DNA, the molecule that carries life’s blueprint, is being used to control the size of nanoparticles and the speed at which they form. Learning how to tailor their assembly could lead to the creation of nanoparticles for more efficient energy generation, data storage and drug delivery systems, among other uses. Mathew Maye, a chemist in Brookhaven National Laboratory's new Center for Functional Nanomaterials, presented the findings yesterday at the 234th National Meeting of the American Chemical Society in Boston. Mathew Maye, a chemist in Brookhaven National Laboratory's new Center for Functional Nanomaterials, and colleagues have demonstrated how to control the self-assembly of gold nanoparticles using various types of DNA. "We can synthesize nanoparticles with very well-controlled optical, catalytic, and magnetic properties," Maye said. "They are usually free-flowing in solution, but for use in a functional device, they have to be organized in three dimensions, or on surfaces, in a well-controlled manner. That's where self-assembly comes into play. We want the particles to do the work themselves." Using optical measurements, transmission electron microscopy, and x-ray scattering at Brookhaven’s National Synchrotron Light Source, Maye and his colleagues have shown how to control the self-assembly of gold nanoparticles with the help of various types of DNA. Their technique takes advantage of DNA's natural tendency to pair up components called bases, known by the code letters A, T, G and C. The synthetic DNA used in the laboratory is capped onto individual gold nanoparticles and customized to recognize and bind to complementary DNA located on other particles. This process forms clusters, or aggregates, which contain multiple particles. The research group previously used rigid, double-stranded DNA to speed up and slow down the speed of nanoparticle assembly. Most recently, they also perfected a method for regulating the size of the resulting particle clusters by incorporating multiple types of DNA strands. "Self-assembly is really a frontier of nanoscience," Maye said. "Learning how to take a solution of nanomaterials and end up with a functional device is going to be a great achievement." This research was funded by the Office of Basic Energy Sciences within the US Department of Energy's Office of Science. For more information, visit: www.bnl.gov