Nature Nanotechnology ：利用纳米通道技术首次精确检测DNA
来自Purdue大学Birck纳米技术中心的科学家最近展示了如何利用“纳米小孔通道”来快速精确的检测特定DNA序列，这一技术能用于医药、环境监控及国土安全等诸多领域。
纳米通道直径约为10到20纳米之间，长度为数百纳米，它们是由内部结合了单链DNA的硅质通道构成的。电子和计算机工程教授Rashid Bashir表示，之前其它的研究小组已经制造出过这一类通道，但是Purdue小组是世界首个将特定DNA单链结合到这种硅通道内的小组，然后科学家就可以用它们探测液体中的DNA分子了。
详细结果发表在了本周出版的《自然-纳米科技》（Nature Nanotechnology）上。作者包括博士后Samir Iqbal，助理教授Demir Akin以及Bashir。
每个通道都在一个很薄的硅膜上制造，然后放入含有DNA的液体中。由于DNA是带负电的，跨膜施加一个电压就会造成遗传物质穿过通道。科学家发现那些和通道内部附着的DNA完全匹配的DNA能更快速的移动，并且穿过孔的数量也更大。
Bashir说：“我们能通过测量通道的电流大小来确定特定DNA链的移动。本质上而言，可以利用特殊的信号脉冲作为特定DNA移动的结果。”DNA是由4种不同的核苷酸基构成的，这些基之间两两结合，就形成了双链螺旋结构。
Iqbal说：“当液体中的DNA能和通道内的完美匹配时，电流脉冲要比哪怕只有一个基不匹配时都要短促得多。”这一技术能快速探测DNA分子，并且不需要任何标记分子，它有望用于很多DNA检测领域。
原始出处：http://www.physorg.com/news95006759.html
部分英文原文：
Nature Nanotechnology 2, 243 - 248 (2007)
Published online: 1 April 2007 | doi:10.1038/nnano.2007.78
Subject Categories: Nanobiotechnology | Nanosensors and other devices
Solid-state nanopore channels with DNA selectivity
Samir M. Iqbal1, Demir Akin1,2 & Rashid Bashir1,2
Abstract
Solid-state nanopores have emerged as possible candidates for next-generation DNA sequencing devices. In such a device, the DNA sequence would be determined by measuring how the forces on the DNA molecules, and also the ion currents through the nanopore, change as the molecules pass through the nanopore. Unlike their biological counterparts, solid-state nanopores have the advantage that they can withstand a wide range of analyte solutions and environments. Here we report solid-state nanopore channels that are selective towards single-stranded DNA (ssDNA). Nanopores functionalized with a 'probe' of hair-pin loop DNA can, under an applied electrical field, selectively transport short lengths of 'target' ssDNA that are complementary to the probe. Even a single base mismatch between the probe and the target results in longer translocation pulses and a significantly reduced number of translocation events. Our single-molecule measurements allow us to measure separately the molecular flux and the pulse duration, providing a tool to gain fundamental insight into the channel–molecule interactions. The results can be explained in the conceptual framework of diffusive molecular transport with particle–channel interactions.
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- Birck Nanotechnology Center, School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana 47907, USA
Correspondence to: Rashid Bashir1,2 e-mail: bashir@purdue.edu
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