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Abstract(s)
A necessidade de desenvolver métodos rápidos e baratos, acessíveis a todos no mundo inteiro é de extrema importância, principalmente, quando se trata de melhorar as condições de saúde global. Um fator importante para a prevenção e tratamento de doenças é o seu correto diagnóstico. Os biossensores são uma ferramenta que pode vir a ser muito útil na construção de testes em point-of-care, sendo dispositivos biocompatíveis e de custo reduzido.
O objetivo deste trabalho foi desenvolver um biossensor eletroquímico para o rastreio da Doença de Alzheimer. Teve como base a deteção de um biomarcador relacionado com os processos neuro-inflamativos, a Interleucina 6 (IL-6).
Os dispositivos biossensores utilizados baseiam-se em elétrodos de carbono impressos numa base cerâmica utilizando a técnica screen-printing. O circuito elétrico destes dispositivos é feito recorrendo a uma tinta condutora de grafite, onde posteriormente é impresso sobre o elétrodo de trabalho a mistura reacional para o desenvolvimento do polímero de impressão molecular. Esta mistura consiste no analito (IL-6), no monómero (Pirrol), no agente de ligação cruzada e no iniciador radical. A modificação da superfície do elétrodo ocorreu por polimerização eletroquímica, formando um polímero condutor na sua matriz.
Foram otimizados os parâmetros de eletropolimerização e após a polimerização o analito foi removido da estrutura polimérica por ação proteolítica de um ácido. A avaliação da performance analítica do biossensor foi efetuada por técnicas eletroanalíticas. A caracterização química e morfológica da superfície dos materiais foi efetuada por análise Raman.
A resposta do biossensor observou-se numa gama de valores entre 0,02 pg/mL e 2,0 µg/mL de IL-6, o que indica que os limites de resposta se encontram dentro dos parâmetros fisiológicos pretendidos, já que para um indivíduo saudável o valor ronda os 1,6 pg/mL e num indivíduo com neuro-inflamação os 2,3 pg/mL. Obteve-se um biossensor reprodutível, com limites de deteção baixos, resposta rápida e barato.
The need to develop fast and cheap methods accessible to everyone around the world is extremely important, especially when it comes to improve global health conditions. A crucial actor for the prevention and treatment of diseases is their correct diagnosis. Biosensors printed on paper are a promising tool that can prove to be very useful in point-of-care testing, lso offering easy construction procedures and biocompatibility, at a low cost. The objective of this work is to develop an electrochemical biosensor for screening Alzheimer's disease. It is based on the detection of a biomarker associated with the neuro inflammation processes, Interleukin 6 (IL-6). The devices described herein are based on printed carbon electrodes on a ceramic upport, using screen-printing technique. The electrical circuits are designed by a conductive graphite ink and printed later on the working electrode for the development of molecular mprinting polymer. The mixture consists on the analyte (IL-6), the monomer (Pyrrol), a crosslinking agent and a radical initiator. The modification of the surface of the electrode occurred by electrochemical polymerization, forming a conductive polymer in the matrix. The electropolymerization parameters where optimized prior to polymerization. The protein was imprinted on the sensing layer by growing the polymer around IL-6 and removing it later by proteolytic action of a suitable acid. The performance of the biosensor was evaluated by electroanalytical techniques. The chemical and morphological characterization of the materials was carried by Raman analysis. The biosensor response was observed from 0.02 pg/mL to 2.0 g/mL from IL-6, indicating that the response limits are within the desired physiological parameters, since for a healthy individual the value is around 1.6 pg/mL and for an individual with neuro-inflammation is 2.3 pg/mL. Overall, the presented biosensor offers the advantages of being a low cost and reproducible biosensor, with low detection limits and fast response.
The need to develop fast and cheap methods accessible to everyone around the world is extremely important, especially when it comes to improve global health conditions. A crucial actor for the prevention and treatment of diseases is their correct diagnosis. Biosensors printed on paper are a promising tool that can prove to be very useful in point-of-care testing, lso offering easy construction procedures and biocompatibility, at a low cost. The objective of this work is to develop an electrochemical biosensor for screening Alzheimer's disease. It is based on the detection of a biomarker associated with the neuro inflammation processes, Interleukin 6 (IL-6). The devices described herein are based on printed carbon electrodes on a ceramic upport, using screen-printing technique. The electrical circuits are designed by a conductive graphite ink and printed later on the working electrode for the development of molecular mprinting polymer. The mixture consists on the analyte (IL-6), the monomer (Pyrrol), a crosslinking agent and a radical initiator. The modification of the surface of the electrode occurred by electrochemical polymerization, forming a conductive polymer in the matrix. The electropolymerization parameters where optimized prior to polymerization. The protein was imprinted on the sensing layer by growing the polymer around IL-6 and removing it later by proteolytic action of a suitable acid. The performance of the biosensor was evaluated by electroanalytical techniques. The chemical and morphological characterization of the materials was carried by Raman analysis. The biosensor response was observed from 0.02 pg/mL to 2.0 g/mL from IL-6, indicating that the response limits are within the desired physiological parameters, since for a healthy individual the value is around 1.6 pg/mL and for an individual with neuro-inflammation is 2.3 pg/mL. Overall, the presented biosensor offers the advantages of being a low cost and reproducible biosensor, with low detection limits and fast response.
Description
Keywords
Biossensor Alzheimer Interleucina-6 Pirrol Polímero de Impressão Molecular Biosensor Interleukin-6 Pyrrol Molecular Imprinted Polymers