Krissanaprasit Abhichart, Madsen Mikael, Knudsen Jakob Bach, Gudnason Daniel, Surareungchai Werasak, Birkedal Victoria, Gothelf Kurt Vesterager
School of Bioresources and Technology, King Mongkut's University of Technology Thonburi , Bangkhuntien Campus, Bangkok 10150, Thailand.
ACS Nano. 2016 Feb 23;10(2):2243-50. doi: 10.1021/acsnano.5b06894. Epub 2016 Jan 20.
DNA nanotechnology offers precise geometrical control of the positioning of materials, and it is increasingly also being used in the development of nanomechanical devices. Here we describe the development of a nanomechanical device that allows switching of the position of a single-molecule conjugated polymer. The polymer is functionalized with short single-stranded (ss) DNA strands that extend from the backbone of the polymer and serve as handles. The DNA polymer conjugate can be aligned on DNA origami in three well-defined geometries (straight line, left-turned, and right-turned pattern) by DNA hybridization directed by single-stranded guiding strands and ssDNA tracks extending from the origami surface and polymer handle. We demonstrate switching of a conjugated organic polymer conformation between left- and right-turned conformations of the polymer on DNA origami based on toehold-mediated strand displacement. The switching is observed by atomic force microscopy and by Förster resonance energy transfer between the polymer and two different organic dyes positioned in close proximity to the respective patterns. Using this method, the polymer conformation can be switched six times successively. This controlled nanomechanical switching of conjugated organic polymer conformation demonstrates unique control of the shape of a single polymer molecule, and it may constitute a new component for the development of reconfigurable nanophotonic and nanoelectronic devices.
DNA纳米技术能够对材料的定位进行精确的几何控制，并且它在纳米机械设备的开发中也越来越多地得到应用。在此，我们描述了一种纳米机械设备的开发，该设备能够实现单分子共轭聚合物位置的切换。聚合物通过从聚合物主链延伸出的短单链（ss）DNA链进行功能化修饰，这些单链DNA链起到手柄的作用。通过由单链引导链以及从折纸表面和聚合物手柄延伸出的ssDNA轨道所引导的DNA杂交，DNA - 聚合物共轭物能够以三种明确的几何形状（直线、左旋和右旋模式）排列在DNA折纸结构上。我们展示了基于踏脚介导的链置换，共轭有机聚合物在DNA折纸上从左旋构象到右旋构象之间的构象切换。通过原子力显微镜以及聚合物与紧邻各自图案定位的两种不同有机染料之间的Förster共振能量转移来观察这种切换。使用这种方法，聚合物构象可以连续切换六次。这种共轭有机聚合物构象的可控纳米机械切换展示了对单个聚合物分子形状的独特控制，并且它可能构成可重构纳米光子和纳米电子器件开发的一个新组件。
