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Molecular hot spots in surface-enhanced Raman scattering

Li, Ming and Cushing, Scott K. and Zhou, Guangwen and Wu, Nianqiang (2020) Molecular hot spots in surface-enhanced Raman scattering. Nanoscale, 12 (43). pp. 22036-22041. ISSN 2040-3364. https://resolver.caltech.edu/CaltechAUTHORS:20201105-160425769

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Abstract

The chemical and electromagnetic (EM) enhancements both contribute to surface-enhanced Raman scattering (SERS). It is well-known that the EM enhancement is induced by the intense local field of surface plasmon resonance (SPR). This report shows that the polarizability of the molecules adsorbed on the metal surface can lead to another channel for the EM field enhancement. When aromatic molecules are covalently bonded to the Au surface, they strongly interact with the plasmon, leading to a modification of the absorption spectrum and a strong SERS signal. The effect is seen in both 3 nm-Au nanoparticles with a weak SPR and 15 nm-Au nanoparticles with a strong SPR, suggesting that the coupling is through both EM field and chemical means. Linear-chain molecules on the 3 nm-Au nanoparticles do not have a SERS signal. However, when the aromatic and linear molecules are co-adsorbed, the strong SPR/molecular polarizability interaction spatially extends the local EM field, leading to a strong SERS signal from the linear-chain molecules. The results show that aromatic molecules immobilized on Au can create “hot spots” just like plasmonic nanostructures.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1039/d0nr06579jDOIArticle
ORCID:
AuthorORCID
Li, Ming0000-0002-2289-0222
Cushing, Scott K.0000-0003-3538-2259
Zhou, Guangwen0000-0002-9243-293X
Wu, Nianqiang0000-0002-8888-2444
Additional Information:© The Royal Society of Chemistry 2020. Received 12th September 2020, Accepted 23rd October 2020. N. W. is partially supported by the Armstrong-Siadat Professorship Endowment. Conflicts of interest. There are no conflicts to declare.
Funders:
Funding AgencyGrant Number
Armstrong-Siadat Professorship EndowmentUNSPECIFIED
Issue or Number:43
Record Number:CaltechAUTHORS:20201105-160425769
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20201105-160425769
Official Citation:Molecular hot spots in surface-enhanced Raman scattering. Nanoscale, 2020, 12, 22036-22041; DOI: 10.1039/d0nr06579j
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:106467
Collection:CaltechAUTHORS
Deposited By: George Porter
Deposited On:06 Nov 2020 15:22
Last Modified:25 Nov 2020 17:35

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