Nanopore sensing at ultra-low concentrations using single-molecule dielectrophoretic trapping.
Nanopore sensing at ultra-low concentrations using single-molecule dielectrophoretic trapping.
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DOI：
10.1038/ncomms10217
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发表时间：
2016-01-06
影响因子：
16.6
通讯作者：
Edel JB
中科院分区：
文献类型：
--
作者：
Freedman KJ;Otto LM;Ivanov AP;Barik A;Oh SH;Edel JB
单分子技术正在开发中，通过产生大量的基因和蛋白质组数据，有望给医疗行业带来革命性的变化。一条非常有希望的途径是使用纳米孔传感器。然而，众所周知的复杂性是，检测和捕获主要是扩散受限的。考虑到纳米孔的捕获体积，通常比样品体积小108-1010倍，这个问题变得更加复杂。为了纠正这种不成比例的比例，我们展示了一种简单但强大的方法，该方法基于将单分子介电泳捕获与纳米孔传感相结合。我们表明，DNA可以从可控的、但通常要大得多的体积中捕获，并集中在金属纳米孔的尖端。这使得能够在低至5 fM的浓度下检测单分子，与现有方法相比，这大约是检测极限的103%，同时仍然保持了有效的吞吐量。纳米孔传感器在生物分子传感方面显示出巨大的潜力，尽管扩散控制的捕获会限制分析的速度。在这里，作者报告了一种将DNA浓缩到纳米孔尖端附近的介电泳法，将检测极限降低了三个数量级。
Single-molecule techniques are being developed with the exciting prospect of revolutionizing the healthcare industry by generating vast amounts of genetic and proteomic data. One exceptionally promising route is in the use of nanopore sensors. However, a well-known complexity is that detection and capture is predominantly diffusion limited. This problem is compounded when taking into account the capture volume of a nanopore, typically 108–1010 times smaller than the sample volume. To rectify this disproportionate ratio, we demonstrate a simple, yet powerful, method based on coupling single-molecule dielectrophoretic trapping to nanopore sensing. We show that DNA can be captured from a controllable, but typically much larger, volume and concentrated at the tip of a metallic nanopore. This enables the detection of single molecules at concentrations as low as 5 fM, which is approximately a 103 reduction in the limit of detection compared with existing methods, while still maintaining efficient throughput. Nanopore sensors have shown tremendous potential for biomolecule sensing, though the diffusion-controlled capture can limit the speed of analysis. Here, the authors report a dielectrophoretic method to concentrate DNA near the tip of a nanopore, reducing the limit of detection by three orders of magnitude.