Electrically driving a DNA arm Most nanoelectromechanical systems are formed by etching inorganic materials such as silicon. Kopperger et al. improved the precision of such machines by synthesizing a 25-nm-long arm defined by a DNA six-helix bundle connected to a 55 nm-by-55 nm DNA origami plate via flexible single-stranded scaffold crossovers (see the Perspective by Hogberg). When placed in a cross-shaped electrophoretic chamber, the arms could be driven at angular frequencies of up to 25 Hz and positioned to within 2.5 nm. The arm could be used to transport fluorophores and inorganic nanoparticles. Science, this issue p. 296; see also p. 279 An electrically driven DNA origami arm can exert piconewton forces and transport fluorophores and nanoparticles. The use of dynamic, self-assembled DNA nanostructures in the context of nanorobotics requires fast and reliable actuation mechanisms. We therefore created a 55-nanometer–by–55-nanometer DNA-based molecular platform with an integrated robotic arm of length 25 nanometers, which can be extended to more than 400 nanometers and actuated with externally applied electrical fields. Precise, computer-controlled switching of the arm between arbitrary positions on the platform can be achieved within milliseconds, as demonstrated with single-pair Förster resonance energy transfer experiments and fluorescence microscopy. The arm can be used for electrically driven transport of molecules or nanoparticles over tens of nanometers, which is useful for the control of photonic and plasmonic processes. Application of piconewton forces by the robot arm is demonstrated in force-induced DNA duplex melting experiments.

中文翻译：

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一种由电场控制的自组装纳米机械臂

电驱动 DNA 臂 大多数纳米机电系统是通过蚀刻无机材料（如硅）形成的。科珀格等人。通过合成由 DNA 六螺旋束定义的 25 nm 长臂，通过灵活的单链支架交叉连接到 55 nm x 55 nm DNA 折纸板，提高了此类机器的精度（参见 Hogberg 的观点） . 当放置在十字形电泳室中时，臂可以以高达 25 Hz 的角频率驱动并定位在 2.5 nm 以内。该臂可用于运输荧光团和无机纳米颗粒。科学，这个问题 p。296; 另见第。279 电动 DNA 折纸臂可以施加皮牛顿力并传输荧光团和纳米颗粒。使用动态，纳米机器人背景下的自组装 DNA 纳米结构需要快速可靠的驱动机制。因此，我们创建了一个 55 纳米 x 55 纳米的基于 DNA 的分子平台，其中包含一个长度为 25 纳米的集成机械臂，该机械臂可以扩展到 400 纳米以上，并由外部施加的电场驱动。正如单对 Förster 共振能量转移实验和荧光显微镜所证明的那样，可以在几毫秒内实现平台上任意位置之间由计算机控制的精确臂切换。该臂可用于数十纳米以上的分子或纳米粒子的电驱动传输，这对于控制光子和等离子体过程很有用。