Single-Molecule AFM Characterization of Individual Chemically Tagged DNA Tetrahedra
Single-Molecule AFM Characterization of Individual Chemically Tagged DNA Tetrahedra
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DOI：
10.1021/nn201705p
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发表时间：
2011-09-01
期刊：
影响因子：
17.1
通讯作者：
Ebner, Andreas
中科院分区：
文献类型：
--
作者：
Leitner, Michael;Mitchell, Nick;Ebner, Andreas
单分子表征对于确定自下而上的DNA纳米结构的结构和功能特性至关重要。在这里，我们使用三种原子力显微镜（AFM）技术来检查用小化学标签功能增强的四面体形状的DNA纳米结构。为了在生物传感和生物物理学中应用于生物分子固定化，四面体具有三个二硫化物修饰的顶点，以实现对金表面的定向附着。剩下的角落携带一个单一的生物配体，可以捕获和呈现单个的货物生物分子，以确定的横向纳米级间距。高分辨率AFM地形成像证实了定向表面附着以及单个受体分子与暴露的生物配体的高效结合。在单分子水平上，利用分子识别力谱，利用带有拴系分子受体的AFM悬臂尖端，获得了对结合行为的深入了解。最后，同时的地形成像和识别成像显示了单个四面体上特异性受体-配体相互作用。综上所述，AFM表征验证了合理设计的DNA纳米结构具有在生物传感、生物物理学和细胞生物学中作为有价值的固定剂的特性。
Single-molecule characterization is essential for ascertaining the structural and functional properties of bottom-up DNA nanostructures. Here we enlist three atomic force microscopy (AFM) techniques to examine tetrahedron-shaped DNA nanostructures that are functionally enhanced with small chemical tags. In line with their application for biomolecule immobilization in biosensing and biophysics, the tetrahedra feature three disulfide-modified vertices to achieve directed attachment to gold surfaces. The remaining corner carries a single bioligand that can capture and present individual cargo biomolecules at defined lateral nanoscale spacing. High-resolution AFM topographic imaging confirmed the directional surface attachment as well as the highly effective binding of individual receptor molecules to the exposed bioligands. Insight into the binding behavior at the single-molecule level was gained using molecular recognition force spectroscopy using an AFM cantilever tip with a tethered molecular receptor. Finally, simultaneous topographic and recognition imaging demonstrated the specific receptor-ligand interactions on Individual tetrahedra. In summary, AFM characterization verified that the rationally designed DNA nanostructures feature characteristics to serve as valuable immobilization agents in biosensing, biophysics, and cell biology.