Electrocatalysis of Hemoglobin in ZnO Nanoparticle/ionic Liquid Composite Film Modified Glassy Carbon Electrode

A nanobiocompatible composite containing hemoglobin (Hb), ZnO nanoparticles (nano-ZnO) and ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6) was fabricated and further modified on the glassy carbon electrode (GCE). The electrochemical behaviours of Hb in the composite film were carefully studied and a pair of quasi-reversible redox peaks appeared in pH 7.0 phosphate buffer solution, which was attributed to the electrode reaction of Hb heme Fe(III)/Fe(II) redox couple. The presences of nano-ZnO and BMIMPF6 in the film can retain the bioactivity of lib and greatly enhance the direct electron transfer of Hb. The immobilized Hb showed high stability and good electrocatalytic ability to the reduction of hydrogen peroxide and O-2.