Investigation of Charge Transport Along the DNA Double Helix

这个实验凝聚态物理程序将研究DNA双螺旋结构的各种修饰的温度和频率相关的输运性质和电荷激发谱。所采用的方法-测量微波和毫米波频率下的电损耗-允许在不使用电接触的情况下确定电导率和介电常数，并将与光学研究结合使用。待研究的DNA修饰包括具有定制碱基对序列的合成DNA低聚物，以及天然DNA双链；还将研究各种反离子、缓冲环境和变性的影响。实验将揭示电子和离子电荷沿双螺旋的传输过程，将导致有关无序作用的信息，分子波动和电子之间的相互作用，并将因此区分不同的模型已经提出。这些研究也将为研究与生物过程有关的电子效应奠定基础，例如辐射引起的缺陷和修复。DNA是一种重要的生物分子，其功能和特性与遗传现象有关。研究较少的是其基本物理性质，例如电荷迁移等电子过程，这可能与氧化过程和辐射引起的损伤和修复机制有关。这个实验凝聚态物理项目将通过在射频、微波和光学频率下进行实验，研究DNA双螺旋结构上电子和离子电荷的运动。这样的实验可以确定DNA是纳米级导体还是半导体，并有助于阐明可能具有生物学意义的电子机制。从长远来看，研究电荷迁移的技术也可以作为检测与遗传事件相关的分子特性的诊断工具。

This experimental condensed matter physics program will investigate the temperature and frequency dependent transport properties and charge excitation spectra of the various modifications of the DNA double helix. The method employed - the measurement of the electric loss at micro and millimeter wave frequencies - allows the determination of the conductivity and dielectric constant without applying electrical contacts, and will be used in combination of optical studies. The DNA modifications to be investigated include synthetic DNA oligomers with tailor-made base pair sequences, together with native DNA duplexes; the influence of various counter ions, buffer environment and denaturing will also be studied. The experiments will shed light on the electronic and ionic charge transport process along the double helix, will lead to information concerning the role of disorder, molecular fluctuations and interactions between the electrons and will thus distinguish between the different models which have been proposed. These studies will also lay the groundwork for the investigation of electronic effects associated with biological processes, such as radiation induced defects and repair.%%%DNA is an important biological molecule whose function and properties in connection with genetic phenomena are well known. Less studied are its fundamental physical properties, for example electronic processes such as charge migration, which may be related to oxidation processes and radiation-caused damage and repair mechanisms. This experimental condensed matter physics program will study the motion of electronic and ionic charges on the DNA double helix by conducting experiments at radio frequency, microwave and optical frequencies. Such experiments should determine whether DNA is a nanoscale conductor or semiconductor and help clarify electronic mechanisms of possible biological significance. In the long term the techniques to be developed to study charge migration may also be useful as diagnostic tools for the detection of molecular properties related to genetic events.