A single DNA molecule nanomotor

Nanomotors consisting of single protein molecules are abundant in living systems. Here we report a nanomotor made of a single DNA molecule. The DNA nanomotor can adopt two distinct conformations, intramolecular tetraplex and intermolecular duplex. The nanomotor switches between the two conformations through alternating DNA hybridization and strand exchange reactions, which enables the nanomotor to perform an inchworm like extending-shrinking motion, When the single molecule nanomotor is loaded with two organic molecules, a fluorophore and a quencher, the motion can be viewed in real time by monitoring the fluorescent signal. The DNA nanomotor functions efficiently both in solution and on nanoparticle surfaces. Its simple yet stable structure, convenient operation, and high efficiency may make the DNA nanomotor practically useful for powering nanosystems in future applications.