Genossensor para a detecção de Alicyclobacillus acidoterrestris baseado em nanocompósito polimérico

Detalhes bibliográficos
Ano de defesa: 2017
Autor(a) principal: Flauzino, José Manuel Rodrigueiro
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal de Uberlândia
Brasil
Programa de Pós-graduação em Genética e Bioquímica
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Link de acesso: https://repositorio.ufu.br/handle/123456789/19909
http://dx.doi.org/10.14393/ufu.di.2017.1
Resumo: In this work a polymeric nanocomposite of reduced graphene oxide and poly (3- hydroxybenzoic acid) was developed for the modification of graphite electrodes, aiming the development of a genossensor for the detection of the Alicyclobacillus acidoterrestris genomic DNA. This bacterium is associated with the spoilage of acidic juices, such as orange juice, of which Brazil is the largest producer in the world. In this context, biosensors appear as fast and easy to handle detection devices, with great potential for use throughout the juice production chain. For the construction of the genosensor, graphene oxide was produced by the modified Hummers method, dripped onto the surface of the graphite electrode and reduced electrochemically. The 3-hydroxybenzoic acid was electropolymerized on this surface containing the nanomaterial. Analyzes by infrared spectroscopy and cyclic voltammetry proved the reduction of graphene oxide. In addition, the electrochemical analysis showed that the nanocomposite produced has higher electronic properties than the polymeric film. On this nanocomposite, an oligonucleotide probe ALIC1, specific for A. acidoterrestris, was immobilized, and was used to detect a complementary target oligonucleotide ALIC2, both directly and indirectly, the latter using the Hoechst 33258 double strand DNA intercalator, by the differential pulse voltammetry (DPV) technique. A cell lysate obtained from an A. acidoterrestris culture was also indirectly detected by DPV, and a calibration curve was constructed. The proposed genosensor presented a limit of detection of 174 ng mL-1 and limit of quantification of 581 ng mL-1, being able to detect the genomic DNA in a real sample of orange juice and to distinguish between the samples of A acidoterrestris and Escherichia coli. Thus, this bioelectrode presents as the first platform of electrochemical detection of the genomic DNA of A. acidoterrestris in the scientific literature.