$$\newcommand{\bra}[1]{\left<#1\right|}\newcommand{\ket}[1]{\left|#1\right>}\newcommand{\bk}[2]{\left<#1\middle|#2\right>}\newcommand{\bke}[3]{\left<#1\middle|#2\middle|#3\right>}$$
X
INFORMAÇÕES SOBRE DIREITOS AUTORAIS


As obras disponibilizadas nesta Biblioteca Digital foram publicadas sob expressa autorização dos respectivos autores, em conformidade com a Lei 9610/98.

A consulta aos textos, permitida por seus respectivos autores, é livre, bem como a impressão de trechos ou de um exemplar completo exclusivamente para uso próprio. Não são permitidas a impressão e a reprodução de obras completas com qualquer outra finalidade que não o uso próprio de quem imprime.

A reprodução de pequenos trechos, na forma de citações em trabalhos de terceiros que não o próprio autor do texto consultado,é permitida, na medida justificada para a compreeensão da citação e mediante a informação, junto à citação, do nome do autor do texto original, bem como da fonte da pesquisa.

A violação de direitos autorais é passível de sanções civis e penais.
Coleção Digital

Avançada


Estatísticas | Formato DC | MARC |



Título: DEVELOPMENT OF ELECTRO-ANALYTICAL METHODS USING SENSORS MODIFIED WITH NANOMATERIALS FOR DETERMINATION OF PRIMAQUINE, INHHQ, THIOMERSAL AND CREATININE
Autor: MARLIN JEANNETTE PEDROZO PEÑAFIEL
Instituição: PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO - PUC-RIO
Colaborador(es):  RICARDO QUEIROZ AUCELIO - ADVISOR
Nº do Conteudo: 51025
Catalogação:  28/12/2020 Idioma(s):  ENGLISH - UNITED STATES
Tipo:  TEXT Subtipo:  THESIS
Natureza:  SCHOLARLY PUBLICATION
Nota:  Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio.
Referência [pt]:  https://www.maxwell.vrac.puc-rio.br/colecao.php?strSecao=resultado&nrSeq=51025@1
Referência [en]:  https://www.maxwell.vrac.puc-rio.br/colecao.php?strSecao=resultado&nrSeq=51025@2
Referência DOI:  https://doi.org/10.17771/PUCRio.acad.51025

Resumo:
The goal of this work was the development of electro-analytical methods using electrodes modified with carbon-based nanomaterials for determination of analytes of biological (creatinine) and pharmacological interest (primaquine, INHHQ, thiomersal). The determination of primaquine (antimalarial) and INHHQ (potential drug for treatment of neurodegenerative diseases) was proposed using glassy carbon (GC) electrode modified with multi-walled carbon nanotubes (MWCNTs) that promoted significant improvement in faradaic current and better peak resolution obtained using square-wave voltammetry (SWV) in Britton-Robinson (BR) buffer 0.02 mol L-1; pH 7.00 and KCl (0.25 mol L-1). Although several methods to quantify primaquine are reported, many of these depend on procedure considered complex and laborious, therefore, the proposed GC modification using MWCNTs is comparatively easy, leading to a robust modification that produce repetitive results also providing amplification of the electrochemical signal due to the increased active area and improved electron-transfer rate. The GC/MWCNTs also provided, when working on a proper pH, higher resolution in detecting the different electrochemical steps involved in the redox process of primaquine. The electrode enabled limit of detection (LOD) of 28 nmol L-1 for primaquine and, when associated with a simple developed procedure, relying of liquid-liquid extraction (LLE) and thin-layer chromatography (TLC), it was achieved the selectivity and the capability to determine the lower levels expected in urine samples. In the case of INHHQ, a method for quantification by SWV was reported for the first time. In addition to the use of GC/MWCNTs electrode, a previous TLC procedure, enabled the selectivity required to determine INHHQ in brain tissue from Wistar rats. The LOD was 0.85 mol L-1 and the linear dynamic range covered two orders of magnitude (10-6 to 10-5 mol L-1). Graphene quantum dots (GQDs) was chosen to chemically modify electrodes used to determine thiomersal and creatinine. GQDs are nanometric fragments of graphene (present in dispersions as monolayer, few layer or multilayer) where electron transport is confined in their dimensions. GQDs are carbon-based structure that are bio-compatible and present low toxicity. The research presents a new approach for the determination of thimerosal (preservative in vaccines and cosmetics) in influenza vaccines using GQDs as a modifier of the GC electrode and exploring the synergistic effect between GQDs, visible radiation and the applied potential difference. This system promotes thiomersal oxidation, producing a significant increase in response (Hg/Hg2 positive redox pair) in terms of current intensity using SWV and BR buffer (0.02 mol L-1; pH 4.00 with KCl at 0.25 mol L-1). The LOD was 0.85 μmol L-1 with linear dynamic range covering three orders of magnitude (10-6 to 10-4 mol L-1). For creatinine, a biomarker for the renal dysfunction, a GQDs-copper composite was used to modify a gold electrode. Determination of creatinine was made using SWV (BR buffer 0.02 mol L-1; pH 4.00 with KCl at 0.25 mol L-1). The method relied on the decreasing of the Cu2+/Cu oxidation peak in the presence of creatinine, enabling LOD of 50 nmol L-1 and linear dynamic range covering three orders of magnitude (10-6 to 10-4 mol L-1). The SWV response of creatinine was attributed to the formation of creatinine-Cu2 positive complex being reasonably selective towards this analyte. All procedures developed by voltammetry were adequately compared with reference methods, being statistically compatible.

Descrição Arquivo
COMPLETE  PDF
Logo maxwell Agora você pode usar seu login do SAU no Maxwell!!
Fechar Janela



* Esqueceu a senha:
Senha SAU, clique aqui
Senha Maxwell, clique aqui