Formação de filme polimérico derivado de ácido 3-hidroxifenilacético para a construção de biosensores
Autor(a) principal: | |
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Data de Publicação: | 2010 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFU |
Texto Completo: | https://repositorio.ufu.br/handle/123456789/17314 |
Resumo: | A polymer derived from 3-hydroxi phenyl acetic acid, poly-(3-HFA) was produced over a graphite electrode in an aqueous acid media through cyclic voltammetry with the intention to form an interface for biomolecule detection for a biosensor development. Cyclic voltammograms show that electropolymerization process begins around +0.9V, with the appearance of an oxidation wave reaching a peak potential at +1.06V. This wave is pointed as being the monomer oxidation for its cation-radical form. With a second cycle there is a current values decrease of this wave and a redox pair waves appears between +0.3 and +0.7V. This pair refers to the redox process of the polymeric film, growing over the electrode surface. As the sweep number increases it is observed a large current values increase of these redox waves, pointing the formation of electroactive material with a low insulating behavior. The electrical properties of this polymer were determined through electrochemical impedance spectroscopy (EIS) and the electrochemical quartz crystal microbalance (EQCM). high frequency and another in low frequency ranges, suggesting the existence of two time constants, which can be confirmed through Bode diagram. This result suggest that the poly-(3- HFA) electrochemical behavior is controlled by kinetic processes in high frequency ranges and by mass transport in low frequency ranges. The obtained result were simulated by a set of physical resistances and capacitances to fit to the experimental data, seeking the better circuit to represent it, which the first time constant is referred to an electronic transference on the electrode surface between the polymer and the solution and the second refers to mass transport processes in poly-(3-HFA) inner layers. For the EQCM result, it is observed that the charge/frequency profile present a linear behavior, namely, a rigid film is being deposited over the electrode surface and the Sauerbrey equation is valid for the mass calculus. It is observed that, on the first cycle, the mass values remained constant until around +0.9V, exactly where the electropolymerization process begins. After 1.0V, the monomer, reaching its oxidation potential, begins to form the cation-radical structures which adsorbs on the electrode proved by the mass values increase. During the reverse potential sweep, there is an additional mass increase due to the part of the monomer oxidation over this range. After this point, a little mass values decrease is observed, however, remaining constant until the end of the cycle. |
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2016-06-22T18:48:24Z2010-05-052016-06-22T18:48:24Z2010-06-30OLIVEIRA, Ronalt Marcelino Lemos de. Formação de filme polimérico derivado de ácido 3-hidroxifenilacético para a construção de biosensores. 2010. 81 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de Uberlândia, Uberlândia, 2010.https://repositorio.ufu.br/handle/123456789/17314A polymer derived from 3-hydroxi phenyl acetic acid, poly-(3-HFA) was produced over a graphite electrode in an aqueous acid media through cyclic voltammetry with the intention to form an interface for biomolecule detection for a biosensor development. Cyclic voltammograms show that electropolymerization process begins around +0.9V, with the appearance of an oxidation wave reaching a peak potential at +1.06V. This wave is pointed as being the monomer oxidation for its cation-radical form. With a second cycle there is a current values decrease of this wave and a redox pair waves appears between +0.3 and +0.7V. This pair refers to the redox process of the polymeric film, growing over the electrode surface. As the sweep number increases it is observed a large current values increase of these redox waves, pointing the formation of electroactive material with a low insulating behavior. The electrical properties of this polymer were determined through electrochemical impedance spectroscopy (EIS) and the electrochemical quartz crystal microbalance (EQCM). high frequency and another in low frequency ranges, suggesting the existence of two time constants, which can be confirmed through Bode diagram. This result suggest that the poly-(3- HFA) electrochemical behavior is controlled by kinetic processes in high frequency ranges and by mass transport in low frequency ranges. The obtained result were simulated by a set of physical resistances and capacitances to fit to the experimental data, seeking the better circuit to represent it, which the first time constant is referred to an electronic transference on the electrode surface between the polymer and the solution and the second refers to mass transport processes in poly-(3-HFA) inner layers. For the EQCM result, it is observed that the charge/frequency profile present a linear behavior, namely, a rigid film is being deposited over the electrode surface and the Sauerbrey equation is valid for the mass calculus. It is observed that, on the first cycle, the mass values remained constant until around +0.9V, exactly where the electropolymerization process begins. After 1.0V, the monomer, reaching its oxidation potential, begins to form the cation-radical