Nanoscale Ropes Produced at Berkeley Lab

Physicists in the United States managed to take another step forward in their struggle to develop self-assembling, nanoscale materials, when they developed a technique that forces polymers to create small rope-like structures on their own.

These wispy nanoscale rope approach the structural complexity of biological materials, which has been a major goal in science for decades. The achievement was made at the US Department of Energy’s (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab).

What researchers are trying to accomplish is develop a series of new materials that are just as intricate and have the same functionality as their natural counterparts, but which are at the same time strong and rugged enough to withstand the harsh conditions demanded by practical applications.

The Berkeley Lab team believes that the new self-assembling method they developed could in the near-future be used for a large variety of applications itself, such as for example creating drug-delivery particles, or creating scaffolds for other self-assembling materials.

Other potential uses include the development of molecular sensors, or the creation of sieve mechanisms of sorts, capable of performing the intricate task of separating individual molecules from each other.

By applying their new technique on special polymers called polypeptoids, the Berkeley Lab scientists were able to trigger the production of increasingly complex structures, ranging from sheets to stacks of sheets, and then ropes.

The latter were obtained when stacks of sheets rolled up into double helices, in a structure vaguely resembling the way DNA is set up. The nanoscale ropes that were produced in this fashion measured only 600 nanometers in width.

“This hierarchical self assembly is the hallmark of biological materials such as collagen, but designing synthetic structures that do this has been a major challenge,” explains scientist Ron Zuckermann.

The expert is the facility director of the Berkeley Lab Molecular Foundry Biological Nanostructures Facility (BNF). “Nature uses exact length and sequence to develop highly functional structures,” he goes on to say

“An antibody can recognize one form of a protein over another, and we’re trying to mimic this,” Zuckerman adds. Details of the team's achievements appeared in a recent issue of the esteemed Journal of the American Chemical Society (JACS).

Funding for the new study came in part from the Office of Naval Research (ONR).