Bioelectrocatalytic current based on direct heterogeneous electron transfer reaction of glucose oxidase adsorbed onto multi-walled carbon nanotubes synthesized on platinum electrode surfaces

Multi-walled carbon nanotubes (MWCNTs) were synthesized on platinum plate electrodes by the chemical vapor deposition (CVD) method. The MWCNTs synthesized on the Pt plate (MWCNTs/Pt) electrode were immediately immersed into solutions of glucose oxidase (GOX) to immobilize these enzymes onto the MWCNTs/Pt electrode surfaces. After the GOX was immobilized onto the MWCNTs/Pt electrode, a well-defined catalytic oxidation current was increased from ca. ?0.45 V (vs. Ag/AgCl/saturated KCl), which was close to the redox potential of flavin adenine dinucleotide (FAD) as a prosthetic group of GOX under physiological pH values.