Carbon Nanotubes as AFM Tips: Measuring DNA Molecules at the Liquid/Solid Interface
Carbon Nanotubes as AFM Tips: Measuring DNA Molecules at the Liquid/Solid Interface
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DOI：
10.1002/(sici)1096-9918(199908)28:1
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发表时间：
1999-08
影响因子：
1.7
通讯作者：
Jun Li;A. Cassell;H. Dai
中科院分区：
文献类型：
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作者：
Jun Li;A. Cassell;H. Dai
缓冲溶液中软的和弱吸附的生物分子在缓冲溶液表面的高分辨率成像是研究中的一大挑战。在这里，我们证明了单个碳纳米管可以用来作为原子力显微镜(AFM)探测溶液中生物分子的尖端。将碳纳米管针尖的独特性质与最新发展的磁驱动振荡AFM技术相结合，我们能够获得分子水平的、高分辨率的DNA分子在溶液中吸附在云母表面的图像。单根纳米管尖端的长度和屈曲力可以直接从力-距离曲线中得到。这些测量表明，纳米管尖端具有很强的弹性，在被多余的力反复撞击表面后，它可以迅速恢复到全长。清晰的针尖几何结构为原子力显微镜成像提供了非凡的分辨率。碳纳米管作为原子力显微镜尖端的应用可能导致生物学研究的突破。
High-resolution imaging of soft and weakly adsorbed biomolecules on surfaces within buffer solutions presents a big challenge in research. Here we demonstrate that a single carbon nanotube could be used as a tip for probing biomolecules in solution using atomic force microscopy (AFM). Combining the unique properties of carbon nanotube tips with the newly developed magnetically driven oscillating AFM technique, we were able to obtain molecular-level, high-resolution images of DNA molecules adsorbed on the mica surface in solution. The length and the buckling force of the single nanotube tip can be derived directly from the force-distance curve. These measurements indicate that the nanotube tip is quite resilient, and it can quickly recover to its full length after repeatedly being crashed on the surface with excess force. The well-defined tip geometry provides extraordinary resolution in AFM imaging. The application of carbon nanotubes as AFM tips could lead to breakthroughs in biological studies.