Chang Hung, Venkatesan Bala Murali, Iqbal Samir M, Andreadakis G, Kosari F, Vasmatzis G, Peroulis Dimitrios, Bashir Rashid
Birck Nanotechnology Center, School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USA.
Biomed Microdevices. 2006 Sep;8(3):263-9. doi: 10.1007/s10544-006-9144-x.
Reports of DNA translocation measurements have been increasing rapidly in recent years due to advancements in pore fabrication and these measurements continue to provide insight into the physics of DNA translocations through MEMS based solid state nanopores. Specifically, it has recently been demonstrated that in addition to typically observed current blockages, enhancements in current can also be measured under certain conditions. Here, we further demonstrate the power of these nanopores for examining single DNA molecules by measuring these ionic currents as a function of the applied electric field and show that the direction of the resulting current pulse can provide fundamental insight into the physics of condensed counterions and the dipole saturation in single DNA molecules. Expanding on earlier work by Manning and others, we propose a model of DNA counterion ionic current and saturation of this current based on our experimental results. The work can have broad impact in understanding DNA sensing, DNA delivery into cells, DNA conductivity, and molecular electronics.
近年来，由于孔制造技术的进步，DNA转位测量的报告数量迅速增加，并且这些测量继续为通过基于MEMS的固态纳米孔进行的DNA转位物理研究提供见解。具体而言，最近已经证明，除了通常观察到的电流阻断外，在某些条件下还可以测量电流增强。在这里，我们通过测量这些离子电流作为施加电场的函数，进一步证明了这些纳米孔用于检测单个DNA分子的能力，并表明所得电流脉冲的方向可以为凝聚抗衡离子的物理性质和单个DNA分子中的偶极子饱和提供基本见解。在Manning等人早期工作的基础上，我们根据实验结果提出了一个DNA抗衡离子离子电流及其饱和的模型。这项工作在理解DNA传感、DNA导入细胞、DNA导电性和分子电子学方面可能具有广泛影响。
