Modification of DNA towards high conductance and transport measurements with controllable electrodes

利用可控电极修改 DNA 以实现高电导和传输测量

• 批准号: 25049854
• 负责人: Professor Dr. Artur Philipp Nikolaus Erbe
• 金额: --
• 依托单位: Arbeitsgruppe Mesoskopische Systeme
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/25049854?language=en
• 关键词: Modification; DNA; towards; conductance; transport

We investigate the electronic transport through synthetic DNA molecules contacted by the mechanically controllable breakjunction technique (MCB) with thiol bonds to gold electrodes. This allows on the one hand to use short sequences (10 to 30 basepairs) which is favorable to have a measurable current and on the other hand to vary the distance of the electrodes for the same molecule. The latter is important to investigate the influence of the structure of the molecules on the transport properties at the very same molecule. With special linking arms, part of the conformational changes can be suppressed (so-called LNA: locked DNA). Measurements on LNA will serve as reference for the unlocked DNA.An important issue in the transport through DNA is the role of the sequence. Competing theoretical models predict different sequences that should be favorable. A high electron transfer rate is predicted for pure CG (cytosine-guanine) DNA. However, this sequence is not stable in the usual conformation. Pure AT (adenine-thymine) DNA has been shown experimentally to have no significant conformational change while the predictions for charge transport are contradictory. We will investigate systematically different sequences. In the light of existing experiments natural DNA appears to be too resistive to serve as conductors in molecular electronics. However, the methods to create synthetic DNA with arbitrary sequence are very elevated. Consequently, if finally the influence of the contacts and conformation is revealed, DNA-based hybrid materials will be developed that give rise to high conductance values.In summary: the goal of the project is threefold. At first we want to clarify the transport mechanism of the DNA molecule. A prerequisite for this aim is to find a suitable, reproducible contacting method (goal 2). The third and final goal would then be to develop modifications of DNA that result in high conductance.

我们研究了通过机械可控断裂结技术（MCB）与巯基键连接到金电极的合成DNA分子的电子输运。这一方面允许使用有利于具有可测量电流的短序列（10至30个碱基对），另一方面允许改变相同分子的电极距离。后者对于研究分子结构对同一分子的输运性质的影响很重要。通过特殊的连接臂，可以抑制部分构象变化（所谓的LNA：锁定DNA）。对LNA的测量将作为解锁DNA的参考。在DNA的运输中的一个重要问题是序列的作用。相互竞争的理论模型预测了不同的有利序列。一个高的电子转移速率预测纯CG（胞嘧啶鸟嘌呤）DNA。然而，该序列在通常的构象中不稳定。纯AT（腺嘌呤-胸腺嘧啶）DNA已被实验证明没有显着的构象变化，而电荷传输的预测是矛盾的。我们将系统地研究不同的序列。根据现有的实验，天然DNA的电阻似乎太大，不能作为分子电子学中的导体。然而，创造具有任意序列的合成DNA的方法非常高。因此，如果最终发现接触和构象的影响，将开发出基于DNA的混合材料，从而产生高电导值。总之：该项目的目标有三个。首先，我们想弄清楚DNA分子的运输机制。实现这一目标的先决条件是找到合适的、可再现的接触方法（目标2）。第三个也是最后一个目标将是开发导致高电导率的DNA修饰。