SERS in PAH-Os and gold nanoparticle self-assembled 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-angl...
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2005
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00219606_v123_n4_p_Tognalli https://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_00219606_v123_n4_p_Tognalli_oai |
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I28-R145-paper_00219606_v123_n4_p_Tognalli_oai2024-08-16 Tognalli, N. Fainstein, A. Calvo, E. Bonazzola, C. Pietrasanta, L. Campoy-Quiles, M. Etchegoin, P. 2005 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. application/pdf http://hdl.handle.net/20.500.12110/paper_00219606_v123_n4_p_Tognalli info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar J Chem Phys 2005;123(4) Electronic transition Gold nanoparticles Raman resonance Self-assembled multilayers Amplification Atomic force microscopy Ellipsometry Gold Nanostructured materials Polyamides Self assembly Spectroscopic analysis Multilayers SERS in PAH-Os and gold nanoparticle self-assembled multilayers info:eu-repo/semantics/article info:ar-repo/semantics/artículo info:eu-repo/semantics/publishedVersion https://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_00219606_v123_n4_p_Tognalli_oai |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-145 |
| collection |
Repositorio Digital de la Universidad de Buenos Aires (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 |
Artículo Artículo publishedVersion |
| 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 |
| publishDate |
2005 |
| url |
http://hdl.handle.net/20.500.12110/paper_00219606_v123_n4_p_Tognalli https://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_00219606_v123_n4_p_Tognalli_oai |
| work_keys_str_mv |
AT tognallin sersinpahosandgoldnanoparticleselfassembledmultilayers AT fainsteina sersinpahosandgoldnanoparticleselfassembledmultilayers AT calvoe sersinpahosandgoldnanoparticleselfassembledmultilayers AT bonazzolac sersinpahosandgoldnanoparticleselfassembledmultilayers AT pietrasantal sersinpahosandgoldnanoparticleselfassembledmultilayers AT campoyquilesm sersinpahosandgoldnanoparticleselfassembledmultilayers AT etchegoinp sersinpahosandgoldnanoparticleselfassembledmultilayers |
| _version_ |
1809356782910308352 |