Credit: Thomas
Edwardson
(January 7, 2016) New
technique could facilitate use of gold nanoparticles in electronic, medical
applications
Gold nanoparticles have unusual optical, electronic and
chemical properties, which scientists are seeking to put to use in a range of
new technologies, from nanoelectronics to cancer treatments.
Gold nanoparticles have unusual optical, electronic and
chemical properties, which scientists are seeking to put to use in a range of
new technologies, from nanoelectronics to cancer treatments.
Some of the most interesting properties of nanoparticles
emerge when they are brought close together – either in clusters of just a few
particles or in crystals made up of millions of them. Yet particles that are just millionths of an
inch in size are too small to be manipulated by conventional lab tools, so a
major challenge has been finding ways to assemble these bits of gold while
controlling the three-dimensional shape of their arrangement.
One approach that researchers have developed has been to use
tiny structures made from synthetic strands of DNA to help organize
nanoparticles. Since DNA strands are programmed to pair with other strands in
certain patterns, scientists have attached individual strands of DNA to gold
particle surfaces to create a variety of assemblies. But these hybrid gold-DNA
nanostructures are intricate and expensive to generate, limiting their
potential for use in practical materials. The process is similar, in a sense,
to producing books by hand.
Enter the nanoparticle equivalent of the printing press.
It’s efficient, re-usable and carries more information than previously
possible. In results reported online in Nature Chemistry, researchers from
McGill’s Department of Chemistry outline a procedure for making a DNA structure
with a specific pattern of strands coming out of it; at the end of each strand
is a chemical “sticky patch.” When a
gold nanoparticle is brought into contact to the DNA nanostructure, it sticks
to the patches. The scientists then dissolve the assembly in distilled water,
separating the DNA nanostructure into its component strands and leaving behind
the DNA imprint on the gold nanoparticle. (See illustration.)