Figure 2: Colloidal crystals assembled from DNA-coated colloids.

Confocal fluorescent images and corresponding drawings showing various crystals fabricated from DNA-coated colloids of different sizes and stoichiometries. (a) 1.0-μm P particles form face-centered cubic lattice, whose 111, 100, 110 and 311 planes are displayed. (b) An AB lattice (isostructural to CsCl) assembled from 1.0-μm A and 1.0-μm B particles with complementary DNA sticky ends. Multiple lattice planes are observed including, from left to right, 110, 100, 111 and 211 planes. (c) An AB₂ crystal (isostructural to AlB₂) is obtained using 1.0-μm A and 0.54-μm B particles. 100, 001, 111 and 101 planes are shown. (d) An AB₆ crystal lattice (isostructural to Cs₆C₆₀) assembled from 1.5-μm A and 0.54-μm B particles. 110 and 100 planes are shown, accompanied by the corresponding red channel showing only the structural arrangement for the 0.54-μm particles. Interestingly, we find that the AB₆ structure can tolerate a large number of B vacancies, up to 50%, at the surface of the crystals, while in the bulk there appear to be far fewer. Scale bar, 5 μm.