoparticles that were coated with myoglobin and chitosan. cyclicvoltammogram of the electrode showed a pair of well-defined and quasi-reversible redoxpeaks with a formal potential (e0') of –0.330 v in 0.1 m ph=7.5 phosphate buffer solution,which was the characteristic of the mb heme fe(iii)/fe(ii) redox couple. immobilized mbexhibits excellent electrocatalytic activity toward the reduction of hydrogen peroxide. thelinear range for the determination of hydrogen peroxide was from 0.4 to 702 ?m with adetection limit of 0.08 ?m using chronoamperometry method. the kinetic parameters such asthe electron transfer coefficient and the heterogeneous electron transfer rate constant for h2o2determination were determined using electrochemical approaches. the biosensor was usedfor determination of h2o2 in human blood serum and the oxidant with satisfactory results.