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Développement d’une approche toxicocinétique/toxicodynamique basée sur des mécanismes physiologiques pour évaluer les effets oestrogéniques du Bisphénol A / Development of a physiologically-based toxicokinetic/toxicodynamic approach to assess the estrogenic effects of Bisphenol ACollet, Séverine 09 January 2012 (has links)
Ce travail a consisté à analyser, par des approches toxicocinétiques (TK) et mécanistiques, les effets oestrogéniques du Bisphenol A (BPA) sur un biomarqueur précoce et sensible : la sécrétion de l'hormone lutéinisante (LH) chez la brebis prépubère ovariectomisée. La plus faible concentration plasmatique en BPA induisant une inhibition de LH s'est avérée proche des concentrations maximales décrites chez l'Homme. Cette inhibition de LH pourrait impliquer une inhibition des systèmes neuronaux à kisspeptine. L'approche TK comparative d'espèces a montré que la clairance du BPA est toujours élevée, proche du débit sanguin hépatique. Pour une exposition à la dose journalière admissible, cette approche permet de prédire chez l'Homme des concentrations en BPA très inférieures à celles associées à une inhibition de LH dans notre modèle. / The goal of this thesis was to analyse through toxicokinetic (TK) and mechanistic approaches the estrogeno-mimetic effects of bisphenol A (BPA) on a precocious and sensitive biomarker: LH secretion in ovariectomized female lambs. The lowest plasma BPA concentrations associated to an inhibition of LH secretion appeared to be close to the highest one reported in human. LH suppression could be mediated by an inhibition of hypothalamic kisspeptin systems. The multispecies TK approach showed that BPA clearance is always high and equivalent to the liver blood flow. For an exposure scheme corresponding to the tolerable daily intake, this approach allows to predict human BPA concentration much lower than the one associated to LH inhibition in our highly sensitive lamb model.
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Optimalizace stanovení endokrinních disruptorů v čistírenských kalech a aplikace metody v reálných vzorcích. / Optimization of endocrine disruptors determination in wastewater treatment plant sludge and application of the method in environmental samples.Medková, Jaroslava January 2012 (has links)
Hormonaly active compounds in wastewaters represent nowdays a serious problem. Proceses currently used in watewater treatment plants (WWTP) are unefficient in removing these compounds from contaminated wastewaters. The compounds are supposed to sorb onto solid sludge elements and sediments. In this work seven endocrine disruptors were detected in the sludge samples from WWTPs. A new sensitive method for detection of seven selected endocrine disruptors (4-nonylphenol, bisphenol A, estriol, 17β-estradiol, estrone, 17α- ethynylestradiol, irgasan) was developed. The method is based on accelerated solvent extraction (ASE), gel permeation chromatography (GPC) and solid phased extraction. For final extract analysis, gas chromatography coupled with mass spectrometry (GC/MS) was used. The efficiency of this method was tested using artificially contaminated sludge and the method was used to analyse real samples from several WWTPs in Czech Republic. The effect of sludge age on detection of individual analytes was assessed as well. The concentrations of endocrine disruptors measured in the samples reached up to 1 µg/g. The results are comparable or higher then those reported in other works and they show the necessity of further research on endocrine disruptors in the environment.
