Predictions on the SERS enhancement factor of gold nanosphere aggregate samples

Colloidal gold nanostructures are nowadays widely involved in sensor applications. One of the most interesting techniques that takes advantage of them is certainly the Surface Enhanced Raman Scattering (SERS) effect, even if it is often considered a tricky technique due to structural constraints req...

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Bibliographic Details
Published inPhysical chemistry chemical physics : PCCP Vol. 21; no. 28; pp. 15515 - 15522
Main Authors Litti, Lucio, Meneghetti, Moreno
Format Journal Article
LanguageEnglish
Published England Royal Society of Chemistry 17.07.2019
Subjects
Aggregates
Boundary element method
Colloids
Extinction
Gold
Mathematical analysis
Nanoparticles
Nanospheres
Predictions
Raman spectra
Substrates
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Summary:Colloidal gold nanostructures are nowadays widely involved in sensor applications. One of the most interesting techniques that takes advantage of them is certainly the Surface Enhanced Raman Scattering (SERS) effect, even if it is often considered a tricky technique due to structural constraints required by the nanostructured substrates to obtain high enhancement factors (EFs), i.e. the presence of hot spots. Because of the easy preparation and high number of hot spots, aggregated gold nanospheres seem to be the most efficient through the SERS colloids, but their characteristic high disorder makes them unpredictable and difficult to compare between different batches. For this reason, less SERS effective, but more regular and organized substrates are usually preferred. In this study, a method based on Boundary Element Method (BEM) simulation is used to accurately predict the colloidal SERS EFs of gold nanoparticle (AuNP) aggregates, starting from their experimental extinction spectra. Surprisingly, it was found that larger aggregates do not exhibit stronger hot spots, but rather higher amounts of them, influencing the overall predicted EFs, which well reflect the results obtained experimentally. A boundary element method simulation is used to accurately predict the SERS EFs of gold nanoparticle aggregates via their experimental extinction spectra.
Bibliography:10.1039/c9cp02015b
Electronic supplementary information (ESI) available: TEM images, analysis of other different clustered nanospheres, as well as all the structures and the simulated extinction spectra used in this study. See DOI
ISSN:1463-9076
1463-9084
DOI:10.1039/c9cp02015b