The First DNA-Assembled Quasicrystal

Saturday - December 30 2023, 03:55 UTC - 10 months ago

Nanoengineers have created a quasicrystal from nanoparticles using DNA, exhibiting many interesting properties. A team from Northwestern University, the University of Michigan, and the Center for Cooperative Research in Biomaterials in San Sebastian, Spain, reports the results in Nature Materials. DNA is used to program the particles to assemble into a quasicrystal, completely demystifying the formation of quasicrystals and opening a new frontier in nanomaterial design.

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 are 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 with 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." .

Mirkin’s group is known for using DNA as a designer glue to engineer the formation of colloidal crystals made of nanoparticles, and the group of Luis Liz-Marzán, the Ikerbasque Professor at the Spanish Center for Cooperative Research in Biomaterials, could produce nanoparticles that might form quasicrystals under the right conditions.

The team focused on bipyramidal shapes—basically two pyramids stuck together at their bases. Liz-Marzán’s group tried different numbers of sides as well as squashing and stretching the shapes. Wenjie Zhou and Haixin Lin, doctoral students in chemistry at Northwestern at the time of the work, used DNA strands encoded to recognize one another to program the particles to assemble into a quasicrystal.

Independently, the group of Sharon Glotzer, the Anthony C. Lembke Chair of Chemical Engineering at U-M, had been simulating bipyramids with different numbers of sides. Yein Lim and Sangmin Lee, doctoral students in chemical engineering at U-M, found that decahedra—10-sided pentagonal bipyramids—would form a quasicrystal under certain conditions, and with the right relative dimensions.

In 2009, Glotzer’s team had predicted the first layered nanoparticle quasicrystal, not from bipyramids but from tetrahedra—single pyramids with four triangular sides like a D4 die. Because five tetrahedra can nearlty pack together, they form layers that might stack in a quasicrystal pattern.