structures which adsorbs on the electrode proved by the mass values increase. During the reverse potential sweep, there is an additional mass increase due to the part of the monomer oxidation over this range. After this point, a little mass values decrease is observed, however, remaining constant until the end of the cycle.Um filme polimérico derivado de ácido 3-hidroxifenilacético poli-3-HFA foi produzido sobre eletrodo de grafite em meio aquoso ácido utilizando voltametria cíclica com a finalidade de formar uma interface para a detecção de biomoléculas para o desenvolvimento de biossensores. Voltamogramas cíclicos mostram que o processo de eletropolimerização se inicia por volta de +0,9V, com o surgimento de uma onda de oxidação, atingindo um potencial de pico a +1,06V. Essa onda é apontada como sendo a oxidação do monômero estudado em questão para sua forma cátion-radical. Com um segundo ciclo, há uma queda nos valores de corrente dessa onda e um par de ondas redox surge entre os potenciais +0,3 e +0,7V. Esse par se refere ao processo redox do filme polimérico em crescimento na superfície do eletrodo. Com o aumento do número de varreduras é observado um grande aumento nos valores de corrente destas ondas redox, indicando a formação de materiais na superfície do eletrodo. Um estudo de estabilidade do material produzido foi feito com a técnica da voltamentria cíclica e o material polimérico foi caracterizado utilizando-se algumas técnicas como: microscopia de força atômica (AFM), espectroscopia de impedância eletroquímica (EIE) e microbalança eletroquímica de cristal de quartzo (MECQ). O eletrodo modificado com uma película delgada de Poli-3-HFA foi utilizado para a incorporação de biomoléculas. Na imobilização direta um fragmento de Poli-adenosina -poli(A) foi incorporado a superfície do eletrodo e uma modificação do sinal eletroquímico do sistema foi observado. Após a hibridização do poli(A) contido na superfície modificada do filme polimérico com uma fita de poli-timidina Poli(T) observou-se outra alteração no sinal eletroquímico produzido pelo eletrodo indicando materiais diferentes em sua superfície. Já na imobilização indireta, utilizou-se o azul de metileno como intermediador e assim obteve-se também, diferentes respostas eletroquímicas com o eletrodo modificado com Poli-3- HFA, como com Poli-3-HFA/Poli(A) e Poli-3-HFA/poli(A)/poli(T). Portanto a superfície de um eletrodo de grafite pode ser modificada com um polímero derivado de ácido 3-HFA e esse filme pode ser utilizado para a incorporação de biomoléculas btendo-se diferentes respostas eletroquímicas.Mestre em Químicaapplication/pdfporUniversidade Federal de UberlândiaPrograma de Pós-graduação em QuímicaUFUBRCiências Exatas e da TerraPolímerosBiosensoresNanotecnologiaCNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICAFormação de filme polimérico derivado de ácido 3-hidroxifenilacético para a construção de biosensoresinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisMadurro, João Marcoshttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4782738T7Abrahão Júnior, Odoníriohttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4799976D8Guilardi, Silvanahttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4780176Y7http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4282501T0Oliveira, Ronalt Marcelino Lemos deinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFUinstname:Universidade Federal de Uberlândia (UFU)instacron:UFUTHUMBNAIL1p.pdf.jpg1p.pdf.jpgGenerated Thumbnailimage/jpeg1488https://repositorio.ufu.br/bitstream/123456789/17314/5/1p.pdf.jpg9f5c46a8f4f4296aef8dd871b3c6e127MD552p.pdf.jpg2p.pdf.jpgGenerated Thumbnailimage/jpeg1508https://repositorio.ufu.br/bitstream/123456789/17314/6/2p.pdf.jpge0310f36d783ca6e32e3aef40f296026MD56ORIGINAL1p.pdfapplication/pdf3423334https://repositorio.ufu.br/bitstream/123456789/17314/1/1p.pdf05102c07b5d6096cc8da19dfbf37d0e7MD512p.pdfapplication/pdf7636054https://repositorio.ufu.br/bitstream/123456789/17314/2/2p.pdfdc83e655649fbdc5c0082906ba420705MD52TEXT1p.pdf.txt1p.pdf.txtExtracted texttext/plain71442https://repositorio.ufu.br/bitstream/123456789/17314/3/1p.pdf.txt28a8496de42bc7f7a4fc35645eceb8a1MD532p.pdf.txt2p.pdf.txtExtracted texttext/plain66434https://repositorio.ufu.br/bitstream/123456789/17314/4/2p.pdf.txt0d2fe14d87026162693065a3e1040510MD54123456789/173142016-06-23 04:47:14.133oai:repositorio.ufu.br:123456789/17314Repositório InstitucionalONGhttp://repositorio.ufu.br/oai/requestdiinf@dirbi.ufu.bropendoar:2016-06-23T07:47:14Repositório Institucional da UFU - Universidade Federal de Uberlândia (UFU)false |
dc.title.por.fl_str_mv |
Formação de filme polimérico derivado de ácido 3-hidroxifenilacético para a construção de biosensores |
title |
Formação de filme polimérico derivado de ácido 3-hidroxifenilacético para a construção de biosensores |
spellingShingle |
Formação de filme polimérico derivado de ácido 3-hidroxifenilacético para a construção de biosensores Oliveira, Ronalt Marcelino Lemos de Polímeros Biosensores Nanotecnologia CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
title_short |
Formação de filme polimérico derivado de ácido 3-hidroxifenilacético para a construção de biosensores |
title_full |
Formação de filme polimérico derivado de ácido 3-hidroxifenilacético para a construção de biosensores |
title_fullStr |
Formação de filme polimérico derivado de ácido 3-hidroxifenilacético para a construção de biosensores |
title_full_unstemmed |
