Effect of Noise on DNA Sequencing via Transverse Electronic Transport
Effect of Noise on DNA Sequencing via Transverse Electronic Transport
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DOI：
10.1016/j.bpj.2009.06.055
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发表时间：
2009-10-07
影响因子：
3.4
通讯作者：
Di Ventra, Massimiliano
中科院分区：
文献类型：
--
作者：
Krems, Matt;Zwolak, Michael;Di Ventra, Massimiliano
以前的理论研究表明，当DNA链通过纳米孔或通道转移时，测量DNA链上的横向电流可以提供DNA碱基的统计上可区分的特征，从而可以实现快速DNA测序。然而，环境的波动，如离子和DNA运动，引入了重要的散射过程，可能会影响这种测序方法的可行性。为了理解这个问题，我们分析了一个简单的模型，该模型捕捉了这种复杂环境在电子退相中的作用，以及它从载流态中移除电荷载流子的能力。我们发现，由于通过核苷酸隧穿的非共振性质，这些效应并没有强烈地影响电流分布--我们预计这将是分子结中输运的一个共同特征。特别是，与分子态和费米能级之间的能量间隙相比，只有较大的散射强度才会显著改变电流分布的形式。由于这一差距本身相当大，电流分布仍然受到保护，不受这种类型的噪声的影响，进一步支持了使用横向电子传输测量进行DNA测序的可能性。
Previous theoretical studies have shown that measuring the transverse current across DNA strands while they translocate through a nanopore or channel may provide a statistically distinguishable signature of the DNA bases, and may thus allow for rapid DNA sequencing. However, fluctuations of the environment, such as ionic and DNA motion, introduce important scattering processes that may affect the viability of this approach to sequencing. To understand this issue, we have analyzed a simple model that captures the role of this complex environment in electronic dephasing and its ability to remove charge carriers from current-carrying states. We find that these effects do not strongly influence the current distributions due to the off-resonant nature of tunneling through the nucleotides-a result we expect to be a common feature of transport in molecular junctions. In particular, only large scattering strengths, as compared to the energetic gap between the molecular states and the Fermi level, significantly alter the form of the current distributions. Since this gap itself is quite large, the current distributions remain protected from this type of noise, further supporting the possibility of using transverse electronic transport measurements for DNA sequencing.