A new method uses DNA origami to turn one-dimensional nanomaterials into two dimensions.
Their breakthrough, published in the latest issue of Nature Nanotechnology, offers the potential to enhance fiber optics and electronic devices by reducing their size and increasing their speed.
“We can now take linear nanomaterials and direct how they are organized in two dimensions, using a DNA origami platform to create any number of shapes,” explains senior author Nadrian Seeman, chemistry professor at New York University, who founded and developed the field of DNA nanotechnology three decades ago.
Seeman’s collaborator, Sally Gras, an associate professor at the University of Melbourne, says, “We brought together two of life’s building blocks, DNA and protein, in an exciting new way. We are growing protein fibers within a DNA origami structure.”
DNA origami employs approximately two hundred short DNA strands to direct longer strands in forming specific shapes. In their work, the scientists sought to create, and then manipulate the shape of, amyloid fibrils—rods of aggregated proteins, or peptides, that match the strength of spider’s silk.
To do so, they engineered a collection of 20 DNA double helices to form a nanotube big enough (15 to 20 nanometers—just over one-billionth of a meter—in diameter) to house the fibrils.
The platform builds the fibrils by combining the properties of the nanotube with a synthetic peptide fragment that is placed inside the cylinder. The resulting fibril-filled nanotubes can then be organized into two-dimensional structures through a series of DNA-DNA hybridization interactions.
“Fibrils are remarkably strong and, as such, are a good barometer for this method’s ability to form two-dimensional structures,” observes Seeman. “If we can manipulate the orientations of fibrils, we can do the same with other linear materials in the future.”
Seeman points to the promise of creating two-dimensional shapes on the nanoscale.
“If we can make smaller and stronger materials in electronics and photonics, we have the potential to improve consumer products,” Seeman says.
“For instance, when components are smaller, it means the signals they transmit don’t need to go as far, which increases their operating speed. That’s why small is so exciting—you can make better structures on the tiniest chemical scales.”
The National Institute of General Medical Sciences, part of the National Institutes of Health; the National Science Foundation; the Army Research Office; the Office of Naval Research; an Australian Nanotechnology Network Overseas Travel Fellowship; a Melbourne Abroad Traveling Scholarship; the Bio21 Institute and Particulate Fluids Processing Centre supported the research.
The work partially took place at the Center for Functional Nanomaterials, Brookhaven National Laboratory, which is supported by the US Department of Energy, Office of Basic Energy Sciences.