Cited research Science 329, 197–200 (2010)

Making nanoparticles has become relatively straightforward, but assembling them into more complex structures in a predictable way has proved more difficult. Researchers have now modified gold nanorods so that they polymerize to form linear, branched and cyclical structures (pictured).

Eugenia Kumacheva at the University of Toronto in Canada, Michael Rubinstein at the University of North Carolina at Chapel Hill and their colleagues synthesized their nanorods with 'arrowheads' on each end that were then coated with polystyrene molecules. Another compound covered the sides of the rods to prevent side-by-side aggregation.

The rods linked up with each other end-to-end to form chains through the association of polystyrene molecules as the researchers adjusted the composition of the solvent to reduce the solubility of polystyrene. The authors were able to control the aggregation number and architecture of the structures. C.L.

Credit: SCIENCE/AAAS