Kitagawa Kazuya, Morita Tomoyuki, Kimura Shunsaku
Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Kyoto 615-8510, Japan.
J Phys Chem B. 2005 Jul 28;109(29):13906-11. doi: 10.1021/jp050642e.
A helical hexadecapeptide immobilized on gold via a thiophenyl group at the N-terminal was analyzed by scanning tunneling microscopy under ultrahigh vacuum to obtain the I-V response at a molecular level. The attenuation factor of the electron transfer through the hexadecapeptide was determined by applying the Simons model to the I-V response to show better molecular conductance of the hexadecapeptide than dodecanethiol. Chemical modification at the C-terminal of the hexadecapeptide with a ferrocene unit, on the other hand, brought about significant changes in the I-V response, where the helical peptide became more conductive at the negative bias voltage. The molecular rectification behavior is due to the ferrocene unit regulating the direction of the electron transfer at the metal-molecule junction.
通过 N 端的硫苯基固定在金上的螺旋十六肽，在超高真空下用扫描隧道显微镜进行分析，以在分子水平上获得 I-V 响应。通过将西蒙斯模型应用于 I-V 响应来确定通过十六肽的电子转移衰减因子，结果表明十六肽的分子导电性优于十二烷硫醇。另一方面，用二茂铁单元对十六肽的 C 端进行化学修饰，导致 I-V 响应发生显著变化，其中螺旋肽在负偏压下变得更具导电性。分子整流行为是由于二茂铁单元调节了金属-分子结处电子转移的方向。
