Development and characterization of electrochemical sensors based on PAMAM dendrimers and citrate-stabilized gold nanoparticles
Autor(a) principal: | |
---|---|
Data de Publicação: | 2019 |
Tipo de documento: | Dissertação |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10400.13/2368 |
Resumo: | Electrochemical sensors are devices that allow the detection and quantification of a certain compound in a determined sample. Nanomaterials are extremely appealing for sensing purposes due their properties. Poly(amidoamine) dendrimers and gold nanoparticles are largely explored because of their small dimensions; the latter is used for its electrocatalytic properties, whilst the former is used in biosensors for its potential as an immobilization platform for biological recognition elements. This project focused on the use of PAMAM dendrimers and gold nanoparticles in electrode modification and the assessment of these modifications. Firstly, gold and glassy carbon electrodes were sequentially modified with thiols, gold layer, G5 PAMAM-NH2 dendrimers and citrate-stabilized gold nanoparticles. The modifications were monitored by cyclic voltammetry and impedance spectroscopy in a hexacyanoferrate (II)/(III) redox couple system. All modifications were successful, with the exception of citrate-stabilized gold nanoparticle, PAMAM dendrimer and mercaptopropionic sulfonic acid modified glassy carbon electrode. In a second part, the electrocatalytic activity of the modified electrodes towards 4-nitrophenol reduction in 0.05 M phosphate buffer solution was assessed by cyclic voltammetry. G5 PAMAM NH2 dendrimer assembly over vitreous carbon-based surfaces translated to electrodes with higher sensitivity, for lower limits of detection are obtained. The lowest limit of detection was calculated for PAMAM dendrimer and 3mercaptopropionic acid-modified glassy carbon electrode, 17 M, with 4-nitrophenol in linear range of 690 – 37 M. Gold substrates proved to have poor electrocatalytic activity towards 4-nitrophenol reduction owing to the simultaneous reduction of 4-nitrophenol and solution on gold surface. As for vitreous carbon substrates, the use of gold, either as a layer or as citrate-stabilized nanoparticles, resulted in less sensitive electrodes, as suggested by higher detection limits. |
id |
RCAP_46e675415b2e426787f1ebae6a4e7f8d |
---|---|
oai_identifier_str |
oai:digituma.uma.pt:10400.13/2368 |
network_acronym_str |
RCAP |
network_name_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository_id_str |
7160 |
spelling |
Development and characterization of electrochemical sensors based on PAMAM dendrimers and citrate-stabilized gold nanoparticlesSensorDendrímero PAMAMNanopartículas de ouroVoltametria cíclicaPAMAM dendrimerGold nanoparticlesCyclic voltammetryNanochemistry and Nanomaterials.Faculdade de Ciências Exatas e da EngenhariaDomínio/Área Científica::Engenharia e Tecnologia::Engenharia QuímicaDomínio/Área Científica::Engenharia e Tecnologia::Engenharia dos MateriaisElectrochemical sensors are devices that allow the detection and quantification of a certain compound in a determined sample. Nanomaterials are extremely appealing for sensing purposes due their properties. Poly(amidoamine) dendrimers and gold nanoparticles are largely explored because of their small dimensions; the latter is used for its electrocatalytic properties, whilst the former is used in biosensors for its potential as an immobilization platform for biological recognition elements. This project focused on the use of PAMAM dendrimers and gold nanoparticles in electrode modification and the assessment of these modifications. Firstly, gold and glassy carbon electrodes were sequentially modified with thiols, gold layer, G5 PAMAM-NH2 dendrimers and citrate-stabilized gold nanoparticles. The modifications were monitored by cyclic voltammetry and impedance spectroscopy in a hexacyanoferrate (II)/(III) redox couple system. All modifications were successful, with the exception of citrate-stabilized gold nanoparticle, PAMAM dendrimer and mercaptopropionic sulfonic acid modified glassy carbon electrode. In a second part, the electrocatalytic activity of the modified