Improved Kelvin probe force microscopy for imaging individual DNA molecules on insulating surfaces
Improved Kelvin probe force microscopy for imaging individual DNA molecules on insulating surfaces
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DOI：
10.1063/1.3512867
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发表时间：
2010-11-15
影响因子：
4
通讯作者：
Hoogenboom, Bart W.
中科院分区：
文献类型：
--
作者：
Leung, Carl;Maradan, Dario;Hoogenboom, Bart W.
静电力和电位是确定生物分子之间相互作用的关键。我们最近使用开尔文探针力显微镜（KPFM）对硅表面上核酸分子的形貌和静电表面电位进行了成像。在这里，我们展示了云母等绝缘表面上的 KPFM 成像，它可以获取 DNA 的配置，即其结构在溶液中的投影。特别是，我们应用双频模式来最小化获取开尔文探针信号的尖端与样品的距离，并使用悬臂的基本共振来确定表面电势及其第一泛音来检测形貌。 (C) 2010 年美国物理研究所。 [号码：10.1063/1.3512867]
Electrostatic forces and potentials are keys in determining the interactions between biomolecules. We have recently imaged the topography and electrostatic surface potential of nucleic acid molecules on silicon surfaces using Kelvin probe force microscopy (KPFM). Here, we demonstrate KPFM imaging on insulating surfaces like mica, which provides access to configurations of DNA that are projections of its structure in solution. In particular, we apply dual-frequency mode to minimize the tip-sample distance at which the Kelvin probe signal is acquired and use the fundamental resonance of the cantilever to determine surface potential and its first overtone to detect the topography. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3512867]