Electrochemical and spectroelectrochemical characterization of different mesoporous TiO 2 film electrodes for the immobilization of Cytochrome c

• Published in: Frontiers of materials science 2018, Vol.12 (1), p.64-73
• Main Authors: KATSIAOUNIS, Stavros, TIFLIDIS, Christina, TSEKOURA, Christina, TOPOGLIDIS, Emmanuel
• Format: Article
• Language: English
• Subjects: cyclic voltammetry; Cytochrome c; spectroelectrochemistry; TiO 2 films
• ISSN: 2095-025X; 2095-0268
• DOI: 10.1007/s11706-018-0406-3

In this work three different mesoporous TiO 2 film electrodes were prepared and used for the immobilization of Cytochrome c (Cyt-c). Films prepared via a standard sol-gel route (SG-films) were compared with commercially available benchmark nanotitania materials, namely P25 Degussa (P25-films) and Dyesol nanopaste (Dyesol films). Their properties, film deposition characteristics and their abilities to adsorb protein molecules in a stable and functional way were examined. We investigated whether it is possible, rather than preparing TiO 2 films using multistep, lengthy and not always reproducible sol-gel procedures, to use commercially available nanotitania materials and produce reproducible films faster that exhibit all the properties that make TiO 2 films ideal for protein immobilization. Although these materials are for mulated primarily for dye-sensitized solar cell applications, in this study we found out that protein immobilization is facile and remarkably stable on all of them. We also investigated their electrochemical properties by using cyclic voltammetry and spectroelectrochemistry and found out that not only direct reduction of Fe(III)-heme to Fe(II)-heme of immobilized Cyt-c was possible on all films but that the adsorbed protein remained electroactive.