Effect of peptide ligand dipole moments on the redox potentials of Au 38 and Au140 nanoparticles

Allan H. Holm, Marcel Ceccato, Robert L. Donkers, Laura Fabris, Giuseppe Pace, Flavio Maran

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56 Citations (Scopus)

Abstract

Phenylethanethiolate monolayer-protected Au38 and Au 140 nanoclusters were modified by ligand place exchange with a series of thiolated peptides. The peptides were homooligomers based on the α-aminoisobutyiric acid unit. The effects of changing the peptide concentration and the peptide length in the capping monolayer were studied by differential pulse voltammetry. The results showed that the redox behavior of the nanoparticles can be affected very significantly by such modifications. For example, the first oxidation peak of Au38, a cluster displaying molecule-like behavior, could be shifted positively by as much as 0.7-0.8 V. Detectable redox shifts were noted even when one single oriented peptide was in the Au140 monolayer. These effects were attributed to the molecular dipole moments of the peptide ligands.

Original languageEnglish
Pages (from-to)10584-10589
Number of pages6
JournalLangmuir
Volume22
Issue number25
DOIs
Publication statusPublished - Dec 5 2006

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ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Spectroscopy
  • Electrochemistry

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