Controlled colloid bonding using DNA

Materials Science Colloidal particles can act as analogs of atoms for studying crystallization and packing behavior, but they don't naturally bond together the way atoms do. Short strands of DNA are one versatile way to link together colloidal particles (see the Perspective by Tao). Kim et al. designed a series of gold colloids with DNA ligands that reversibly bound to or released neighboring particles via DNA strands that opened or closed hairpin loops. Liu et al. devised a set of DNA strands that pack into origami structures. Inside each structure were strands that cage a gold nanoparticle. These were further linked to other uncaged nanoparticles to assemble a diamond-like structure. Changing the strand design yielded a wide range of sparsely packed colloidal crystals. Science , this issue p. [561][1], p. [579][2]; see also p. [582][3] [1]: /lookup/doi/10.1126/science.aae0455 [2]: /lookup/doi/10.1126/science.aad2212 [3]: /lookup/doi/10.1126/science.aad2080