Oh, my stars and hexagons! DNA code shapes gold nanoparticles

Aug 08, 2012
University of Illinois chemists found that DNA can shape gold nanoparticle growth similarly to the way it shapes protein synthesis, with different letters of the genetic code producing gold circles, stars and hexagons. Graphic by Li Huey Tan, Zidong Wang and Yi Lu

(Phys.org) -- DNA holds the genetic code for all sorts of biological molecules and traits. But University of Illinois researchers have found that DNA's code can similarly shape metallic structures.

The team found that can direct the shape of gold nanoparticles – tiny gold crystals that have many applications in medicine, electronics and catalysis. Led by Yi Lu, the Schenck Professor of Chemistry at the U. of I., the team published its surprising findings in the journal Angewandte Chemie.

"DNA-encoded nanoparticle synthesis can provide us a facile but novel way to produce nanoparticles with predictable shape and properties," Lu said. "Such a discovery has potential impacts in bio-nanotechnology and applications in our everyday lives such as catalysis, sensing, imaging and medicine."

Gold nanoparticles have wide applications in both biology and materials science thanks to their unique physicochemical properties. Properties of a gold nanoparticle are largely determined by its shape and size, so it is critical to be able to tailor the properties of a nanoparticle for a specific application.

"We wondered whether different combinations of DNA sequences could constitute 'genetic codes' to direct the nanomaterial synthesis in a way similar to their direction of protein synthesis," said Zidong Wang, a recent graduate of Lu's group and the first author of the paper.

Gold nanoparticles follow 'genetic code'

are made by sewing tiny gold seeds in a solution of gold salt. Particles grow as gold in the salt solution deposits onto the seeds. Lu's group incubated the gold seeds with short segments of DNA before adding the salt solution, causing the particles to grow into various shapes determined by the genetic code of the DNA.

The DNA alphabet comprises four letters: A, T, G and C. The term refers to the sequence of these letters, called bases. The four bases and their combinations can bind differently with facets of gold nanoseeds and direct the nanoseeds' growth pathways, resulting in different shapes.

In their experiments, the researchers found that strands of repeating A's produced rough, round particles; T's, stars; C's, round, flat discs; G's, hexagons. Then the group tested DNA strands that were a combination of two bases, for example, 10 T's and 20 A's. They found that many of the bases compete with each other resulting in intermediate shapes, although A dominates over T.

Next, the researchers plan to investigate exactly how DNA codes direct nanoparticle growth. They also plan to apply their method to synthesize other types of nanomaterials with novel applications.

Explore further: Innovative strategy to facilitate organ repair

More information: The paper, "Discovery of the DNA 'Genetic Code' for Abiological Gold Nanoparticle Morphologies," is available online. dx.doi.org/10.1002/anie.201203716

Related Stories

Metal sheets with DNA framework may enable nanocircuits

May 20, 2009

(PhysOrg.com) -- Using DNA not as a genetic material but as a structural support, Cornell researchers have created thin sheets of gold nanoparticles held together by strands of DNA. The work could prove useful ...

Building crystalline materials from nanoparticles and DNA

Oct 13, 2011

Nature is a master builder. Using a bottom-up approach, nature takes tiny atoms and, through chemical bonding, makes crystalline materials, like diamonds, silicon and even table salt. In all of them, the properties of the ...

Recommended for you

Innovative strategy to facilitate organ repair

Apr 18, 2014

A significant breakthrough could revolutionize surgical practice and regenerative medicine. A team led by Ludwik Leibler from the Laboratoire Matière Molle et Chimie (CNRS/ESPCI Paris Tech) and Didier Letourneur ...

Physicists create new nanoparticle for cancer therapy

Apr 16, 2014

A University of Texas at Arlington physicist working to create a luminescent nanoparticle to use in security-related radiation detection may have instead happened upon an advance in photodynamic cancer therapy.

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Telekinetic
not rated yet Aug 08, 2012
"Gold nanoparticles are made by sewing tiny gold seeds in a solution of gold salt."- article
That would be "sowing" tiny gold seeds. This finding causes me to wonder about the crystalline nature of DNA's structure, and how living organisms may have growth patterns akin to crystals.

More news stories

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...