Real-time magnetic actuation of DNA nanodevices via modular integration with stiff micro-levers

Stephanie Lauback,Maxim Armstrong,Alexander E Marras,Carlos E Castro,Ratnasingham Sooryakumar,Kara R Mattioli,Thomas P Rudibaugh

doi:10.1038/s41467-018-03601-5

Abstract

DNA nanotechnology has enabled complex nanodevices, but the ability to directly manipulate systems with fast response times remains a key challenge. Current methods of actuation are relatively slow and only direct devices into one or two target configurations. Here we report an approach to control DNA origami assemblies via externally applied magnetic fields using a low-cost platform that enables actuation into many distinct configurations with sub-second response times. The nanodevices in these assemblies are manipulated via mechanically stiff micron-scale lever arms, which rigidly couple movement of a micron size magnetic bead to reconfiguration of the nanodevice while also enabling direct visualization of the conformation. We demonstrate control of three assemblies—a rod, rotor, and hinge—at frequencies up to several Hz and the ability to actuate into many conformations. This level of spatiotemporal control over DNA devices can serve as a foundation for real-time manipulation of molecular and atomic systems.

Highlights

DNA nanotechnology has enabled complex nanodevices, but the ability to directly manipulate systems with fast response times remains a key challenge
The nanorotor consists of three components: a base platform, a 56 helix rotor arm, and a flexible pivot that connects the rotor to the base platform
The nano-hinge designed in this study is constructed from two ~30 nm long arms, each containing 36 double-stranded DNA helices, which are connected at one edge by eight single-stranded DNA (ssDNA) linker connections

Summary

Introduction

DNA nanotechnology has enabled complex nanodevices, but the ability to directly manipulate systems with fast response times remains a key challenge. We report an approach to control DNA origami assemblies via externally applied magnetic fields using a low-cost platform that enables actuation into many distinct configurations with sub-second response times The nanodevices in these assemblies are manipulated via mechanically stiff micron-scale lever arms, which rigidly couple movement of a micron size magnetic bead to reconfiguration of the nanodevice while enabling direct visualization of the conformation. Other recent developments have introduced changing buffer conditions such as light or ion concentrations to reconfigure structures[24], and recent studies demonstrated actuation times on the scale of ~10 s via temperature or pH changes[19,25] These actuation approaches generally release or facilitate local interactions, and control is limited to stabilizing one or two pre-programmed states as opposed to directly and continuously manipulating the device into a specific configuration with an applied force. Our approach allows specific control over the angular conformation with resolution of ±8°, continuous rotational motion up to 2 Hz, and the capability of applying up to 80 pN∙nm of torque

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Conclusion