Chad Mirkin and colleagues demonstrate that DNA-capped gold nanoparticles crystallize into Wulff polyhedra, that is, the equilibrium shapes that minimize the surface energy associated with the crystal facets, when cooled down slowly past the melting temperature of the DNA linkers, and that the polyhedra formed can be predicted from theoretical principles long used in atomic-scale crystallization. Mirkin and co-authors were able to form body-centered cubic (bcc), binary CsCl and face-centered cubic superlattices, of which the bcc and CsCl lattices resulted in micrometer-scale rhombic dodecahedron single crystals with the shape of the expected Wulff polyhedron. Interestingly, rhombic dodecahedrons were obtained across a range of nanoparticle sizes and DNA chain lengths. Mirkin and colleagues' findings imply that, because the surface energy of crystals of DNA-capped nanoparticles are dominated by the interactions between the DNA ligands, the surface energies of individual DNA-capped nanoparticles and their connectivity could be designed so as to obtain a macroscopic crystal shape.
ASJC Scopus subject areas
- 化学 (全般)