Enzyme-driven Nanorobots Walking Along Predesigned Tracks on the DNA Origami for Cargo Transport and Catalysis

In molecular engineering, designing and synthesizing molecular machines with capable of performing complex tasks, remains a formidable challenge. DNA is an excellent candidate for building molecular robots because it is highly programmable. Here, we present an artificial nanorobot, in which a DNA cube serves as the inert ‘body’, and nucleic acid catalysts based on an enzymatic nicking reaction act as the ‘legs’ for walking. The nanorobot can execute a series of actions, such as ‘start’, ‘turn’, and ‘stop’ when it walks along a predefined track. Its performance could be confirmed and monitored by using an atomic force microscope (AFM) and fluorescence spectroscopy. Inspired by biological machines, we artificially designed a series of specialized tasks that combined walking with control of cargo transport and catalysis. Real-time fluorescence kinetics curves provide monitoring signals for cargo transport and catalytic processes. Our work can enrich the toolbox of DNA machinery and has great potential for engineering molecular nanofactories.