Of Gold, Silver, and Diamonds

Science  21 Apr 2006:
Vol. 312, Issue 5772, pp. 333e
DOI: 10.1126/science.312.5772.333e

Nanoparticles can be assembled into a variety of crystalline lattices that are close-packed in nature, but more open structures reminiscent of the diamond lattice are harder to form. Kalsin et al. (p. 420, published online 23 February; see the Perspective by Velev) exploit electrostatic effects to assemble gold and silver nanoparticles, of the same size but coated with oppositely charged monolayers, into the diamond-like sphalerite lattice. Unlike the formation of elemental salt crystals, the screening interactions are on the same scale as the nanoparticles, and so only short-range forces direct the assembly. The presence of smaller charged nanoparticles that act as counterions improved crystalline quality.

Navigate This Article