DNA-mediated fluctuations in ionic current through silicon oxide nanopore channels
DNA-mediated fluctuations in ionic current through silicon oxide nanopore channels
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DOI：
10.1021/nl049267c
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发表时间：
2004-08-01
期刊：
影响因子：
10.8
通讯作者：
Bashir, R
中科院分区：
文献类型：
--
作者：
Chang, H;Kosari, F;Bashir, R
生物膜或人工膜中的纳米孔作为机械门控元件的单分子传感器在核酸分子的快速表征和测序方面具有很好的应用前景。聚合物通过单离子通道和单链DNA分子通过蛋白质通道的两端电学测量已经被证明，并引起了人们对这种单分子传感器的极大兴趣。关于纳米孔传感器的主流观点是，纳米孔和移位分子之间不存在电学相互作用，而且迄今为止报道的所有纳米孔传感器，无论是生物的还是人工的，都是作为库尔特计数器运行的，即当DNA分子穿过孔洞时，测量到的穿过孔洞的离子电流减少(被机械地阻止)。我们已经制造了具有二氧化硅内表面的纳米孔“通道”传感器，我们的结果挑战了dsDNA分子通过这些通道移位期间排他性机械相互作用的主流观点。我们证明，由于DNA本身的电荷，通道中表面电流的电门实际上可以增加离子电流。
Single molecule sensors in which nanoscale pores within biological or artificial membranes act as mechanical gating elements are very promising devices for the rapid characterization and sequencing of nucleic acid molecules. The two terminal electrical measurements of translocation of polymers through single ion channels and that of ssDNA molecules through protein channels have been demonstrated, and have sparked tremendous interest in such single molecule sensors. The prevailing view regarding the nanopore sensors is that there exists no electrical interaction between the nanopore and the translocating molecule, and that all nanopore sensors reported to-date, whether biological or artificial, operate as a coulter-counter, i.e., the ionic current measured across the pore decreases (is mechanically blocked) when the DNA molecule transverses through the pore. We have fabricated nanopore "channel" sensors with a silicon oxide inner surface, and our results challenge the prevailing view of exclusive mechanical interaction during the translocation of dsDNA molecules through these channels. We demonstrate that the ionic current can actually increase due to electrical gating of surface current in the channel due to the charge on the DNA itself.