Electrically Tunable Quenching of DNA Fluctuations in Biased Solid-State Nanopores.
Electrically Tunable Quenching of DNA Fluctuations in Biased Solid-State Nanopores.
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DOI：
10.1021/acsnano.6b00226
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发表时间：
2016-04-26
期刊：
影响因子：
17.1
通讯作者：
Leburton JP
中科院分区：
文献类型：
--
作者：
Qiu H;Girdhar A;Schulten K;Leburton JP
纳米孔为广泛的纳米级材料提供传感器，特别是生物来源的材料，如单链和双链DNA或DNA-蛋白质复合物。为了增加单分子灵敏度，期望控制纳米孔内的生物分子运动。在本研究中，我们研究如何在双链DNA的情况下，可以通过偏置电压提高单分子的灵敏度。为了这个目的，我们进行分子动力学模拟的DNA内的纳米孔在电偏置的金属膜，通过使用分子动力学模拟。DNA的稳定，即减少热波动，观察到在正偏压下，而负电压带来的稳定性可以忽略不计。对于正偏压，稳定化由带负电荷的DNA骨架和带正电荷的孔表面之间的静电吸引引起。对泪珠形孔的模拟显示，在正偏压下，DNA位置向孔的尖锐端横向移动，这表明通过几何形状来控制纳米孔内的DNA排列的可能性。目前的研究结果为降低热噪声开辟了一条可行而有效的途径，从而提高了单分子纳米孔传感的信噪比。
Nanopores offer sensors for a broad range of nanoscale materials, in particular ones of biological origin like single- and double-stranded DNA or DNA-protein complexes. In order to increase single-molecule sensitivity, it is desirable to control biomolecule motion inside nanopores. In the present study, we investigate how in case of a double-stranded DNA the single-molecule sensitivity can be improved through bias voltages. For this purpose we carry out molecular dynamics simulations of the DNA inside nanopores in an electrically biased metallic membrane, by using molecular dynamics simulations. Stabilization of DNA, namely a reduction in thermal fluctuations, is observed under positive bias voltages, while negative voltages bring about only negligible stabilization. For positive biases the stabilization arises from electrostatic attraction between the negatively charged DNA backbone and the positively charged pore surface. Simulations on a teardrop-shape pore show a transverse shift of DNA position toward the sharp end of the pore under positive bias voltages, suggesting the possibility to control DNA alignment inside nanopores through geometry shaping. The present findings open a feasible and efficient route to reduce thermal noise, and in turn, enhance the signal-to-noise ratio in single-molecule nanopore sensing.