The shape of nanoparticles is key to their properties and, hence, their uses. However, controlling the size and shape while growing nanoparticles represents a major challenge in nanotechnology.

Now, recognizing that nanoparticle growth is a kinetic process in which facets grow and disappear in particles as they form in a colloidal suspension, US chemists have used peptides to control this process. By tailoring the sequence to have an affinity for particular facets, the team could nudge the growth of facets down a specific kinetic path, allowing them to choose either tetrahedral or cubic platinum nanoparticles.

• Platinum nanocrystals selectively shaped using facet-specific peptide sequences
  C.-Y. Chiu, Y. Li, L. Ruan, X. Ye, C. B. Murray, Y. Huang,
  Nature Chem. 2011, 3, 393-399.
  DOI: 10.1038/nchem.1025