@article{OenerQuerebilloDavidetal.2018, author = {{\"O}ner, Ibrahim Halil and Querebillo, Christine Joy and David, Christin and Gernert, Ulrich and Walter, Carsten and Driess, Matthias and Leimk{\"u}hler, Silke and Ly, Khoa Hoang and Weidinger, Inez M.}, title = {High electromagnetic field enhancement of TiO2 nanotube electrodes}, series = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition}, volume = {57}, journal = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition}, number = {24}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1433-7851}, doi = {10.1002/anie.201802597}, pages = {7225 -- 7229}, year = {2018}, 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 Cytochromeb(5) 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 degrees 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.}, language = {en} }