Nanocompósito de óxido de grafeno e nanopartículas metálicas para espectroscopia raman amplificada por superfície (SERS)

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dc.contributor.advisorMatos, Christiano José Santiago de
dc.contributor.advisor1Latteshttp://lattes.cnpq.br/6843256597783676por
dc.contributor.authorVianna, Pilar Gregory
dc.creator.Latteshttp://lattes.cnpq.br/5168675150642820por
dc.date.accessioned2017-09-22T13:35:43Z
dc.date.accessioned2020-05-28T18:08:50Z
dc.date.available2020-05-28T18:08:50Z
dc.date.issued2017-01-24
dc.description.abstractLight interaction with the electronic cloud of metallic nanoparticles at frequencies that are resonant with the natural oscillation frequency of the cloud is known to excite localized surface plasmons. This phenomenon is widely used to enhance the Raman signal, known to have small cross sections. The technique, known as surface-enhanced Raman spectroscopy (SERS), enables the detection of chemical and biological species with high sensitivity. However, charge transfer mechanisms, adsorption/desorption and changes in the substrate morphology induce temporal instability of the SERS signal, known as blinking, which is an obstacle to the precise detection of the molecules under analysis. In this work, we, therefore, propose a SERS substrate composed of graphene oxide and gold nanorods, capable of suppressing the temporal fluctuations in the intensity of the spectrum. Temporal stability is statistically determined by the coefficient of variation of the integrated spectra, from which it is verified that, with the addition of graphene oxide, the nanocomposite is five times more stable than with gold nanorods only. The stability improvement is attributed to the removal of the nanorods’ surfactant from plasmonic hot spots due to graphene oxide-surfactant interaction. Thus, the nanocomposite is used as a reliable SERS substrate in the detection of Rhodamine 640. The analysis indicates a Rodamine detection that is four times more stable with the nanocomposite, than without graphene oxide. The nanocomposite is then used for the coating of the inner surface of microcapillaries. Graphene oxide and gold nanorod suspensions are subsequently used to fill the capillaries, with a drying step for the evaporation of solvents in between each filling stage. The continuous coating of the capillary fibers with the nanocomposite is verified by Raman spectroscopy, and Rhodamine 640 is used as a probe molecule, this time inside the capillaries, for SERS analysis. The microcapillaries allow for the use of small amounts of sample, and smaller concentrations than those detected with other reported optofluidic substrates are measured.eng
dc.description.sponsorshipConselho Nacional de Desenvolvimento Científico e Tecnológicopor
dc.description.sponsorshipFundação de Amparo a Ciência e Tecnologiapor
dc.description.sponsorshipFundo Mackenzie de Pesquisapor
dc.formatapplication/pdf*
dc.identifier.citationVIANNA, Pilar Gregory. Nanocompósito de óxido de grafeno e nanopartículas metálicas para espectroscopia raman amplificada por superfície (SERS). 2017. 90 f. Dissertação ( Engenharia Elétrica) - Universidade Presbiteriana Mackenzie, São Paulo .por
dc.identifier.urihttp://dspace.mackenzie.br/handle/10899/24451
dc.keywordsmetalliceng
dc.keywordsnanoparticleseng
dc.keywordsgraphene oxideeng
dc.keywordssurface plasmonseng
dc.keywordsSERSeng
dc.keywordsblinkingeng
dc.keywordsnanocompositeeng
dc.languageporpor
dc.publisherUniversidade Presbiteriana Mackenziepor
dc.rightsAcesso Abertopor
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/
dc.subjectnanopartículas metálicaspor
dc.subjectóxido de grafenopor
dc.subjectplásmons de superfíciepor
dc.subjectSERSpor
dc.subjectblinkingpor
dc.subjectnanocompósitopor
dc.subjectfibras capilarespor
dc.subjectoptofluídicapor
dc.subject.cnpqCNPQ::ENGENHARIAS::ENGENHARIA ELETRICApor
dc.thumbnail.urlhttp://tede.mackenzie.br/jspui/retrieve/14916/PILAR%20GREGORY%20VIANNA.pdf.jpg*
dc.titleNanocompósito de óxido de grafeno e nanopartículas metálicas para espectroscopia raman amplificada por superfície (SERS)por
dc.typeDissertaçãopor
local.contributor.board1Camargo, Pedro Henrique Cury
local.contributor.board1Latteshttp://lattes.cnpq.br/5388972564927232por
local.contributor.board2Oliveira, Rafael Euzébio Pereira de
local.contributor.board2Latteshttp://lattes.cnpq.br/4273347313516555por
local.publisher.countryBrasilpor
local.publisher.departmentEscola de Engenharia Mackenzie (EE)por
local.publisher.initialsUPMpor
local.publisher.programEngenharia Elétricapor
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