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High Electromagnetic Field Enhancement of TiO2 Nanotube Electrodes |
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| Authors: | M?Sc Ibrahim Halil Öner M?Sc Christine Joy Querebillo Dr Christin David Dipl‐Ing Ulrich Gernert M?Sc Carsten Walter Prof?Dr Matthias Driess Prof?Dr Silke Leimkühler Dr Khoa Hoang Ly Prof?Dr Inez M Weidinger |
| Institution: | 1. Professur für Elektrochemie, Technische Universit?t Dresden, Dresden, Germany;2. Institut für Chemie, Technische Universit?t Berlin, Berlin, Germany;3. Madrid Institute for Advanced Studies in Nanoscience (IMDEA Nanoscience), Madrid, Spain;4. ZE Elektronenmikroskopie, Technische Universit?t Berlin, Sekr. KWT 2/ Abt. ZELMI, Berlin, Germany;5. Molecular Enzymology, University of Potsdam, Potsdam, Germany;6. Department of Chemistry, University of Cambridge, Cambridge, UK |
| Abstract: | We present the fabrication of TiO2 nanotube electrodes with high biocompatibility and extraordinary spectroscopic properties. Intense surface‐enhanced resonance Raman signals of the heme unit of the redox enzyme Cytochrome b5 were observed upon covalent immobilization of the protein matrix on the TiO2 surface, revealing overall preserved structural integrity and redox behavior. The enhancement factor could be rationally controlled by varying the electrode annealing temperature, reaching a record maximum value of over 70 at 475 °C. For the first time, such high values are reported for non‐directly surface‐interacting probes, for which the involvement of charge‐transfer processes in signal amplification can be excluded. The origin of the surface enhancement is exclusively attributed to enhanced localized electric fields resulting from the specific optical properties of the nanotubular geometry of the electrode. |
| Keywords: | electromagnetic field enhancement photonic crystals spectro-electrochemistry surface-enhanced Raman spectroscopy TiO2 nanotubes |