electrodes towards 4-nitrophenol reduction in 0.05 M phosphate buffer solution was assessed by cyclic voltammetry. G5 PAMAM NH2 dendrimer assembly over vitreous carbon-based surfaces translated to electrodes with higher sensitivity, for lower limits of detection are obtained. The lowest limit of detection was calculated for PAMAM dendrimer and 3mercaptopropionic acid-modified glassy carbon electrode, 17 M, with 4-nitrophenol in linear range of 690 – 37 M. Gold substrates proved to have poor electrocatalytic activity towards 4-nitrophenol reduction owing to the simultaneous reduction of 4-nitrophenol and solution on gold surface. As for vitreous carbon substrates, the use of gold, either as a layer or as citrate-stabilized nanoparticles, resulted in less sensitive electrodes, as suggested by higher detection limits.Sensores eletroquímicos são dispositivos que permitem a deteção e quantificação de um determinado composto numa dada amostra. Os nanomateriais são extremamente apelativos para fins sensitivos devido às suas propriedades. Os dendrímeros poli(amidoamina) (PAMAM) e as nanopartículas de ouro são muito explorados graças às suas pequenas dimensões. As nanopartículas de ouro são usadas pelas suas propriedades eletrocatalíticas, enquanto que o dendrímero é usado em biosensores pelo seu potencial como plataforma de imobilização de elementos de reconhecimento biológico. Este projeto é focado no uso de dendrímeros PAMAM e nanopartículas de ouro na modificação de elétrodos e na avaliação destas modificações. Numa primeira etapa, elétrodos de ouro e carbono foram sequencialmente modificados com tióis, camada de ouro, dendrímeros G5 PAMAM-NH2 e nanopartículas de ouro estabilizadas por citrato. As modificações foram monitorizadas por voltametria cíclica e espectroscopia de impedância num sistema com o par redox hexacianoferrato (II)/(III). Todas as modificações foram bem-sucedidas, com a exceção do elétrodo de carbono vítreo modificado com ácido 3 mercapto-1-propanosulfónico, dendrímeros PAMAM e nanopartículas de ouro estabilizadas por citrato. Numa segunda etapa, a atividade eletrocatalítica dos elétrodos modificados em relação à redução de 4-nitrofenol em solução de tampão fosfato (0.05 M) foi avaliada por voltametria cíclica. A montagem de dendrímeros PAMAM sobre elétrodos baseados em carbono vítreo traduz-se em elétrodos com maior sensibilidade, já que foram obtidos limites de deteção mais baixos. O limite de deteção mais baixo foi calculado para o elétrodo de carbono vítreo modificado com ácido 3-mercaptopropiónico e dendrímero PAMAM, 17 M, com 4-nitrofenol entre 690 – 37 M. Os substratos de ouro provaram ter uma reduzida atividade eletrocatalítica em relação à redução de 4 nitrofenol devido à redução da solução na superfície do elétrodo de ouro que ocorria em simultâneo. Quanto aos substratos de carbono vítreo, a utilização de ouro, seja sob a forma de camada ou nanopartículas estabilizadas por citrato, resultou em elétrodos menos sensíveis, como os altos limites de deteção sugerem.Mesquita, José Carlos AlmeidaRodrigues, João Manuel CunhaDigitUMaTavares, Gina Marta Ferraz2020-09-12T00:30:10Z2019-03-12T00:00:00Z2019-03-12T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10400.13/2368202247376enginfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2022-09-05T12:55:08Zoai:digituma.uma.pt:10400.13/2368Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T15:05:08.704274Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Development and characterization of electrochemical sensors based on PAMAM dendrimers and citrate-stabilized gold nanoparticles |
title |
Development and characterization of electrochemical sensors based on PAMAM dendrimers and citrate-stabilized gold nanoparticles |
spellingShingle |
Development and characterization of electrochemical sensors based on PAMAM dendrimers and citrate-stabilized gold nanoparticles Tavares, Gina Marta Ferraz Sensor Dendrímero PAMAM Nanopartículas de ouro Voltametria cíclica PAMAM dendrimer Gold nanoparticles Cyclic voltammetry Nanochemistry and Nanomaterials . Faculdade de Ciências Exatas e da Engenharia Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Química Domínio/Área Científica::Engenharia e Tecnologia::Engenharia dos Materiais |
