Development of methodology to quantify electron transfer between single molecules

在本研究项目中，我们开发了第一种方法，通过使用扫描隧道显微镜的分子尖端来量化单个分子与相邻的另一个单个分子之间发生的电子转移。例如，这种方法使我们能够揭示氢键在短距离内比共价键更好地传导电子。此外，我们系统地研究了由各种化学相互作用介导的单分子之间的电子转移。这些研究为未来实现分子电子学提供了新的见解和现象。此外，我们还证明了基于测量单分子之间电子转移的方法可以实现DNA的单分子检测。利用单链DNA作为探针尖端，并且该DNA尖端和靶DNA的杂交诱导电子隧穿通过所得DNA双链体。

In the present research project, we developed the first methodology by using molecular tip of scanning tunneling microscopy to quantify electron transfer taking place between a single molecule and adjacent another single molecule. This methodology allowed us to, for example, reveal that a hydrogen bond conducts electrons better than a covalent bond at short range. Moreover, we systematically investigated the electron transfer between single molecules mediated by a variety of chemical interactions. These studies provided novel insights and phenomena mandatory for the future realization of molecular electronics.In addition, we demonstrated that single-molecule detection of DNA can be achieved based on the methodology for the measurement of the electron transfer between single molecules. Single-stranded DNA was utilized as a probe tip, and hybridization of this DNA tip and target DNA induce electron tunneling through the resulting DNA duplex.