Controlling nanopore size, shape and stability
Controlling nanopore size, shape and stability
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DOI：
10.1088/0957-4484/21/11/115304
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发表时间：
2010-03-19
期刊：
影响因子：
3.5
通讯作者：
Dekker, Nynke H.
中科院分区：
文献类型：
--
作者：
van den Hout, Michiel;Hall, Adam R.;Dekker, Nynke H.
固态纳米孔被认为是研究生物聚合物如DNA和RNA的有前途的工具，这主要是由于它们在尺寸上的灵活性，在设备集成和鲁棒性方面的潜力。在这里，我们表明，精确的形状的小纳米孔（类似于5纳米直径的20纳米SiN膜）可以通过使用不同尺寸的透射电子显微镜（TEM）光束控制。然而，当这些小纳米孔中的一些浸入水溶液中时，观察到它们的电阻随时间降低。通过比较不同形状的纳米孔使用（扫描）TEM浸泡在水溶液中之前和之后，我们证明了小纳米孔的稳定性与它们的三维几何形状有关，这取决于孔制造过程中采用的TEM光束尺寸。使用与预期纳米孔直径大致相同尺寸的TEM束尺寸获得最佳稳定性。此外，我们表明，热氧化可以作为一种手段，独立控制纳米孔径TEM制造。这些观察结果为在核酸和小蛋白质的尺度上制造稳定的固态纳米孔提供了关键指导。
Solid-state nanopores are considered a promising tool for the study of biological polymers such as DNA and RNA, due largely to their flexibility in size, potential in device integration and robustness. Here, we show that the precise shape of small nanopores (similar to 5 nm diameter in 20 nm SiN membranes) can be controlled by using transmission electron microscope (TEM) beams of different sizes. However, when some of these small nanopores are immersed in an aqueous solution, their resistance is observed to decrease over time. By comparing nanopores of different shapes using (scanning) TEM both before and after immersion in aqueous solution, we demonstrate that the stability of small nanopores is related to their three-dimensional geometry, which depends on the TEM beam size employed during pore fabrication. Optimal stability is obtained using a TEM beam size of approximately the same size as the intended nanopore diameter. In addition, we show that thermal oxidation can serve as a means to independently control nanopore size following TEM fabrication. These observations provide key guidelines for the fabrication of stable solid-state nanopores on the scale of nucleic acids and small proteins.