A Novel NH2/ITO Ion Implantation Electrode: Preparation, Characterization, and Application in Bioelectrochemistry

A novel NH2- ion implantation-modified indium tin oxide (NH2/ITO) electrode was prepared. Acid-pretreated, negatively charged MWNTs were firstly modified on the surface of NH2+ ion implantation electrode. then, positively charged Mb was adsorbed onto MWNTs films by electrostatic interaction, The assembly of MWNTs and Mb was characterized with electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The immobilized Mb showed a couple of quasireversible cyclic voltammetry peaks in pH 7.0 phosphate buffer solution (PBS). The apparent surface concentration of Mb at the electrode surface was 1.06 x 10(-9) mol cm(-2). The Mb/MWNTs/NH2/ITO electrode also gave an improved electrocatalytic activity towards the reduction of hydrogen peroxide. The catalysis currents increased linearly to the H2O2 concentration in a wide range from 9 x 10(-7) to 9.2 x 10(-5) M with a correlation coefficient of 0.999. The detection limit was 9.0 x 10(-7) M. The experiment results demonstrated that the modified electrode provided a biocompatible microenvironment for protein and supplied a necessary pathway for its direct electron transfer.