Cytochrome c assembly on fullerene nanohybrid metal oxide ultrathin films

Abstract

The immobilization of Cyt. c (cytochrome c) on C₆₀ (fullerene) nanohybrid TiO₂ (titanium dioxide) gel films assembled with C₆₀, Ti(O–ⁿBu)₄ and Cyt. c was realized by a surface sol–gel process. Interestingly, C₆₀ was used without any surface modification of the film formation and exhibited good electrochemical performance. Additionally, the surface morphologies of the TiO₂ and TiO₂/C₆₀ nanocomposite thin films showed remarkable uniformity over a wide area, however, the surface morphology depends on the deposition of Cyt. c, which densely covers the surface with adsorbed Cyt. c molecules. The cyclic voltammetry of the outer-most fullerene films revealed high stability, as well as, a pair of current peaks characteristic of a weak redox system with anodic and cathodic peak potentials at 0.262 V and 0.137 V. The electrochemical properties of thin films can be attributed to the redox system of the C₆₀ layer deposited on the TiO₂ gel layer. A pair of well-defined quasi-reversible redox peaks generated by Cyt. c are easily achieved because of the efficient assembly on the C₆₀-modified electrode. In this work, we suggest the efficient introduction of C₆₀ into a TiO₂ gel matrix, evaluating the electrochemical characteristics of Cyt. c assembly.