Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, Cx. Postal 6021, Fortaleza, Ceará, Brasil 60455-970.
J Phys Chem B. 2013 Jul 25;117(29):8673-80. doi: 10.1021/jp400694k. Epub 2013 Jul 16.
Quartz crystal microbalance (QCM), surface plasmon resonance (SPR), and electrochemistry techniques were used to study the electron-transfer (ET) reaction of cytochrome c (Cyt c) on gold surfaces modified with thionicotinamide, thioisonicotinamide, 4-mercaptopyridine, 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol, 5-phenyl-1,3,4-oxadiazole-2-thiol, 4,4'-bipyridine, and 4,4'-dithiopyridine. The electrochemical results showed that the ET process is complex, being chiefly diffusional with steps depending on the orientation of the pyridine or phenyl tail group of the modifiers. The correlation between the electrochemical results and those acquired by SPR and QCM indicated the presence of an adlayer of Cyt c adsorbed on the thiolate SAMs. This adlayer, although being not electroactive, is essential to assess the ET reaction of Cyt c in solution. The results presented in this work are consistent with the statement (Feng, Z. Q.; Imabayashi, S.; Kakiuchi, T.; Niki, K. J. Electroanal. Chem. 1995, 394, 149-154) that the ET reaction of Cyt c can be explained in terms of the through-bond tunneling mechanism.
石英晶体微天平（QCM）、表面等离子体共振（SPR）和电化学技术被用于研究金表面上修饰的硫代烟酰胺、硫代异烟酰胺、4-巯基吡啶、5-(4-吡啶基)-1,3,4-恶二唑-2-硫醇、5-苯基-1,3,4-恶二唑-2-硫醇、4,4'-联吡啶和 4,4'-二硫代吡啶上细胞色素 c（Cyt c）的电子转移（ET）反应。电化学结果表明，ET 过程是复杂的，主要是扩散过程，取决于修饰剂中吡啶或苯基尾部基团的取向。电化学结果与 SPR 和 QCM 获得的结果之间的相关性表明 Cyt c 的吸附在硫醇自组装单层（SAM）上存在一个吸附加层。尽管这个吸附加层没有电化学活性，但对于评估 Cyt c 在溶液中的 ET 反应是必不可少的。本工作中的结果与 Feng, Z. Q.; Imabayashi, S.; Kakiuchi, T.; Niki, K.（1995）的声明一致，即 Cyt c 的 ET 反应可以用通过键隧穿机制来解释。
