Nature:分子納米機器人新突破

專題：Nature系列

來自南京大學和美國紐約大學的兩個小組報告了在研製能夠在分子尺度上做有用工作的可編程「納米機器人」方面所取得的顯著進展。

較大的機器人需要一個記憶裝置來存放指令，但這些小機器人卻是從它們環境中的分子接受指令的。

兩個體系都利用了最近幾年開發出的兩個重要DNA模塊：一個是沿DNA軌道行走的DNA「行走者」；另一個是「DNA摺紙」。

Gu等人演示了一個微型組裝線，它能通過將三種不同類型的金納米顆粒結合起來製造8種可能的複合物。一個「DNA摺紙」磚是這個生產線的框架和軌道，一個有三隻手、四隻腳的「DNA行走者」沿這個軌道行走，生成最終產品，其方式是：在它通過三種不同的載貨DNA機器時將所收集的金納米顆粒連接起來。Lund等人演示的納米機器人是蜘蛛形狀的DNA「行走者」，它們能在一個二維「DNA摺紙」景觀中感應和改動基質分子軌道，這個景觀通過編程來讓「行走者」執行諸如「開始」、「跟隨」、「轉彎」和「停止」等動作。（生物谷Bioon.com）

生物谷推薦原文出處：

Nature doi:10.1038/nature09026

A proximity-based programmable DNA nanoscale assembly line
Hongzhou Gu1, Jie Chao2, Shou-Jun Xiao2 & Nadrian C. Seeman1

1 Department of Chemistry, New York University, New York, New York 10003, USA
2 State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing 210093, China

Our ability to synthesize nanometre-scale chemical species, such as nanoparticles with desired shapes and compositions, offers the exciting prospect of generating new functional materials and devices by combining them in a controlled fashion into larger structures. Self-assembly can achieve this task efficiently, but may be subject to thermodynamic and kinetic limitations: reactants, intermediates and products may collide with each other throughout the assembly time course to produce non-target species instead of target species. An alternative approach to nanoscale assembly uses information-containing molecules such as DNA1 to control interactions and thereby minimize unwanted cross-talk between different components. In principle, this method should allow the stepwise and programmed construction of target products by linking individually selected nanoscale components—much as an automobile is built on an assembly line. Here we demonstrate that a nanoscale assembly line can be realized by the judicious combination of three known DNA-based modules: a DNA origami2 tile that provides a framework and track for the assembly process, cassettes containing three independently controlled two-state DNA machines that serve as programmable cargo-donating devices3, 4 and are attached4, 5 in series to the tile, and a DNA walker that can move on the track from device to device and collect cargo. As the walker traverses the pathway prescribed by the origami tile track, it sequentially encounters the three DNA devices, each of which can be independently switched between an 『ON』 state, allowing its cargo to be transferred to the walker, and an 『OFF』 state, in which no transfer occurs. We use three different types of gold nanoparticle species as cargo and show that the experimental system does indeed allow the controlled fabrication of the eight different products that can be obtained with three two-state devices.