Investigation of Charge Transport Along the DNA Double Helix

这个实验凝聚态物理程序将调查的温度和频率依赖的传输特性和电荷激发光谱的DNA双螺旋的各种修改。 所采用的方法-在微波和毫米波频率下测量电损耗-允许在不应用电接触的情况下确定电导率和介电常数，并将用于光学研究。 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双链体;还将研究各种抗衡离子、缓冲液环境和变性的影响。 这些实验将阐明电子和离子电荷沿着双螺旋的传输过程，将导致有关无序、分子波动和电子之间相互作用的作用的信息，从而区分已提出的不同模型。 这些研究也将为研究与生物过程相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，其与遗传现象有关的功能和性质是众所周知的。 对其基本物理性质的研究较少，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。 这一实验凝聚态物理方案将通过在射频、微波和光学频率下进行实验，研究DNA双螺旋上电子和离子电荷的运动。 这样的实验应该可以确定DNA是纳米导体还是半导体，并有助于澄清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能是有用的诊断工具，用于检测与遗传事件有关的分子特性。

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.