Estudos de aplicações eletroquímicas de nanocristais semicondutores de CdTe crescidos em matrizes inorgânicas
Autor(a) principal: | |
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Data de Publicação: | 2019 |
Tipo de documento: | Tese |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFS |
Texto Completo: | http://ri.ufs.br/jspui/handle/riufs/11004 |
Resumo: | In the present work, CdTe nanocrystals were synthesized on inorganic matrices of mesoporous silicas (MS) and lamellar hydroxides (HDL) with the objective of developing efficient and selective methods for the electrochemical detection of copper and ciprofloxacin (CPX). For the mesoporous samples, made through different synthesis methodologies, were evaluated the influence of the surface area, volumes and pore diameters of the silica matrices on the confinement process of the semiconductor particles and it was observed that the emission properties of CdTe (quantum dots, QD) depends on the texture properties of the silicas. For both inorganic matrices, results of absorption and emission spectroscopy, as well as high-resolution transmission electron microscopy images (HRTEM), evidenced a formation of hybrid materials containing CdTe nanocrystals. The electrochemical characterization of the chemically modified carbon electrodes (EQM) containing the compounds (EQM-MS4/QD and EQM-HDL/QD) show that the presence of CdTe nanocrystals, leads to an increase in the detection sensibility toward the studied analytes. After the optimization step, the working electrode made up using the modifier MS4/QD responded to a linear Cu2+ detection of 5.0 x 10-8 to 2.3 x 10-6 mol L-1 (R2 = 0,9974) and the calculated limit of detection (LOD) was 6.4 x 10-8 mol L-1. The method developed was efficient for the monitoring of Cu2+ in the sugarcane liquor, being compared with the outcomes from Flame atomic absorbtion spectroscopy (FAAS). The detection of CPX was made EQM-HDL/QD, with 20% of modifier, pH 6.0, BR buffer (Britton-Robinson), accumulation time of 300 s and scan rate of 20 mV s-1, in the range 2.5 x 10-8 to 1.2 x 10-5 mol L-1 (R2 = 0.9970), a sensitivity of LOD = 4.2 x 10-8 mol L-1 and limit of quantification (LOQ) of 1.3 x 10-7 mol L-1, accuracy of 3.0%, recovery of 94.0% and satisfactory selectivity in the presence of some interferents. Tests of CPX determination in commercial capsules of 500 mg of ciprofloxacin showed the applicability of the method. |
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Carvalho, Sanny Wedja Melo Machado deGimenez, Iara de FátimaSussuchi, Eliana Midori2019-04-23T19:35:11Z2019-04-23T19:35:11Z2019-02-20CARVALHO, Sanny Wedja Melo Machado de. Estudos de aplicações eletroquímicas de nanocristais semicondutores de CdTe crescidos em matrizes inorgânicas. 2019. 147 f. Tese (Doutorado em Química) - Universidade Federal de Sergipe, São Cristóvão, SE, 2019.http://ri.ufs.br/jspui/handle/riufs/11004In the present work, CdTe nanocrystals were synthesized on inorganic matrices of mesoporous silicas (MS) and lamellar hydroxides (HDL) with the objective of developing efficient and selective methods for the electrochemical detection of copper and ciprofloxacin (CPX). For the mesoporous samples, made through different synthesis methodologies, were evaluated the influence of the surface area, volumes and pore diameters of the silica matrices on the confinement process of the semiconductor particles and it was observed that the emission properties of CdTe (quantum dots, QD) depends on the texture properties of the silicas. For both inorganic matrices, results of absorption and emission spectroscopy, as well as high-resolution transmission electron microscopy images (HRTEM), evidenced a formation of hybrid materials containing