Iodide-Induced Organothiol Desorption and Photochemical Reaction, Gold Nanoparticle (AuNP) Fusion, and SERS Signal Reduction in Organothiol-Containing AuNP Aggregates

    Authors

    G. S. Perera; A. LaCour; Y. D. Zhou; K. L. Henderson; S. L. Zou; F. Perez; J. P. Emerson;D. M. Zhang

    Comments

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    Abbreviated Journal Title

    J. Phys. Chem. C

    Keywords

    ENHANCED RAMAN-SCATTERING; SODIUM-BOROHYDRIDE; CHEMICAL ENHANCEMENT; SINGLE-MOLECULE; WATER; DESULFURIZATION; CHEMISTRY; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, ; Multidisciplinary

    Abstract

    Gold nanoparticles (AuNPs) have been used extensively as surface-enhanced Raman spectroscopic (SERS) substrates for their large SERS enhancements and widely believed chemical stability. Presented is the finding that iodide can rapidly reduce the SERS intensity of the ligands, including organothiols adsorbed on plasmonic AuNPs through both iodide-induced ligand desorption and AuNP fusion. The organothiols trapped inside the fused AuNPs have negligible SERS activities. Multiple photochemical processes were involved when organothiol-containing AuNP aggregates were treated with KI under photoillumination. The photocatalytically produced I-3(-) reacts with both organothiol and AuNPs. Chloride and bromide also induce partial organothiol displacement and the fusion of the as-synthesized AuNPs, but neither of the two halides has detectable effects on the morphology and Raman signals of the organothiol-containing AuNP aggregates. The insight provided in this work should be important for the understanding of interfacial interactions of plasmonic AuNPs and their SERS applications.

    Journal Title

    Journal of Physical Chemistry C

    Volume

    119

    Issue/Number

    8

    Publication Date

    1-1-2015

    Document Type

    Article

    Language

    English

    First Page

    4261

    Last Page

    4267

    WOS Identifier

    WOS:000350329300041

    ISSN

    1932-7447

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