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Desenvolvimento de uma célula de biocombustível enzimática de colesterol/O2 feito em papel
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Abstract(s)
A crescente necessidade de soluções energéticas sustentáveis tem impulsionado a investigação no campo das células de biocombustível enzimáticas (EBFCs), dispositivos bio eletroquímicos que aliam a conversão de energia química em eletricidade à deteção seletiva de analitos fisiológicos. No presente trabalho, foi desenvolvido um protótipo de célula de biocombustível enzimática, construída sobre um substrato de papel modificado, com o objetivo de permitir a deteção seletiva do colesterol – um biomarcador de relevância clínica no diagnóstico e monitorização de doenças cardiovasculares. A célula proposta assenta na utilização da enzima colesterol oxidase (ChOx) como biocatalisador no bio ânodo e da bilirrubina oxidase (BOx) no bio cátodo, integrando elétrodos
serigrafados de ouro modificados com nanotubos de carbono de paredes múltiplas (MWCNT) com e sem recurso a mediador redox de eletrões (tionina) e agentes de ligação para promover uma melhor imobilização e transferência de eletrões. A caracterização eletroquímica do bio ânodo e bio cátodo foi realizada como biossensores para colesterol e oxigénio respetivamente através das técnicas de voltametria cíclica e de amperometria, permitindo avaliar a eficiência da transferência eletrónica, a sensibilidade do sistema à presença de cada substrato A célula de biocombustível colesterol/O2 foi depois caracterizada pela conjugação do
bio ânodo e bio cátodo através de voltametria de varrimento linear obtendo-se as curvas de polarização e consequentemente de potência. O potencial de circuito aberto (OCP) da célula de biocombustível atingiu um valor de 0,36 V e uma potencia máxima de 0,41 μW antevendo-se o seu potencial uso como biossensor energeticamente autoalimentado para determinação de colesterol. Este sistema é promissor para aplicações biomédicas portáteis, como a monitorização não invasiva de biomarcadores, uma vez que incorpora materiais com baixo custo e alto desempenho em transdutores mais sustentáveis. O potencial das EBFC como ferramentas analíticas inovadoras e energeticamente autónomas é reforçado por este estudo, o que promove tecnologias bio eletroquímicas sustentáveis.
The growing demand for sustainable energy solutions has driven research in the field of enzymatic biofuel cells (EBFCs), bioelectrochemical devices that combine the conversion of chemical energy into electricity with the selective detection of physiological analytes. In the present work, an enzymatic biofuel cell prototype was developed on a modified paper substrate, aimed at enabling the selective detection of cholesterol—a clinically relevant biomarker for the diagnosis and monitoring of cardiovascular diseases. The proposed cell is based on the use of the enzyme cholesterol oxidase (ChOx) as the biocatalyst at the bioanode and bilirubin oxidase (BOx) at the biocathode, incorporating screenprinted gold electrodes modified with multi-walled carbon nanotubes (MWCNTs), with and without the use of an electron transfer mediator (thionine) and binding agents to promote improved enzyme immobilization and electron transfer. Electrochemical characterization of the bioanode and biocathode as biosensors for cholesterol and oxygen, respectively, was carried out using cyclic voltammetry and amperometry techniques, allowing the evaluation of electron transfer efficiency and system sensitivity to each substrate. The cholesterol/O₂ biofuel cell was subsequently characterized by combining the bioanode and biocathode through linear sweep voltammetry, yielding polarization and corresponding power curves. The open circuit potential (OCP) of the biofuel cell reached 0.36 V, with a maximum power output of 0.41 μW, indicating its potential as a self-powered biosensor for cholesterol determination. This system shows promise for portable biomedical applications, such as non-invasive biomarker monitoring, as it incorporates low-cost, high-performance materials in more sustainable transducers. The potential of EBFCs as innovative and energy-autonomous analytical tools is reinforced by this study, promoting the development of sustainable bioelectrochemical technologies.
The growing demand for sustainable energy solutions has driven research in the field of enzymatic biofuel cells (EBFCs), bioelectrochemical devices that combine the conversion of chemical energy into electricity with the selective detection of physiological analytes. In the present work, an enzymatic biofuel cell prototype was developed on a modified paper substrate, aimed at enabling the selective detection of cholesterol—a clinically relevant biomarker for the diagnosis and monitoring of cardiovascular diseases. The proposed cell is based on the use of the enzyme cholesterol oxidase (ChOx) as the biocatalyst at the bioanode and bilirubin oxidase (BOx) at the biocathode, incorporating screenprinted gold electrodes modified with multi-walled carbon nanotubes (MWCNTs), with and without the use of an electron transfer mediator (thionine) and binding agents to promote improved enzyme immobilization and electron transfer. Electrochemical characterization of the bioanode and biocathode as biosensors for cholesterol and oxygen, respectively, was carried out using cyclic voltammetry and amperometry techniques, allowing the evaluation of electron transfer efficiency and system sensitivity to each substrate. The cholesterol/O₂ biofuel cell was subsequently characterized by combining the bioanode and biocathode through linear sweep voltammetry, yielding polarization and corresponding power curves. The open circuit potential (OCP) of the biofuel cell reached 0.36 V, with a maximum power output of 0.41 μW, indicating its potential as a self-powered biosensor for cholesterol determination. This system shows promise for portable biomedical applications, such as non-invasive biomarker monitoring, as it incorporates low-cost, high-performance materials in more sustainable transducers. The potential of EBFCs as innovative and energy-autonomous analytical tools is reinforced by this study, promoting the development of sustainable bioelectrochemical technologies.
Description
Keywords
Enzymatic biofuel cell cholesterol electrochemical biosensor electrode carbon nanotubes direct electron transfer Célula de biocombustível enzimática Colesterol Biossensor eletroquímico Elétrodo Nanotubos de carbono