DNA Based Nanomachines Developed using Single-Molecule Fluorescence and Operated using Computer Controlled Microfluidics

Eyal Nir, Chemistry, Ben Gurion University, Beer Sheva, Israel

We combined computer controlled microfluidics device and single-molecule TIRF and FRET spectroscopy to operate and study DNA based bipedal walker that strides on a DNA origami. The highly reliable walker preformed 36 consecutive steps, crossing a distance of 400 nm, with more than 99% yield per chemical reaction, which is a record distance and yield for artificial molecular motors.

The 16 channels microfluidics device provided the fuel and antifuel DNA strands required for the operation of the motor. A computer automatically controlled the microfluidics device and dictates the motor direction and speed, and removed the excess strands and waste products which made the record high operational yield possible.

The motor progress and position along the track was monitored by single-molecule FRET, and the microfluidics enabled preforming non-equilibrium FRET based kinetic measurements of the walker’s leg-lifting and leg-placing reactions with sub-second and nanometer resolutions, enabling resolving the reactions mechanisms.

This novel combination of DNA nanotechnology, microfluidics technology and single-molecule fluorescence spectroscopy holds a great promise for future computer control molecular machines.