title_short |
Development and characterization of electrochemical sensors based on PAMAM dendrimers and citrate-stabilized gold nanoparticles |
title_full |
Development and characterization of electrochemical sensors based on PAMAM dendrimers and citrate-stabilized gold nanoparticles |
title_fullStr |
Development and characterization of electrochemical sensors based on PAMAM dendrimers and citrate-stabilized gold nanoparticles |
title_full_unstemmed |
Development and characterization of electrochemical sensors based on PAMAM dendrimers and citrate-stabilized gold nanoparticles |
title_sort |
Development and characterization of electrochemical sensors based on PAMAM dendrimers and citrate-stabilized gold nanoparticles |
author |
Tavares, Gina Marta Ferraz |
author_facet |
Tavares, Gina Marta Ferraz |
author_role |
author |
dc.contributor.none.fl_str_mv |
Mesquita, José Carlos Almeida Rodrigues, João Manuel Cunha DigitUMa |
dc.contributor.author.fl_str_mv |
Tavares, Gina Marta Ferraz |
dc.subject.por.fl_str_mv |
Sensor Dendrímero PAMAM Nanopartículas de ouro Voltametria cíclica PAMAM dendrimer Gold nanoparticles Cyclic voltammetry Nanochemistry and Nanomaterials . Faculdade de Ciências Exatas e da Engenharia Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Química Domínio/Área Científica::Engenharia e Tecnologia::Engenharia dos Materiais |
topic |
Sensor Dendrímero PAMAM Nanopartículas de ouro Voltametria cíclica PAMAM dendrimer Gold nanoparticles Cyclic voltammetry Nanochemistry and Nanomaterials . Faculdade de Ciências Exatas e da Engenharia Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Química Domínio/Área Científica::Engenharia e Tecnologia::Engenharia dos Materiais |
description |
Electrochemical sensors are devices that allow the detection and quantification of a certain compound in a determined sample. Nanomaterials are extremely appealing for sensing purposes due their properties. Poly(amidoamine) dendrimers and gold nanoparticles are largely explored because of their small dimensions; the latter is used for its electrocatalytic properties, whilst the former is used in biosensors for its potential as an immobilization platform for biological recognition elements. This project focused on the use of PAMAM dendrimers and gold nanoparticles in electrode modification and the assessment of these modifications. Firstly, gold and glassy carbon electrodes were sequentially modified with thiols, gold layer, G5 PAMAM-NH2 dendrimers and citrate-stabilized gold nanoparticles. The modifications were monitored by cyclic voltammetry and impedance spectroscopy in a hexacyanoferrate (II)/(III) redox couple system. All modifications were successful, with the exception of citrate-stabilized gold nanoparticle, PAMAM dendrimer and mercaptopropionic sulfonic acid modified glassy carbon electrode. In a second part, the electrocatalytic activity of the modified electrodes towards 4-nitrophenol reduction in 0.05 M phosphate buffer solution was assessed by cyclic voltammetry. G5 PAMAM NH2 dendrimer assembly over vitreous carbon-based surfaces translated to electrodes with higher sensitivity, for lower limits of detection are obtained. The lowest limit of detection was calculated for PAMAM dendrimer and 3mercaptopropionic acid-modified glassy carbon electrode, 17 M, with 4-nitrophenol in linear range of 690 – 37 M. Gold substrates proved to have poor electrocatalytic activity towards 4-nitrophenol reduction owing to the simultaneous reduction of 4-nitrophenol and solution on gold surface. As for vitreous carbon substrates, the use of gold, either as a layer or as citrate-stabilized nanoparticles, resulted in less sensitive electrodes, as suggested by higher detection limits. |
publishDate |
2019 |
dc.date.none.fl_str_mv |
2019-03-12T00:00:00Z 2019-03-12T00:00:00Z 2020-09-12T00:30:10Z |
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.uri.fl_str_mv |
http://hdl.handle.net/10400.13/2368 202247376 |
url |
http://hdl.handle.net/10400.13/2368 |
identifier_str_mv |
202247376 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
|
_version_ |
1799129922365554688 |