Illustration shows a programmable “molecular robot” — a sub-microscopic machine made of synthetic DNA that can move among different branches of a molecular track while carrying cargo. |
Scientists
have developed a programmable “molecular robot”
—a sub-microscopic
molecular machine made of synthetic DNA that moves between track
locations separated by 6 nm. The robot, a short strand of DNA, follows
instructions programmed into a set of fuel molecules determining its
destination. The report, which represents a step toward futuristic
nanomachines and nanofactories, appears in ACS’s Nano Letters (“A Programmable Molecular Robot”).
Andrew
Turberfield and colleagues at the Clarendon Laboratory at the
Univ. of Oxford point out that other scientists have developed
similar DNA-based robots, which move autonomously. Some of these use a
biped design and move by alternately attaching and detaching themselves
from anchor points along the DNA track, foot over foot, when fuel is
added. Scientists would like to program DNA robots to autonomously walk
in different directions to move in a programmable pattern, a key to
harnessing their potential as cargo-carrying molecular machines.
The
scientists describe an advance toward this goal—a robot that can be
programmed to choose among different branches of a molecular track,
rather than just move in a straight line. The key to this specialized
movement is a so-called “fuel hairpin,” a molecule that serves as both a
chemical energy source for propelling the robot along the track and as a
routing instruction. The instructions tell the robot which point is
should move to next, allowing the selection between the left or right
branches of a junction in the track, precisely controlling the route of
the robot—which could potentially allow the transport of
pharmaceuticals or other materials.