CdTe nanocrystals. The electrochemical characterization of the chemically modified carbon electrodes (EQM) containing the compounds (EQM-MS4/QD and EQM-HDL/QD) show that the presence of CdTe nanocrystals, leads to an increase in the detection sensibility toward the studied analytes. After the optimization step, the working electrode made up using the modifier MS4/QD responded to a linear Cu2+ detection of 5.0 x 10-8 to 2.3 x 10-6 mol L-1 (R2 = 0,9974) and the calculated limit of detection (LOD) was 6.4 x 10-8 mol L-1. The method developed was efficient for the monitoring of Cu2+ in the sugarcane liquor, being compared with the outcomes from Flame atomic absorbtion spectroscopy (FAAS). The detection of CPX was made EQM-HDL/QD, with 20% of modifier, pH 6.0, BR buffer (Britton-Robinson), accumulation time of 300 s and scan rate of 20 mV s-1, in the range 2.5 x 10-8 to 1.2 x 10-5 mol L-1 (R2 = 0.9970), a sensitivity of LOD = 4.2 x 10-8 mol L-1 and limit of quantification (LOQ) of 1.3 x 10-7 mol L-1, accuracy of 3.0%, recovery of 94.0% and satisfactory selectivity in the presence of some interferents. Tests of CPX determination in commercial capsules of 500 mg of ciprofloxacin showed the applicability of the method.No presente trabalho, nanocristais de CdTe foram sintetizados em matrizes inorgânicas do tipo sílicas mesoporosas (MS) e hidróxidos duplos lamelares (HDL) com o objetivo de desenvolver métodos sensíveis e seletivos para a detecção eletroquímica de cobre e ciprofloxacina (CPX). Para as sílicas mesoporosas, através de diferentes metodologias de síntese, foram avaliadas a influência das áreas superficiais, volumes e diâmetros dos poros das matrizes de sílica no processo de confinamento das partículas semicondutoras e foi observado que as propriedades de emissão do CdTe (quantum dots, QD) dependeram das propriedades texturais das sílicas. Para ambas matrizes inorgânicas, os resultados de espectroscopia de absorção e emissão, assim como as imagens de microscopia eletrônica de transmissão de alta resolução (HRTEM), evidenciaram a formação dos materiais híbridos contendo os nanocristais de CdTe. As caracterizações eletroquímicas dos eletrodos de pasta de carbono quimicamente modificados (EQM) contendo os materiais híbridos (EQM-MS4/QD e EQM-HDL/QD) evidenciaram que a presença dos nanocristais de CdTe levaram a um aumento na sensibilidade da detecção dos analitos estudados. O eletrodo de trabalho constituído do modificador MS4/QD, após a etapa de otimização, apresentou faixa linear para a detecção de Cu2+ de 5,0 x 10-8 a 2,3 x 10-6 mol L-1 (R2 = 0,9974) e o limite de detecção (LOD) calculado foi de 6,4 x 10-8 mol L-1. O método desenvolvido mostrou-se eficiente para o monitoramento do Cu2+ em cachaça, com resultados quantitativos comparáveis aos obtidos por Espectroscopia de Absorção Atômica de Chama (FAAS). A detecção de CPX foi realizada com uso do EQM-HDL/QD, o qual sob condições de 20% de modificador, pH 6,0, tampão BR (Britton–Robinson), tempo de acumulação de 300s e velocidade de varredura de 20 mV s-1, apresentou, na faixa de 2,5 x 10-8 - 1,2 x 10-5 mol L-1 (R2 = 0,9970), uma sensibilidade de LOD = 4,2 x 10-8 mol L-1 e limite de quantificação (LOQ) de 1,3 x 10-7 mol L-1, precisão de 3,0%, recuperação de 94,0% e seletividade satisfatória na presença de alguns interferentes. Testes de determinação de CPX em comprimidos comerciais de 500 mg de ciprofloxacina evidenciaram a aplicabilidade do método.