UPTON, NY-Scientists at the U.S. Department of Energy's Brookhaven National Laboratory have developed a general approach for combining different types of nanoparticles to produce large-scale composite materials. The technique, described in a paper published online by Nature Nanotechnology on October 20, 2013, opens many opportunities for mixing and matching particles with different magnetic, optical, or chemical properties to form new, multifunctional materials or materials with enhanced performance for a wide range of potential applications.
The approach takes advantage of the attractive pairing of complementary strands of synthetic DNA-based on the molecule that carries the genetic code in its sequence of matched bases known by the letters A, T, G, and C. After coating the nanoparticles with a chemically standardized "construction platform" and adding extender molecules to which DNA can easily bind, the scientists attach complementary lab-designed DNA strands to the two different kinds of nanoparticles they want to link up. The natural pairing of the matching strands then "self-assembles" the particles into a three-dimensional array consisting of billions of particles. Varying the length of the DNA linkers, their surface density on particles, and other factors gives scientists the ability to control and optimize different types of newly formed materials and their properties.
"Our study demonstrates that DNA-driven assembly methods enable the by-design creation of large-scale 'superlattice' nanocomposites from a broad range of nanocomponents now available-including magnetic, catalytic, and fluorescent nanoparticles," said Brookhaven physicist Oleg Gang, who led the research at the Lab's Center for Functional Nanomaterials (CFN). "This advance builds on our previous work with simpler systems, where we demonstrated that pairing nanoparticles with different functions can affect the individual particles' performance, and it offers routes f
|Contact: Karen McNulty Walsh|
DOE/Brookhaven National Laboratory