Iodide-Induced Organothiol Desorption And Photochemical Reaction, Gold Nanoparticle (Aunp) Fusion, And Sers Signal Reduction In Organothiol-Containing Aunp Aggregates

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 I3- 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.

Publication Date

2-26-2015

Publication Title

Journal of Physical Chemistry C

Volume

119

Issue

8

Number of Pages

4261-4267

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1021/jp512168z

Socpus ID

84923950850 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84923950850

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