SERS in PAH-Os and gold nanoparticle self-assembled multilayers

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We present a detailed structural and surface-enhanced Raman scattering (SERS) study of poly(allylamine) modified with Os (byp)2 ClPyCHO (PAH-Os) and gold nanoparticles self-assembled multilayers [PAH-Os+ (Au-nanoparticlesPAH-Os)n, n=1 and 5]. Atomic force microscopy and variable-angle spectroscopic...

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Autores principales: Tognalli, N., Fainstein, A., Calvo, E., Bonazzola, C., Pietrasanta, L., Campoy-Quiles, M., Etchegoin, P.
Formato: JOUR
Materias:
Electronic transition
Gold nanoparticles
Raman resonance
Self-assembled multilayers
Amplification
Atomic force microscopy
Ellipsometry
Gold
Nanostructured materials
Polyamides
Self assembly
Spectroscopic analysis
Multilayers
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00219606_v123_n4_p_Tognalli
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_00219606_v123_n4_p_Tognalli2023-10-03T14:24:09Z SERS in PAH-Os and gold nanoparticle self-assembled multilayers Tognalli, N. Fainstein, A. Calvo, E. Bonazzola, C. Pietrasanta, L. Campoy-Quiles, M. Etchegoin, P. Electronic transition Gold nanoparticles Raman resonance Self-assembled multilayers Amplification Atomic force microscopy Ellipsometry Gold Nanostructured materials Polyamides Self assembly Spectroscopic analysis Multilayers We present a detailed structural and surface-enhanced Raman scattering (SERS) study of poly(allylamine) modified with Os (byp)2 ClPyCHO (PAH-Os) and gold nanoparticles self-assembled multilayers [PAH-Os+ (Au-nanoparticlesPAH-Os)n, n=1 and 5]. Atomic force microscopy and variable-angle spectroscopic ellipsometry measurements indicate that the first nanoparticle layer grows homogenously by partially covering the substrate without clustering. Analyzing the sample thickness and roughness we infer that the growth process advances thereafter by filling with nanoparticles the interstitial spaces between the previously adsorbed nanoparticles. After five immersion steps the multilayers reach a more compact structure. The interaction between plasmons of near-gold nanoparticles provides a new optical absorption around 650 nm which, in addition, allows a more effective SERS process in that spectral region than at the single-plasmon resonance (∼530 nm). We compare the electronic resonance Raman and SERS amplification mechanisms in these self-assembled multilayers analyzing Raman resonance scans and Raman intensity micromaps. As a function of nanoparticle coverage we observe large changes in the Raman intensity scans, with maxima that shift from the electronic transitions, to the plasmon resonance, and finally to the coupled-plasmon absorption. The Raman micromaps, on the other hand, evidence huge intensity inhomogeneities which we relate to "hot spots." Numerical discrete dipole approximation calculations including the interaction between gold nanoparticles are presented, providing a qualitative model for the coupled-plasmon absorption and redshifted Raman hot spots in these samples. © 2005 American Institute of Physics. Fil:Calvo, E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Bonazzola, C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00219606_v123_n4_p_Tognalli
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Electronic transition
Gold nanoparticles
Raman resonance
Self-assembled multilayers
Amplification
Atomic force microscopy
Ellipsometry
Gold
Nanostructured materials
Polyamides
Self assembly
Spectroscopic analysis
Multilayers
spellingShingle Electronic transition
Gold nanoparticles
Raman resonance
Self-assembled multilayers
Amplification
Atomic force microscopy
Ellipsometry
Gold
Nanostructured materials
Polyamides
Self assembly
Spectroscopic analysis
Multilayers
Tognalli, N.
Fainstein, A.
Calvo, E.
Bonazzola, C.
Pietrasanta, L.
Campoy-Quiles, M.
Etchegoin, P.
SERS in PAH-Os and gold nanoparticle self-assembled multilayers
topic_facet Electronic transition
Gold nanoparticles
Raman resonance
Self-assembled multilayers
Amplification
Atomic force microscopy
Ellipsometry
Gold
Nanostructured materials
Polyamides
Self assembly
Spectroscopic analysis
Multilayers
description We present a detailed structural and surface-enhanced Raman scattering (SERS) study of poly(allylamine) modified with Os (byp)2 ClPyCHO (PAH-Os) and gold nanoparticles self-assembled multilayers [PAH-Os+ (Au-nanoparticlesPAH-Os)n, n=1 and 5]. Atomic force microscopy and variable-angle spectroscopic ellipsometry measurements indicate that the first nanoparticle layer grows homogenously by partially covering the substrate without clustering. Analyzing the sample thickness and roughness we infer that the growth process advances thereafter by filling with nanoparticles the interstitial spaces between the previously adsorbed nanoparticles. After five immersion steps the multilayers reach a more compact structure. The interaction between plasmons of near-gold nanoparticles provides a new optical absorption around 650 nm which, in addition, allows a more effective SERS process in that spectral region than at the single-plasmon resonance (∼530 nm). We compare the electronic resonance Raman and SERS amplification mechanisms in these self-assembled multilayers analyzing Raman resonance scans and Raman intensity micromaps. As a function of nanoparticle coverage we observe large changes in the Raman intensity scans, with maxima that shift from the electronic transitions, to the plasmon resonance, and finally to the coupled-plasmon absorption. The Raman micromaps, on the other hand, evidence huge intensity inhomogeneities which we relate to "hot spots." Numerical discrete dipole approximation calculations including the interaction between gold nanoparticles are presented, providing a qualitative model for the coupled-plasmon absorption and redshifted Raman hot spots in these samples. © 2005 American Institute of Physics.
format JOUR
author Tognalli, N.
Fainstein, A.
Calvo, E.
Bonazzola, C.
Pietrasanta, L.
Campoy-Quiles, M.
Etchegoin, P.
author_facet Tognalli, N.
Fainstein, A.
Calvo, E.
Bonazzola, C.
Pietrasanta, L.
Campoy-Quiles, M.
Etchegoin, P.
author_sort Tognalli, N.
title SERS in PAH-Os and gold nanoparticle self-assembled multilayers
title_short SERS in PAH-Os and gold nanoparticle self-assembled multilayers
title_full SERS in PAH-Os and gold nanoparticle self-assembled multilayers
title_fullStr SERS in PAH-Os and gold nanoparticle self-assembled multilayers
title_full_unstemmed SERS in PAH-Os and gold nanoparticle self-assembled multilayers
title_sort sers in pah-os and gold nanoparticle self-assembled multilayers
url http://hdl.handle.net/20.500.12110/paper_00219606_v123_n4_p_Tognalli
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