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESSão Cristóvão, SEporQuímicaSílicaHidróxidosNanocristaisTelureto de cádmioSensores eletroquímicosCobreCiprofloxacinaSílicas mesoporosasHidróxidos duplos lamelaresNanocristais de CdTeSensores eletroquímicosCobreCiprofloxacinaMesoporous silicasLamellar double hydroxidesCdTe nanocrystalsElectrochemical sensorsCopperCiprofloxacinEstudos de aplicações eletroquímicas de nanocristais semicondutores de CdTe crescidos em matrizes inorgânicasElectrochemical applications study of CdTe semiconductor nanocrystals grown on inorganic matricesinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisPós-Graduação em QuímicaUFSreponame:Repositório Institucional da UFSinstname:Universidade Federal de Sergipe (UFS)instacron:UFSinfo:eu-repo/semantics/openAccessTEXTSANNY_WEDJA_M_M_CARVALHO.pdf.txtSANNY_WEDJA_M_M_CARVALHO.pdf.txtExtracted texttext/plain221991https://ri.ufs.br/jspui/bitstream/riufs/11004/3/SANNY_WEDJA_M_M_CARVALHO.pdf.txt55da21148855cb935e7c51a8f47b7626MD53THUMBNAILSANNY_WEDJA_M_M_CARVALHO.pdf.jpgSANNY_WEDJA_M_M_CARVALHO.pdf.jpgGenerated Thumbnailimage/jpeg1425https://ri.ufs.br/jspui/bitstream/riufs/11004/4/SANNY_WEDJA_M_M_CARVALHO.pdf.jpgb054a40ea5659acd81e21346531679edMD54LICENSElicense.txtlicense.txttext/plain; charset=utf-81475https://ri.ufs.br/jspui/bitstream/riufs/11004/1/license.txt098cbbf65c2c15e1fb2e49c5d306a44cMD51ORIGINALSANNY_WEDJA_M_M_CARVALHO.pdfSANNY_WEDJA_M_M_CARVALHO.pdfapplication/pdf5381475https://ri.ufs.br/jspui/bitstream/riufs/11004/2/SANNY_WEDJA_M_M_CARVALHO.pdffec6b851dd59cccb151cc31e9ee9b553MD52riufs/110042019-04-23 16:35:11.318oai:ufs.br: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Repositório InstitucionalPUBhttps://ri.ufs.br/oai/requestrepositorio@academico.ufs.bropendoar:2019-04-23T19:35:11Repositório Institucional da UFS - Universidade Federal de Sergipe (UFS)false |
dc.title.pt_BR.fl_str_mv |
Estudos de aplicações eletroquímicas de nanocristais semicondutores de CdTe crescidos em matrizes inorgânicas |
dc.title.alternative.por.fl_str_mv |
Electrochemical applications study of CdTe semiconductor nanocrystals grown on inorganic matrices |
title |
Estudos de aplicações eletroquímicas de nanocristais semicondutores de CdTe crescidos em matrizes inorgânicas |
spellingShingle |
Estudos de aplicações eletroquímicas de nanocristais semicondutores de CdTe crescidos em matrizes inorgânicas Carvalho, Sanny Wedja Melo Machado de Química Sílica Hidróxidos Nanocristais Telureto de cádmio Sensores eletroquímicos Cobre Ciprofloxacina Sílicas mesoporosas Hidróxidos duplos lamelares Nanocristais de CdTe Sensores eletroquímicos Cobre Ciprofloxacina Mesoporous silicas Lamellar double hydroxides CdTe nanocrystals Electrochemical sensors Copper Ciprofloxacin |
title_short |
Estudos de aplicações eletroquímicas de nanocristais semicondutores de CdTe crescidos em matrizes inorgânicas |
title_full |
Estudos de aplicações eletroquímicas de nanocristais semicondutores de CdTe crescidos em matrizes inorgânicas |
title_fullStr |
Estudos de aplicações eletroquímicas de nanocristais semicondutores de CdTe crescidos em matrizes inorgânicas |
title_full_unstemmed |
Estudos de aplicações eletroquímicas de nanocristais semicondutores de CdTe crescidos em matrizes inorgânicas |
title_sort |
Estudos de aplicações eletroquímicas de nanocristais semicondutores de CdTe crescidos em matrizes inorgânicas |
author |
Carvalho, Sanny Wedja Melo Machado de |
author_facet |
Carvalho, Sanny Wedja Melo Machado de |
author_role |
author |
dc.contributor.author.fl_str_mv |
Carvalho, Sanny Wedja Melo Machado de |
dc.contributor.advisor1.fl_str_mv |
Gimenez, Iara de Fátima |
dc.contributor.advisor-co1.fl_str_mv |
Sussuchi, Eliana Midori |
contributor_str_mv |
Gimenez, Iara de Fátima Sussuchi, Eliana Midori |
dc.subject.por.fl_str_mv |
Química Sílica Hidróxidos Nanocristais Telureto de cádmio Sensores eletroquímicos Cobre Ciprofloxacina Sílicas mesoporosas Hidróxidos duplos lamelares Nanocristais de CdTe Sensores eletroquímicos Cobre Ciprofloxacina |
