Letter abstract
Nature Materials 8, 52 - 55 (2009)
Published online: 30 November 2008 | doi:10.1038/nmat2338
Subject Category: Biological materials
Probing interfacial equilibration in microsphere crystals formed by DNA-directed assembly
Anthony J. Kim1,3, Raynaldo Scarlett1,3, Paul L. Biancaniello2, Talid Sinno1 & John C. Crocker1
DNA is the premier material for directing nanoscale self-assembly, having been used to produce many complex forms1, 2, 3, 4. Recently, DNA has been used to direct colloids5, 6 and nanoparticles7, 8 into novel crystalline structures, providing a potential route to fabricating meta-materials9 with unique optical properties. Although theory10, 11, 12 has sought the crystal phases that minimize total free energy, kinetic barriers13 remain essentially unstudied. Here we study interfacial equilibration in a DNA-directed microsphere self-assembly system5, 6, 14 and carry out corresponding detailed simulations. We introduce a single-nucleotide difference in the DNA strands on two mixed microsphere species, which generates a free-energy penalty5, 15, 16 for inserting 'impurity' spheres into a 'host' sphere crystal, resulting in a reproducible segregation coefficient. Comparison with simulation reveals that, under our experimental conditions, particles can equilibrate only with a few nearest neighbours before burial by the growth front, posing a potential impediment to the growth of complex structures.
- Department of Chemical and Biomolecular Engineering, The University of Pennsylvania, 220 S. 33rd St. Philadelphia, Pennsylvania 19104, USA
- Department of Physics and Astronomy, The University of Pennsylvania, 209 S. 33rd St. Philadelphia, Pennsylvania 19104, USA
- These authors contributed equally to this work
Correspondence to: John C. Crocker1 e-mail: jcrocker@seas.upenn.edu
