Center for Bioelectronics and Biosensors, Biodesign Institute, School of Electrical, Energy and Computer Engineering, Arizona State University , Tempe, Arizona 85287-5801, United States.
ACS Nano. 2015 Jan 27;9(1):88-94. doi: 10.1021/nn506280t. Epub 2014 Dec 31.
Studying the structural and charge transport properties in DNA is important for unraveling molecular scale processes and developing device applications of DNA molecules. Here we study the effect of mechanical stretching-induced structural changes on charge transport in single DNA molecules. The charge transport follows the hopping mechanism for DNA molecules with lengths varying from 6 to 26 base pairs, but the conductance is highly sensitive to mechanical stretching, showing an abrupt decrease at surprisingly short stretching distances and weak dependence on DNA length. We attribute this force-induced conductance decrease to the breaking of hydrogen bonds in the base pairs at the end of the sequence and describe the data with a mechanical model.
研究 DNA 的结构和电荷输运性质对于揭示分子尺度过程和开发 DNA 分子的器件应用非常重要。在这里，我们研究了机械拉伸诱导的结构变化对单链 DNA 分子电荷输运的影响。对于长度从 6 到 26 个碱基对的 DNA 分子，电荷输运遵循跳跃机制，但电导对机械拉伸非常敏感，在令人惊讶的短拉伸距离下急剧下降，并且与 DNA 长度的依赖性较弱。我们将这种力诱导的电导降低归因于序列末端碱基对中氢键的断裂，并使用力学模型描述了这些数据。
