Desenvolvimento de sensores eletroquímicos baseados em nanomateriais de carbono para detecção de diquat em amostras ambientais e tadalafila em amostras farmacêuticas

Detalhes bibliográficos
Ano de defesa: 2019
Autor(a) principal: Zambianco, Naiara Alana
Orientador(a): Janegitz, Bruno Campos lattes
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal de São Carlos
Câmpus São Carlos
Programa de Pós-Graduação: Programa de Pós-Graduação em Biotecnologia - PPGBiotec
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Palavras-chave em Inglês:
Área do conhecimento CNPq:
Link de acesso: https://repositorio.ufscar.br/handle/20.500.14289/11156
Resumo: In this work two electrochemical sensors were proposed based on carbon nanomaterials for detection of diquat and tadalafil. For the first was proposed a surface modification of glassy carbon electrode with manioc starch and nanodiamonds dispersion. The other sensor was based on a film of vertically aligned carbon nanotubes with a copper plate like substrate. The glassy carbon electrode modified with nanodiamonds and manioc starch film was characterized electrochemical and morphological characteristics through techniques such as cyclic voltammetry, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and x-ray diffraction to understand the electrochemical behavior of the film. Many techniques were analyzed regarding the behavior and quantification of diquat, however, the technique that presented the highest peak current was the square wave voltammetry. After the choice of chemical and electrochemical parameters, was constructed an analytical curve with a linear range of 5.0×10−7 to 4.6×10−5 mol L −1. The limit of detection was 1.1×10−7 mol L− 1. Water samples fortified with diquat were analyzed. In comparison to the works, the glassy carbon electrode modified with nanodiamonds and manioc starch film has a good linear range and a low limit of detection. For the second electrode was chosen for morphological characterization through images obtained by scanning electron microscopy, as well as transmission; in addition to electrochemical characterizations acquired by cyclic voltammetry from the potassium ferri/ferro-cyanide like redox probe. In order to study the electrochemistry of tadalafil were analyzed some voltammetric techniques like cyclic voltammetry, linear sweep voltammetry, differential pulse voltammetry and square wave voltammetry, especially the linear sweep voltammetry in which the device reached the highest anodic peak current. Optimizing the parameters, the analytical determination of tadalafil comprised a linear concentration range of 0.85 to 8.9×10−6 mol L−1 where the limit of detection was 7.8×10−8 mol L−1. The samples selected for validation of the device were drugs obtained from pharmacies in the city of Araras being a generic and a manipulated drug.