A mathematical tool called a fast Fourier transform maps the structure in a way that reveals the 12-fold symmetry of the quasicrystal. The fast Fourier transform of the electron microscope image of the quasicrystal is shown on the left, while the transform of the simulated crystal is shown on the right. Image credit: Mirkin Research Group, Northwestern University, and Glotzer Group, University of Michigan.
Topics: Biology, DNA, Nanoengineering, Nanomaterials, Nanotechnology
ANN ARBOR—Nanoengineers have created a quasicrystal—a scientifically intriguing and technologically promising material structure—from nanoparticles using DNA, the molecule that encodes life.
The team, led by researchers at Northwestern University, the University of Michigan, and the Center for Cooperative Research in Biomaterials in San Sebastian, Spain, reports the results in Nature Materials.
Unlike ordinary crystals, which are defined by a repeating structure, the patterns in quasicrystals don’t repeat. Quasicrystals built from atoms can have exceptional properties—for example, absorbing heat and light differently, exhibiting unusual electronic properties such as conducting electricity without resistance, or their surfaces being very hard or very slippery.
Engineers studying nanoscale assembly often view nanoparticles as a kind of ‘designer atom,’ which provides a new level of control over synthetic materials. One of the challenges is directing particles to assemble into desired structures with useful qualities, and in building this first DNA-assembled quasicrystal, the team entered a new frontier in nanomaterial design.
“The existence of quasicrystals has been a puzzle for decades, and their discovery appropriately was awarded a Nobel Prize,” said Chad Mirkin, the George B. Rathmann Professor of Chemistry at Northwestern University and co-corresponding author of the study. “Although there are now several known examples, discovered in nature or through serendipitous routes, our research demystifies their formation and, more importantly, shows how we can harness the programmable nature of DNA to design and assemble quasicrystals deliberately.”
Nanoparticle quasicrystal constructed with DNA, Kate McAlpine, University of Michigan