Programming “Atomic Substitution” in Alloy Colloidal Crystals Using DNA

Kaitlin M. Landy, Kyle J. Gibson, Zachary J. Urbach, Sarah S. Park, Eric W. Roth, Steven Weigand, Chad A. Mirkin*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Although examples of colloidal crystal analogues to metal alloys have been reported, general routes for preparing 3D analogues to random substitutional alloys do not exist. Here, we use the programmability of DNA (length and sequence) to match nanoparticle component sizes, define parent lattice symmetry and substitutional order, and achieve faceted crystal habits. We synthesized substitutional alloy colloidal crystals with either ordered or random arrangements of two components (Au and Fe3O4 nanoparticles) within an otherwise identical parent lattice and crystal habit, confirmed via scanning electron microscopy and small-angle X-ray scattering. Energy dispersive X-ray spectroscopy reveals information regarding composition and local order, while the magnetic properties of Fe3O4 nanoparticles can direct different structural outcomes for different alloys in an applied magnetic field. This work constitutes a platform for independently defining substitution within multicomponent colloidal crystals, a capability that will expand the scope of functional materials that can be realized through programmable assembly.

Original languageEnglish (US)
Pages (from-to)280-285
Number of pages6
JournalNano letters
Issue number1
StatePublished - Jan 12 2022


  • Crystallization
  • Genetics
  • Lattices
  • Magnetic properties
  • Nanoparticles

ASJC Scopus subject areas

  • Bioengineering
  • General Chemistry
  • General Materials Science
  • Condensed Matter Physics
  • Mechanical Engineering


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