Preparation and Function of Oriented Monolayers of Helical Peptides

建立了垂直取向螺旋多肽自组装单分子膜的制备方法。一种是利用硫辛酸及其衍生物作为螺旋多肽与金表面的连接剂，另一种是利用螺旋多肽与氨基衍生表面形成席夫碱。在任何一种情况下，螺旋肽都被设计成具有高度的自组织能力。从三个方面研究了螺旋肽自组装膜的功能。首先，将电子媒介基团规整地排列在螺旋肽上，并研究了衍生螺旋肽SAM作为电子媒介的电子性质。螺旋多肽SAM显示出阳极光电流，这表明由于生色团沿螺旋轴均匀分布而具有良好的电子介导性。其次，制备了C端带有N-乙基咔唑基团的螺旋多肽SAM，并研究了其光电流的产生。实现了具有较高量子效率的阳极光电流。第三，将疏水螺旋肽与亲水性冠醚偶联。该两亲性化合物在金表面形成了纳米尺度的条状结构。有趣的是，通过以两亲化合物的单分子膜为支架，得到了具有原子厚度的PbS层网络。由于其介观尺度，PbS膜具有半导体性质。

The preparative methods for vertically oriented helical peptide self-assembled monolayers (SAM) were established. One way is to use lipoic acid and its derivative as a linker between helical peptides and gold surface, and the other is to use schiff-base formation between helical peptides and amino-derivatized surface. In either case, helical peptides are designed to be endowed with highly self-organizing potency. The functions of the helical peptide SAMs have been investigated in terms of three aspects. Firstly, electron mediating groups were regularly arranged along the helical peptide, and the electronic property of the derivatized helical peptide SAM as the electron mediator was studied. The helical peptide SAM showed an anodic photocurrent, suggesting a good electron mediating property due to regularly spacing chromophores along the helix axis. Secondly, a helical peptide SAM having an N-ethylcarbazolyl group at the C terminal was prepared, and the photocurrent generation was studied. An anodic photocurrent was realized with a relatively high quantum efficiency. Thirdly, a hydrophobic helical peptide was conjugated with a hydrophilic crown ether. The amphiphilic compound formed a strip-pattern in a nm-range on gold surface. Interestingly, a network of PbS layer with an atomic thickness was obtained by using the monolayer of the amphiphilic compound as a scaffold. The PbS membrane showed a semiconductive property due to its mesoscopic scale.