Desenvolvimento de biossensores amperométricos à base de acetilcolinesterase para detecção de microcistinas

Detalhes bibliográficos
Ano de defesa: 2016
Autor(a) principal: Souto, Laiane Araújo da Silva lattes
Orientador(a): NUNES, Gilvanda Silva
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal do Maranhão
Programa de Pós-Graduação: PROGRAMA DE PÓS-GRADUAÇÃO EM QUÍMICA/CCET
Departamento: DEPARTAMENTO DE TECNOLOGIA QUÍMICA/CCET
País: Brasil
Palavras-chave em Português:
Área do conhecimento CNPq:
Link de acesso: http://tedebc.ufma.br:8080/jspui/handle/tede/1572
Resumo: Microcystin (MC-LR) are a class hepatotoxins produced by cyanobacteria in surface water. scientific records show that the MC-LR, inhibits the action of intracellular proteins, alkaline phosphatases, but has also been proven to increase the enzyme acetylcholinesterase activity (AChE) by the MC-LR action. Therefore, this study aimed to develop biosensors amperometric based AChE enzyme for indirect detection of MC-LR. For construction of the working electrode, a powder graphite paste containing hidroxicetilcelulose (HEC), bovine serum albumin (BSA) and glutaraldehyde (Glu) was prepared. The slurry was incorporated into the AChE enzyme extracted bovine erythrocyte (EB) and electric eel (EE) as well as enzymes derived from Drosophila melanogaster was tested genetically modificadas.Também enzyme butyrylcholinesterase (BChE) obtained from human serum. A portion of the sensitive paste was deposited in the screen-printed sensor working electrode and performed characterization tests involving differential pulse voltammetry and cyclic voltammetry. cronoamperométricas readings were performed and the percentage built on activation curves (% RA) as a function of the concentration of MC-LR. Some operating conditions, such as working potential, electrochemical mediator, medium pH and substrate concentration, were optimized. enzyme activation assays showed that the EE-AChE enzyme showed best results percent relative activation (% RA) (> 10%), these values being directly proportional to the concentration of MC-LR. The biosensor developed proved accurate (CV ~ 8.32%), sensitive (Ld 0.27 μg .L-1 and LQ 0.91 μg .L-1) and accurate (recovery rates varying from 73 to 105%). The initial study proved to be the right biosensor to verify the presence of MC-LR in aquatic environments, this being then used in monitoring pollutant seven points of Bacanga River, an important aquatic ecosystem of San Luis, MA. The results indicated that there was no significant contamination.