Surface functions of 2-mercaptopyridine, 2-mercaptopyrazine and 2-mercaptoquinoxaline modified Au(1 1 1) electrodes for direct rapid electron transfer of cytochrome c
Makaleler > Tam Makale · 2003
Yazarlar: Isao Taniguchi, Hitoshi Ishimoto, Keiko Miyagawa, Mitsuru Iwai, Hidenori Nagai, Hiroyuki Hanazono, Koichi Taira, Atsushi Kubo, Akiko Nishikawa, Katsuhiko Nishiyama, Zekerya DURSUN, George P.J. Hareau, Masato Tazaki
Electrochemistry Communications, SCI Expanded İndekslerine Giren Dergi, Uluslararası, Scopus, 2003, cilt 5, ss 857-861
DOI: 10.1016/j.elecom.2003.08.006
Özet
Surface functions of modified electrodes for the rapid electron transfer of cytochrome c have been examined by using new surface modifiers. 2-Mercaptopyrazine (2-PyZSH) and 2-mercaptoquinoxaline (or 2-mercaptobenzopyrazine, 2-MQ) modified Au(111) electrodes gave well-defined cyclic voltammmograms of cytochrome c, while a 2-mercaptopyridine (2-PySH) modified electrode gave no response. The STM images of 2-PySH and 2-PyZSH modified surfaces were similar to each other, suggesting 2-PySH and 2-PyZSH adsorbed at both thiolate S and pyridine (or pyrazine) N atoms with pyridine (or pyrazine) ring being perpendicular to the electrode surface. The 2-PyZSH modified surface has another pyrazine N atom faced to the solution, through which cytochrome c can interact, and the double layer capacitance data of the electrode gave more hydrophilic nature than the 2-PySH modified surface. On the other hand, although 2-MQ was suggested to adsorb on the electrode in a similar manner to 2-PySH and 2-PyZSH to give N atom at the solution side, the 2-MQ modified surface showed less hydrophilicity than the 2-PySH modified surface due to the quinoxaline ring. These results clearly reveal that the pyridine and pyrazine N atoms faced to the solution (rather than the hydrophilicity of the electrode surface) are important for the rapid electron transfer of cytochrome c on these modified electrodes. © 2003 Elsevier B.V. All rights reserved.