Formação de filme polimérico derivado de ácido 3-hidroxifenilacético para a construção de biosensores |
title_sort |
Formação de filme polimérico derivado de ácido 3-hidroxifenilacético para a construção de biosensores |
author |
Oliveira, Ronalt Marcelino Lemos de |
author_facet |
Oliveira, Ronalt Marcelino Lemos de |
author_role |
author |
dc.contributor.advisor1.fl_str_mv |
Madurro, João Marcos |
dc.contributor.advisor1Lattes.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4782738T7 |
dc.contributor.referee1.fl_str_mv |
Abrahão Júnior, Odonírio |
dc.contributor.referee1Lattes.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4799976D8 |
dc.contributor.referee2.fl_str_mv |
Guilardi, Silvana |
dc.contributor.referee2Lattes.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4780176Y7 |
dc.contributor.authorLattes.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4282501T0 |
dc.contributor.author.fl_str_mv |
Oliveira, Ronalt Marcelino Lemos de |
contributor_str_mv |
Madurro, João Marcos Abrahão Júnior, Odonírio Guilardi, Silvana |
dc.subject.por.fl_str_mv |
Polímeros Biosensores Nanotecnologia |
topic |
Polímeros Biosensores Nanotecnologia CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
dc.subject.cnpq.fl_str_mv |
CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
description |
A polymer derived from 3-hydroxi phenyl acetic acid, poly-(3-HFA) was produced over a graphite electrode in an aqueous acid media through cyclic voltammetry with the intention to form an interface for biomolecule detection for a biosensor development. Cyclic voltammograms show that electropolymerization process begins around +0.9V, with the appearance of an oxidation wave reaching a peak potential at +1.06V. This wave is pointed as being the monomer oxidation for its cation-radical form. With a second cycle there is a current values decrease of this wave and a redox pair waves appears between +0.3 and +0.7V. This pair refers to the redox process of the polymeric film, growing over the electrode surface. As the sweep number increases it is observed a large current values increase of these redox waves, pointing the formation of electroactive material with a low insulating behavior. The electrical properties of this polymer were determined through electrochemical impedance spectroscopy (EIS) and the electrochemical quartz crystal microbalance (EQCM). high frequency and another in low frequency ranges, suggesting the existence of two time constants, which can be confirmed through Bode diagram. This result suggest that the poly-(3- HFA) electrochemical behavior is controlled by kinetic processes in high frequency ranges and by mass transport in low frequency ranges. The obtained result were simulated by a set of physical resistances and capacitances to fit to the experimental data, seeking the better circuit to represent it, which the first time constant is referred to an electronic transference on the electrode surface between the polymer and the solution and the second refers to mass transport processes in poly-(3-HFA) inner layers. For the EQCM result, it is observed that the charge/frequency profile present a linear behavior, namely, a rigid film is being deposited over the electrode surface and the Sauerbrey equation is valid for the mass calculus. It is observed that, on the first cycle, the mass values remained constant until around +0.9V, exactly where the electropolymerization process begins. After 1.0V, the monomer, reaching its oxidation potential, begins to form the cation-radical structures which adsorbs on the electrode proved by the mass values increase. During the reverse potential sweep, there is an additional mass increase due to the part of the monomer oxidation over this range. After this point, a little mass values decrease is observed, however, remaining constant until the end of the cycle. |
publishDate |
2010 |
dc.date.available.fl_str_mv |
2010-05-05 2016-06-22T18:48:24Z |
dc.date.issued.fl_str_mv |
2010-06-30 |
dc.date.accessioned.fl_str_mv |
2016-06-22T18:48:24Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
OLIVEIRA, Ronalt Marcelino Lemos de. Formação de filme polimérico derivado de ácido 3-hidroxifenilacético para a construção de biosensores. 2010. 81 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de Uberlândia, Uberlândia, 2010. |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufu.br/handle/123456789/17314 |
identifier_str_mv |
OLIVEIRA, Ronalt Marcelino Lemos de. Formação de filme polimérico derivado de ácido 3-hidroxifenilacético para a construção de biosensores. 2010. 81 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de Uberlândia, Uberlândia, 2010. |
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https://repositorio.ufu.br/handle/123456789/17314 |
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Universidade Federal de Uberlândia |
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Programa de Pós-graduação em Química |
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UFU |
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BR |
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Ciências Exatas e da Terra |
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Universidade Federal de Uberlândia |
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UFU |
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Repositório Institucional da UFU |
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Repositório Institucional da UFU |
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