Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
ACS Nano. 2012 Oct 23;6(10):9087-94. doi: 10.1021/nn303322r. Epub 2012 Sep 17.
A nanofluidic device is described that is capable of electrically monitoring the driven translocation of DNA molecules through a nanochannel. This is achieved by intersecting a long transport channel with a shorter orthogonal nanochannel. The ionic conductance of this transverse nanochannel is monitored while DNA is electrokinetically driven through the transport channel. When DNA passes the intersection, the transverse conductance is altered, resulting in a transient current response. In 1 M KCl solutions, this was found to be a current enhancement of 5-25%, relative to the baseline transverse ionic current. Two different device geometries were investigated. In one device, the DNA was detected after it was fully inserted into and translocating through the transport nanochannel. In the other device, the DNA was detected while it was in the process of entering the nanochannel. It was found that these two conditions are characterized by different transport dynamics. Simultaneous optical and electrical monitoring of DNA translocation confirmed that the transient events originated from DNA transport through the nanochannel intersection.
一种能够通过纳米通道电动监测 DNA 分子驱动穿隧的纳流控装置，该装置通过与较长的运输通道相交来实现这一点。在 DNA 通过运输通道进行电动力学驱动时，监测这个横向纳米通道的离子电导率。当 DNA 通过交点时，横向电导会发生变化，从而导致瞬态电流响应。在 1 M KCl 溶液中，与基线横向离子电流相比，这导致电流增强了 5-25%。研究了两种不同的器件几何形状。在一种器件中，当 DNA 完全插入并穿过运输纳米通道时，对 DNA 进行检测。在另一种器件中，在 DNA 进入纳米通道的过程中对其进行检测。发现这两种情况的传输动力学不同。DNA 穿隧的光学和电学同时监测证实，瞬态事件源自 DNA 通过纳米通道交点的传输。
