Lagerqvist Johan, Zwolak Michael, Di Ventra Massimiliano
Department of Physics, University of California, San Diego, La Jolla, California, USA.
Biophys J. 2007 Oct 1;93(7):2384-90. doi: 10.1529/biophysj.106.102269. Epub 2007 May 25.
We study theoretically the feasibility of using transverse electronic transport within a nanopore for rapid DNA sequencing. Specifically, we examine the effects of the environment and detection probes on the distinguishability of the DNA bases. We find that the intrinsic measurement bandwidth of the electrodes helps the detection of single bases by averaging over the current distributions of each base. We also find that although the overall magnitude of the current may change dramatically with different detection conditions, the intrinsic distinguishability of the bases is not significantly affected by pore size and transverse field strength. The latter is the result of very effective stabilization of the DNA by the transverse field induced by the probes, so long as that field is much larger than the field that drives DNA through the pore. In addition, the ions and water together effectively screen the charge on the nucleotides, so that the electron states participating in the transport properties of the latter ones resemble those of the uncharged species. Finally, water in the environment has negligible direct influence on the transverse electrical current.
我们从理论上研究了利用纳米孔内的横向电子输运进行快速DNA测序的可行性。具体而言，我们考察了环境和检测探针对DNA碱基可区分性的影响。我们发现，电极的固有测量带宽通过对每个碱基的电流分布进行平均，有助于单个碱基的检测。我们还发现，尽管在不同检测条件下电流的总体大小可能会发生显著变化，但碱基的固有可区分性不受孔径和横向场强的显著影响。后者是由于探针诱导的横向场对DNA的稳定作用非常有效，只要该场远大于驱动DNA通过纳米孔的场。此外，离子和水共同有效地屏蔽了核苷酸上的电荷，使得参与后者输运性质的电子态类似于不带电物种的电子态。最后，环境中的水对横向电流的直接影响可忽略不计。
