Polímeros biomiméticos híbridos para substâncias estrogênicas visando desenvolvimento de sensores para aplicação na área biotecnológica
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Data
2017-06-06
Autores
Bergamin, Bruna [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O desenvolvimento de métodos analíticos cada vez mais seletivos e sensíveis é de grande importância para uma melhor qualidade na determinação de espécies químicas, aumentando assim a confiabilidade dos resultados obtidos. Com isso, o emprego e otimização das etapas de separação/concentração se faz necessário. O emprego de polímeros molecularmente impressos (do inglês - “Molecularly Imprinted Polymers” - MIP) tem demonstrado ser uma eficiente ferramenta analítica com grande potencialidade para minimizar as limitações das técnicas de separação/concentração tradicionalmente empregadas. No caso deste trabalho, o template utilizado será o valerato de estradiol, principalmente pela sua importância inerente na reposição hormonal feminina e por se tratar de um disruptor endócrino (hormônio) lançado ao meio ambiente sem nenhum controle. Assim a síntese do polímero para identificação do valerato de estradiol foi realizada por diferentes rotas (bulk e precipitação) através de duas vias de polimerização (termopolimerização e fotopolimerização) variando o monômero funcional (MAA, acrilonitrila, 2-vinil-piridina e 1-vinilimidazol). O MIP e NIP foram colocados, um de cada vez, em sistema soxhlet contendo metanol/ácido acético na proporção 70/30 a 60º C, para remoção da molécula impressa, através de cinco lavagens sucessivas em períodos de 24 h. Essas águas de lavagem foram analisadas utilizando espectrofotometria UV/Vis. Posteriormente com os parâmetros otimizados o polímero que apresentou melhor resultado foi modificado com nanopartículas magnéticas (core@shell), sendo assim sintetizado MIP magnético (MMIP) para valerato de estradiol, usando ácido metacrílico (MF) e TRIM (ME); aumentando o reconhecimento do MIP e, além de, facilitar a separação do material da solução pela aplicação de um campo magnético externo. Todos os materiais sintetizados foram amplamente caracterizados, física e físico-quimicamente. O material sintetizado apresentou um excelente magnetismo (2,0 emu g-1 ), uma alta porcentagem de retenção (superior a 80%) e um Qmáx acima de 24 mg g-1 , indicando que é promissor para adsorção de valerato de estradiol.
The development of selective and sensitive analytical methods has significant importance for an improvement at determination of chemical species; increasing the reliability of the results obtained. So, the use and optimization of separation and concentration steps is necessary. The use of Molecularly Imprinted Polymers (MIP) has been shown to be an efficient analytical tool with great potential to minimize the limitations of separation/concentration techniques traditionally employed. In the case of this study, the template used will be estradiol valerate, once of its inherent importance in female hormone replacement and because it is an endocrine disruptor (hormone) released into the environment without any control. Thus, the synthesis of the polymer for the identification of estradiol valerate was performed by different routes (bulk and precipitation) through two polymerization techniques (thermopolymerization and photopolymerization) by varying the functional monomer (MAA, acrylonitrile, 2-vinyl pyridine and 1- vinylimidazole). MIP and NIP were placed in a soxhlet system containing 70/30 methanol/acetic acid at 60 ° C for removal of the imprinted molecule through five successive washes in 24 h periods. These wash waters were analyzed using UV/Vis spectrophotometry. Subsequently, with the optimized parameters, the polymer that presented the best result was modified with magnetic nanoparticles (core@shell); being synthesized magnetic MIP (MMIP) for estradiol valerate, increasing the recognition of the MIP and, furthermore, facilitating the separation of the material from the solution by the application of an external magnetic field. It was used methacrylic acid as functional monomer, TRIM as structural monomer and all the synthesized materials were widely characterized, physically and physico-chemically. The synthesized material showed excellent magnetism (2.0 emu g-1 ), an elevate percentage retention (higher than 80%) and a Qmax above 24 mg g-1 , indicating that MMIP is a promising material for adsorption of estradiol valerate.
The development of selective and sensitive analytical methods has significant importance for an improvement at determination of chemical species; increasing the reliability of the results obtained. So, the use and optimization of separation and concentration steps is necessary. The use of Molecularly Imprinted Polymers (MIP) has been shown to be an efficient analytical tool with great potential to minimize the limitations of separation/concentration techniques traditionally employed. In the case of this study, the template used will be estradiol valerate, once of its inherent importance in female hormone replacement and because it is an endocrine disruptor (hormone) released into the environment without any control. Thus, the synthesis of the polymer for the identification of estradiol valerate was performed by different routes (bulk and precipitation) through two polymerization techniques (thermopolymerization and photopolymerization) by varying the functional monomer (MAA, acrylonitrile, 2-vinyl pyridine and 1- vinylimidazole). MIP and NIP were placed in a soxhlet system containing 70/30 methanol/acetic acid at 60 ° C for removal of the imprinted molecule through five successive washes in 24 h periods. These wash waters were analyzed using UV/Vis spectrophotometry. Subsequently, with the optimized parameters, the polymer that presented the best result was modified with magnetic nanoparticles (core@shell); being synthesized magnetic MIP (MMIP) for estradiol valerate, increasing the recognition of the MIP and, furthermore, facilitating the separation of the material from the solution by the application of an external magnetic field. It was used methacrylic acid as functional monomer, TRIM as structural monomer and all the synthesized materials were widely characterized, physically and physico-chemically. The synthesized material showed excellent magnetism (2.0 emu g-1 ), an elevate percentage retention (higher than 80%) and a Qmax above 24 mg g-1 , indicating that MMIP is a promising material for adsorption of estradiol valerate.
Descrição
Palavras-chave
Estrogênios, Polímeros impressos, Nanopartículas, Hormônios, Estrogens, Printed polymers, Nanoparticles, Hormones, Syntheses