Direct electrochemistry of cytochrome c at a novel gold nanoparticles-attached [formula omitted] ions implantation-modified indium tin oxide electrode

Abstract

A NH 2 + ions implantation-modified indium tin oxide (NH 2/ITO) electrode was prepared and the existence of amino group on the electrode was verified by FT-IR spectra and X-ray photoelectron spectroscopy analysis (XPS). The gold nanoparticles (AuNPs) have been fabricated on the surface of NH 2/ITO electrode, resulting novel gold nanoparticles-attached NH 2 + ions implantation-modified ITO (AuNPs/NH 2/ITO) electrode, which could provide a biocompatible surface for the adsorption of cytochrome c (Cyt c). The Ultraviolet–visible (UV–vis) spectra indicated that Cyt c adsorbed on the AuNPs interface retained the native structure. Electrochemical impedance spectra (EIS) and cyclic voltammetric techniques were employed to evaluate the electrochemical behaviors of Cyt c. The surface of the AuNPs/NH 2/ITO electrode was exhibited using the scanning electron microscopy (SEM) comparing with the surface of the gold nanoparticles-attached ITO electrode (AuNPs/ITO). We found that the functional surface of the NH 2/ITO electrode resulted in a high AuNPs loading. The obtained Cyt c/AuNPs/NH 2/ITO electrode gave an excellent electrocatalytic activity towards the reduction of H 2O 2, and the catalysis currents were proportional to the H 2O 2 concentration in the range of 2.0–300.0 μM with a detection limit of 0.5 μM ( S/ N = 3).