topic |
Química Sílica Hidróxidos Nanocristais Telureto de cádmio Sensores eletroquímicos Cobre Ciprofloxacina Sílicas mesoporosas Hidróxidos duplos lamelares Nanocristais de CdTe Sensores eletroquímicos Cobre Ciprofloxacina Mesoporous silicas Lamellar double hydroxides CdTe nanocrystals Electrochemical sensors Copper Ciprofloxacin |
dc.subject.eng.fl_str_mv |
Mesoporous silicas Lamellar double hydroxides CdTe nanocrystals Electrochemical sensors Copper Ciprofloxacin |
description |
In the present work, CdTe nanocrystals were synthesized on inorganic matrices of mesoporous silicas (MS) and lamellar hydroxides (HDL) with the objective of developing efficient and selective methods for the electrochemical detection of copper and ciprofloxacin (CPX). For the mesoporous samples, made through different synthesis methodologies, were evaluated the influence of the surface area, volumes and pore diameters of the silica matrices on the confinement process of the semiconductor particles and it was observed that the emission properties of CdTe (quantum dots, QD) depends on the texture properties of the silicas. For both inorganic matrices, results of absorption and emission spectroscopy, as well as high-resolution transmission electron microscopy images (HRTEM), evidenced a formation of hybrid materials containing CdTe nanocrystals. The electrochemical characterization of the chemically modified carbon electrodes (EQM) containing the compounds (EQM-MS4/QD and EQM-HDL/QD) show that the presence of CdTe nanocrystals, leads to an increase in the detection sensibility toward the studied analytes. After the optimization step, the working electrode made up using the modifier MS4/QD responded to a linear Cu2+ detection of 5.0 x 10-8 to 2.3 x 10-6 mol L-1 (R2 = 0,9974) and the calculated limit of detection (LOD) was 6.4 x 10-8 mol L-1. The method developed was efficient for the monitoring of Cu2+ in the sugarcane liquor, being compared with the outcomes from Flame atomic absorbtion spectroscopy (FAAS). The detection of CPX was made EQM-HDL/QD, with 20% of modifier, pH 6.0, BR buffer (Britton-Robinson), accumulation time of 300 s and scan rate of 20 mV s-1, in the range 2.5 x 10-8 to 1.2 x 10-5 mol L-1 (R2 = 0.9970), a sensitivity of LOD = 4.2 x 10-8 mol L-1 and limit of quantification (LOQ) of 1.3 x 10-7 mol L-1, accuracy of 3.0%, recovery of 94.0% and satisfactory selectivity in the presence of some interferents. Tests of CPX determination in commercial capsules of 500 mg of ciprofloxacin showed the applicability of the method. |
publishDate |
2019 |
dc.date.accessioned.fl_str_mv |
2019-04-23T19:35:11Z |
dc.date.available.fl_str_mv |
2019-04-23T19:35:11Z |
dc.date.issued.fl_str_mv |
2019-02-20 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
format |
doctoralThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
CARVALHO, Sanny Wedja Melo Machado de. Estudos de aplicações eletroquímicas de nanocristais semicondutores de CdTe crescidos em matrizes inorgânicas. 2019. 147 f. Tese (Doutorado em Química) - Universidade Federal de Sergipe, São Cristóvão, SE, 2019. |
dc.identifier.uri.fl_str_mv |
http://ri.ufs.br/jspui/handle/riufs/11004 |
identifier_str_mv |
CARVALHO, Sanny Wedja Melo Machado de. Estudos de aplicações eletroquímicas de nanocristais semicondutores de CdTe crescidos em matrizes inorgânicas. 2019. 147 f. Tese (Doutorado em Química) - Universidade Federal de Sergipe, São Cristóvão, SE, 2019. |
url |
http://ri.ufs.br/jspui/handle/riufs/11004 |
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por |
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Pós-Graduação em Química |
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UFS |
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