Assembly of colloidal semiconductor nanorods in solution by depletion attraction

Dmitry Baranov, Angela Fiore, Marijn Van Huis, Cinzia Giannini, Andrea Falqui, Ugo Lafont, Henny Zandbergen, Marco Zanella, Roberto Cingolani, Liberato Manna*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

250 Scopus citations


Arranging anisotropic nanoparticles into ordered assemblies remains a challenging quest requiring innovative and Ingenuous approaches. The variety of interactions present in colloidal solutions of nonspherical inorganic nanocrystals can be exploited for this purpose. By tuning depletion attraction forces between hydrophobic colloidal nanorods of semiconductors, dispersed in an organic solvent, these could be assembled into 2D monolayers of close-packed hexagonally ordered arrays directly in solution. Once formed, these layers could be fished onto a substrate, and sheets of vertically standing rods were fabricated, with no additional external bias applied. Alternatively, the assemblies could be isolated and redispersed in polar solvents, yielding suspensions of micrometer-sized sheets which could be chemically treated directly in solution. Depletion attraction forces were also effective in the shape-selective separation of nanorods from binary mixtures of rods and spheres. The reported procedures have the potential to enable powerful and cost-effective fabrication approaches to materials and devices based on self-organized anisotropic nanoparticles.

Original languageEnglish (US)
Pages (from-to)743-749
Number of pages7
JournalNano Letters
Issue number2
StatePublished - Feb 10 2010
Externally publishedYes


  • Depletion forces
  • Nanocrystals
  • Nanorods
  • Self-assembly

ASJC Scopus subject areas

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


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