Desenvolvimento de quimioresistor baseado em filme polimérico de Bismarck Brown Y para monitoramento de oxigênio mitocondrial
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Data
2019-02-08
Autores
Oliveira, André Olean [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A presente dissertação apresenta os estudos e os esforços dedicados ao desenvolvimento de uma plataforma sensorial eletroquímica para monitoramento em tempo real de oxigênio dissolvido, baseando-se na alteração de resistência elétrica do material nanocompósito de azopolímero e óxido de grafeno, para aplicações em meio biológico. O filme foi construído através de técnica de eletropolimerização sobre eletrodo de óxido de estanho dopado com flúor (FTO), formando um filme fino nanoestruturado com camadas alternadas de óxido de grafeno reduzido e o azopolímero de Bismark Brown Y (poli(azo-BBY)-rGO). A morfologia do filme nanocompósito foi analisada por microscopia eletrônica de varredura (MEV) e microscopia de força atômica (AFM) revelando uma superfície rugosa e uniforme. A caracterização eletroquímica da plataforma sensorial foi realizada por técnica de espectroscopia de impedância eletroquímica (EIE), onde foram investigados os fenômenos interfaciais. Através de EIE foi verificado uma diminuição do valor de resistência de transferência de carga do sistema (ΔR = 47,05 k) quando na presença de solução saturada de oxigênio dissolvido. O sensor quimioresistor de poli(azo-BBY)-rGO demonstrou estabilidade nas respostas em uma ampla faixa de pH e apresentou resposta linear na faixa de concentração de 1,17 x10-5 a 1,02 x10-3 com limite de detecção de 3,55 x10-7 mol L-1 a pH 7,4. Por fim, a plataforma sensorial foi aplicada no monitoramento do consumo de oxigênio mitocondrial em tecido retirado do músculo esquelético (gastrocnêmico) de ratos submetidos a fumo passivo e exercício resistido, permitindo obter a capacidade respiratória dos complexos que constituem a cadeia transportadora de elétrons
The present dissertation presents the studies and the efforts dedicated to the development of an electrochemical sensing platform for real time monitoring of dissolved oxygen, based on the alteration of electrical resistance of the azopolymer nanocomposite material and graphene oxide for biological applications. The film was constructed by electropolymerization technique on fluoride-doped tin oxide (FTO), forming a nanostructured thin film with alternating layers of reduced graphene oxide and Bismark Brown Y (poly(azo-BBY)-rGO). The morphology of the nanocomposite film was analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealing a rough and uniform surface. The electrochemical characterization of the sensory platform was performed by electrochemical impedance spectroscopy (EIS), where the interfacial phenomena were investigated. A decrease in the load transfer resistance value of the system (ΔR = 47.05 k) was observed in the presence of saturated solution of dissolved oxygen. The poly(azo-BBY)-rGO chemoresistor sensor demonstrated stability in the responses over a wide pH range and showed a linear response in the concentration range of 1.17 x10-5 to 1.02 x10-3 with detection limit of 3.55 x10-7 mol L-1 at pH 7.4. Finally, the sensorial platform was applied to the monitoring of the mitochondrial oxygen consumption in tissue removed from the skeletal muscle (gastrocnemius) of passive smoking and resistance exercise, allowing to obtain the respiratory capacity of the complexes that constitute the electron transport chain.
The present dissertation presents the studies and the efforts dedicated to the development of an electrochemical sensing platform for real time monitoring of dissolved oxygen, based on the alteration of electrical resistance of the azopolymer nanocomposite material and graphene oxide for biological applications. The film was constructed by electropolymerization technique on fluoride-doped tin oxide (FTO), forming a nanostructured thin film with alternating layers of reduced graphene oxide and Bismark Brown Y (poly(azo-BBY)-rGO). The morphology of the nanocomposite film was analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealing a rough and uniform surface. The electrochemical characterization of the sensory platform was performed by electrochemical impedance spectroscopy (EIS), where the interfacial phenomena were investigated. A decrease in the load transfer resistance value of the system (ΔR = 47.05 k) was observed in the presence of saturated solution of dissolved oxygen. The poly(azo-BBY)-rGO chemoresistor sensor demonstrated stability in the responses over a wide pH range and showed a linear response in the concentration range of 1.17 x10-5 to 1.02 x10-3 with detection limit of 3.55 x10-7 mol L-1 at pH 7.4. Finally, the sensorial platform was applied to the monitoring of the mitochondrial oxygen consumption in tissue removed from the skeletal muscle (gastrocnemius) of passive smoking and resistance exercise, allowing to obtain the respiratory capacity of the complexes that constitute the electron transport chain.
Descrição
Palavras-chave
Sensor quimioresistor, Filme nanocompósito, Respiração mitocondrial, Azopolímeros Condutores, Eletroquímica, Chemiresistor sensor, Nanocomposite film, Mitochondrial respiration, Azo polymer