Idriss Blakey - Interactions of Phenyldithioesters with Gold Nanoparticles (AuNPs): Implications for AuNP Functionalization and Molecular Barcoding of AuNP Assemblies.

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      Publication Details (including relevant citation   information):

      Blakey, I.; Schiller, T. L.; Merican, Z.; Fredericks, P.   M.,  Langmuir 2010, 26 (2), 692-701.

      DOI: 10.1021/la9023162

      Abstract:

      The interactions of phenyldithioesters with gold nanoparticles   (AuNPs)  have been studied by monitoring changes in the   surface plasmon resonance  (SPR), depolarised light   scattering, and surface enhanced Raman  spectroscopy (SERS).   Changes in the SPR indicated that an  AuNP-phenyldithioester   charge transfer complex forms in equilibrium with  free   AuNPs and phenyldithioester. Analysis of the Langmuir   binding  isotherms indicated that the equilibrium adsorption   constant, Kads, was 2.3 ± 0.1 ×   106 M−1, which corresponded to a free   energy of adsorption of 36 ± 1 kJ mol−1.  These   values are comparable to those reported for interactions of   aryl  thiols with gold and are of a similar order of   magnitude to moderate  hydrogen bonding interactions. This   has significant implications in the  application of   phenyldithioesters for the functionalization of AuNPs.  The   SERS results indicated that the phenyldithioesters interact   with  AuNPs through the C═S bond, and the molecules do not   disassociate upon  adsorption to the AuNPs. The SERS spectra   are dominated by the portions  of the molecule that dominate   the charge transfer complex with the  AuNPs. The   significance of this in relation to the use of    phenyldithioesters for molecular barcoding of nanoparticle   assemblies is  discussed.

      Address (URL): http://pubs.acs.org/doi/abs/10.1021/la9023162