Desenvolvimento de um sensor quimiocapacitor baseado em polímeros redox molecularmente impressos para detecção e quantificação de albumina sérica humana
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Data
2023-01-25
Autores
Trevizan, Heitor Furlan
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A albumina sérica humana (ASH) é uma proteína globular encontrada em maior concentração no plasma sanguíneo. Valores subnormais de albumina no organismo podem indicar distúrbios metabólicos, como desnutrição, biomarcador de câncer e de doença cardiovascular, renal e hepática. Os polímeros molecularmente impressos (PMI) apresentam diversas vantagens para uma plataforma eletroquímica no sensoriamento de biomoléculas como baixo custo, seletividade e simplicidade. Por esse motivo, foi desenvolvimento e caracterizado um sensor impedimétrico/ capacitivo baseado em polímero molecularmente impresso, utilizando o Bismarck Brown Y como monômero redox para detecção e quantificação de albumina sérica. O filme PMI foi eletrodepositado na superfície do eletrodo de óxido de estanho dopado com flúor por eletropolimerização do monômero Bismarck Brown Y na presença de albumina como molécula molde. A morfologia dos filmes formado foi analisada por microscopia eletrônica de varredura, revelando filmes homogêneos com pequenos aglomerados. A caracterização eletroquímica da plataforma sensorial foi realizada por técnica de espectroscopia de impedância/ capacitância eletroquímica (EIE), onde foram investigados os fenômenos interfaciais. Através de EIE e ECE foi verificado um aumento do valor de resistência de transferência de carga do sistema (ΔR = 76,8 kΩ cm2) e uma diminuição da capacitância redox em 0,90 µF cm-2 quando testado na presença de albumina. Foi realizada a otimização de parâmetros como velocidade de varredura, número de ciclos e pH na etapa de eletropolimerização. O sensor de PMI-poli(azo-Bismarck Y) respondeu a uma faixa linear de concentração de 0,25 – 1,5 ng mL-1 com limite detecção de 0,24 ng mL-1 para capacitância real e 0,22 ng mL-1 capacitância imaginária em pH 7,3. A reprodutibilidade foi estudada usando sete sensores PMI-poli(azo-Bismarck Y) preparados independentemente para a detecção de albumina (0,5 ng mL−1). Como resultado, o desvio padrão relativo (DPR) da resposta de impedância/capacitância foi de 8,98%. Portanto, os sensores exibem boa reprodutibilidade. Após 14 dias, o DPR do sensor foi de 9,81%, indicando excelente estabilidade. O desempenho de reconhecimento seletivo do sensor foi investigado com espécies concomitantes que possivelmente atuam como interferentes no fluido biológico. O sensor MIP apresentou alta seletividade para adsorção de ASH em comparação com outras proteínas e aminoácidos.
The human serum albumin (HSA) is a globular protein found in highest concentration in blood plasma. Subnormal values of albumin in the body can indicate metabolic disorders, such as malnutrition, a biomarker of cancer and cardiovascular, renal and hepatic diseases. Molecularly imprinted polymers (MIP) have several advantages for an electrochemical platform for sensing biomolecules such as low cost, selectivity and simplicity. For this reason, develop and characterize an impedimetric/capacitive sensor based on molecularly imprinted polymers, using Bismarck Brown Y as a redox monomer for detection and quantification of serum albumin. The PMI film was electrodeposited on the surface of the fluorine-doped tin oxide electrode by electropolymerization of Bismarck Brown Y monomer in the presence of albumin as a template molecule. The morphology of the formed films was analyzed by scanning electron microscopy, revealing homogeneous films with small clusters. The electrochemical characterization of the sensory platform was performed by electrochemical impedance/capacitance (EIE) spectroscopy technique, where the interfacial phenomena were investigated. Through EIE and ECE, an increase in the load transfer resistance value of the system (ΔR = 76.8 kΩ cm2) and a decrease in redox capacitance by 0.90 µF cm-2 when in the presence of albumin was verified. The optimization of parameters such as scan rate, number of cycles and pH was performed in the electropolymerization step of the molecularly printed film. The PMI-poly(azoBBY)-ASH sensor responded to a linear concentration range of 0.50 – 1.5 ng mL-1 with detection limit of 0.26 ng mL-1 for true capacitance and 0.24 ng mL-1 imaginary capacitance at pH 7.3. Reproducibility was studied using seven independently prepared poly(azo-BBY)-MIP sensors for the detection of albumin (0.5 ng mL−1). As a result, the RSD relative standard deviation of the impedance/capacitance response was less than 8,98%. Therefore, poly(azo-BBY)-MIP sensors exhibit good reproducibility. After 14 days, the RSD of the poly(azo-BBY)-MIP sensor was 9.81%, indicating excellent stability. The selective recognition performance of the sensor was investigated with concomitant species that possibly act as interferents in biological fluid. The MIP sensor showed high selectivity for ASH adsorption compared to other proteins and aminoacids.
The human serum albumin (HSA) is a globular protein found in highest concentration in blood plasma. Subnormal values of albumin in the body can indicate metabolic disorders, such as malnutrition, a biomarker of cancer and cardiovascular, renal and hepatic diseases. Molecularly imprinted polymers (MIP) have several advantages for an electrochemical platform for sensing biomolecules such as low cost, selectivity and simplicity. For this reason, develop and characterize an impedimetric/capacitive sensor based on molecularly imprinted polymers, using Bismarck Brown Y as a redox monomer for detection and quantification of serum albumin. The PMI film was electrodeposited on the surface of the fluorine-doped tin oxide electrode by electropolymerization of Bismarck Brown Y monomer in the presence of albumin as a template molecule. The morphology of the formed films was analyzed by scanning electron microscopy, revealing homogeneous films with small clusters. The electrochemical characterization of the sensory platform was performed by electrochemical impedance/capacitance (EIE) spectroscopy technique, where the interfacial phenomena were investigated. Through EIE and ECE, an increase in the load transfer resistance value of the system (ΔR = 76.8 kΩ cm2) and a decrease in redox capacitance by 0.90 µF cm-2 when in the presence of albumin was verified. The optimization of parameters such as scan rate, number of cycles and pH was performed in the electropolymerization step of the molecularly printed film. The PMI-poly(azoBBY)-ASH sensor responded to a linear concentration range of 0.50 – 1.5 ng mL-1 with detection limit of 0.26 ng mL-1 for true capacitance and 0.24 ng mL-1 imaginary capacitance at pH 7.3. Reproducibility was studied using seven independently prepared poly(azo-BBY)-MIP sensors for the detection of albumin (0.5 ng mL−1). As a result, the RSD relative standard deviation of the impedance/capacitance response was less than 8,98%. Therefore, poly(azo-BBY)-MIP sensors exhibit good reproducibility. After 14 days, the RSD of the poly(azo-BBY)-MIP sensor was 9.81%, indicating excellent stability. The selective recognition performance of the sensor was investigated with concomitant species that possibly act as interferents in biological fluid. The MIP sensor showed high selectivity for ASH adsorption compared to other proteins and aminoacids.
Descrição
Palavras-chave
Albumina sérica humana, Polímero molecularmente impresso, Molde molecular, Espectroscopia impedância/ Capacitância eletroquímica, Human serum albumin, Molecularly imprinted polymer, Molecular template, Electrode