A tip-attached tuning fork sensor for the control of DNA translocation through a nanopore.
A tip-attached tuning fork sensor for the control of DNA translocation through a nanopore.
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DOI：
10.1063/1.4974955
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发表时间：
2017-02
期刊：
影响因子：
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通讯作者：
Changbae Hyun;H. Kaur;Taoxian Huang;Jiali Li
中科院分区：
文献类型：
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作者：
Changbae Hyun;H. Kaur;Taoxian Huang;Jiali Li
在这项工作中，我们证明了音叉可以作为力检测传感器来操纵DNA分子，并控制通过纳米孔的DNA移位率。音叉的一个尖头粘着一个探针尖端，DNA分子可以附着在探头尖端上。为了控制尖端的运动和位置，音叉被固定在具有亚纳米位置控制的纳米定位系统上。流体室是为了满足实验的许多要求而设计的：用于接近纳米孔的DNA连接尖端的访问，用于容纳纳米孔芯片，以及用于用一对电极测量通过固态纳米孔的离子电流。首先用透射电子显微镜观察纳米孔的位置，然后用光学显微镜结合局部扫描纳米孔表面上的探针尖端来确定液室内的位置。当DNA固定的尖端接近纳米孔附近的膜表面时，固定的DNA串的自由端可以通过穿过纳米孔芯片的施加电压被拉并捕获到孔中，导致通过纳米孔的离子电流减少。被捕获的DNA分子可以以用户控制的速度从纳米孔中被抬起。这种集成设备允许以亚纳米精度操纵附着在探头尖端的生物分子(DNA、RNA和蛋白质)，同时允许通过纳米孔设备测量生物分子。
In this work, we demonstrate that a tuning fork can be used as a force detecting sensor for manipulating DNA molecules and for controlling the DNA translocation rate through a nanopore. One prong of a tuning fork is glued with a probe tip which DNA molecules can be attached to. To control the motion and position of the tip, the tuning fork is fixed to a nanopositioning system which has sub-nanometer position control. A fluidic chamber is designed to fulfill many requirements for the experiment: for the access of a DNA-attached tip approaching to a nanopore, for housing a nanopore chip, and for measuring ionic current through a solid-state nanopore with a pair of electrodes. The location of a nanopore is first observed by transmission electron microscopy, and then is determined inside the liquid chambers with an optical microscope combined with local scanning the probe tip on the nanopore surface. When a DNA-immobilized tip approaches a membrane surface near a nanopore, free ends of the immobilized DNA strings can be pulled and trapped into the pore by an applied voltage across the nanopore chip, resulting in an ionic current reduction through the nanopore. The trapped DNA molecules can be lifted up from the nanopore at a user controlled speed. This integrated apparatus allows manipulation of biomolecules (DNA, RNA, and proteins) attached to a probe tip with sub-nanometer precision, and simultaneously allows measurement of the biomolecules by a nanopore device.