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The use of cyclodextrin template-based metal oxide nanomaterials in the development of electrochemical sensors for phenolic endocrine disruptor compoundsMasikini, Milua January 2010 (has links)
<p>Iron oxide nanoparticles were prepared using co-precipitation method in the presence and absence of beta-cyclodextrin (&beta / -CD). Such materials were characterized using transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), attenuated total reflection Fourier transform infrared (ATR-FTIR), X-ray diffraction (XRD), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA). The TEM shows that the surface morphology has no difference between nanoparticles prepared in the presence and absence of beta-cyclodextrin (&beta / -CD), amorphous particles with high surface area and dimensions of about 100 nm by 500 nm. The amorphous states of nanoparticles are confirmed further by XRD. The ATR-FTIR analysis confirms inclusion complex between &beta / -CD and nanoparticles.</p>
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Development and application of a proteomic approach to the assessment of pollution in the marine environmentApraiz Larrucea, Itxaso January 2009 (has links)
Today, assessment of the health of coastal waters is recognized as being important for both the conservation of nature and well-being of humans. Anthropogenic pollution has been the focus of extensive research for some time and a variety of programs for the monitoring and assessment of environmental pollution have been developed. Determination of the levels of pollution in sensitive ‘sentinels’ such as mussels, allows monitoring of these levels in a given area over a prolonged period of time. Furthermore, the biological effects of pollution are reflected in a series of biomarkers, none of which provides a general picture of the sentinel’s state of health and all of which are individually specific for certain pollutants and influenced by both biotic and abiotic factors. In an attempt to improve biomonitoring of marine pollution, we have developed two proteomic approaches here. In the first portion of the thesis, a proteomic analysis was performed on peroxisomes isolated from mussels exposed either to one of three model anthropogenic pollutants, or two different types of crude oil, or from mussels exposed to the Prestige oil spill. Application of two-dimensional electrophoresis (2-DE) provided protein expression signatures (PES) for exposure to these different pollutants.Furthermore, several individual protein components of these PES could be putatively identified. In the second portion of this work, such analysis of subproteomes was developed further in order to improve the applicability of this approach to biomonitoring. A simple fractionation procedure in combination with liquid chromatography and 2-DE provided samples from mussels residing in different regions of a pollution gradient around the harbor of Gothenburg, as well as from mussels exposed to two types of fuel oil similar to that of the Prestige that were suitable for environmental proteomics. In addition, we constructed a model for this approach that can be cross-validated in the future and applied to assess sources of fuel oil pollution in connection with biomonitoring programs.
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The use of cyclodextrin template-based metal oxide nanomaterials in the development of electrochemical sensors for phenolic endocrine disruptor compoundsMasikini, Milua January 2010 (has links)
<p>Iron oxide nanoparticles were prepared using co-precipitation method in the presence and absence of beta-cyclodextrin (&beta / -CD). Such materials were characterized using transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), attenuated total reflection Fourier transform infrared (ATR-FTIR), X-ray diffraction (XRD), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA). The TEM shows that the surface morphology has no difference between nanoparticles prepared in the presence and absence of beta-cyclodextrin (&beta / -CD), amorphous particles with high surface area and dimensions of about 100 nm by 500 nm. The amorphous states of nanoparticles are confirmed further by XRD. The ATR-FTIR analysis confirms inclusion complex between &beta / -CD and nanoparticles.</p>
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The use of cyclodextrin template-based metal oxide nanomaterials in the development of electrochemical sensors for phenolic endocrine disruptor compoundsMasikini, Milua January 2010 (has links)
Magister Scientiae - MSc / Iron oxide nanoparticles were prepared using co-precipitation method in the presence and absence of beta-cyclodextrin β-CD). Such materials were characterized using transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), attenuated total reflection Fourier transform infrared (ATR-FTIR), X-ray diffraction (XRD), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA). The TEM shows that the surface morphology has no difference between nanoparticles prepared in the presence and absence of beta-cyclodextrin β-CD), amorphous particles with high surface area and dimensions of about 100 nm by 500 nm. The amorphous states of nanoparticles are confirmed further by XRD. The ATR-FTIR analysis confirms inclusion complex between β-CD and nanoparticles. The nanoparticles synthesized were used to develop an electrochemical sensor for phenolic endocrine disruptors by modifying the surface area of glassy carbon electrode (GCE). Electrochemical characterization of the iron oxide β-CD nano-composites, studied in 0.1 M potassium chloride (KCl) using chronoamperometry,showed that the surface concentration of the adsorbed composite material was 8.5 x 10-8 mol/cm2. Sensor analysis of bisphenol A (BPA) was carried out using cyclic voltammetry
(CV) and square wave voltammetry (SWV) based on amperometric techniques which gave a linear range of 0.50 × 10-6 M to 50 × 10-6 M; limit of detection of 0.156 x 10-6 M and order of magnitude of linearity of 2.03. Hence, the sensor was further used to study 4-tert-octylphenol (TOP); the results showed that the sensitivity and the limit of detection were 11.31 nA L/mol
and 0.249 x 10-6 M, respectively and order of magnitude of linearity of 2.00. / South Africa
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Desenvolvimento e validação de metodologia cromatográfica para determinação de bisfenol A em simulantes de alimentos de ensaios de migração / Development and validation of chromatographic method for the determination of bisphenol A in food simulants of migration tests.Linhares Junior, Gilberto Ferreira January 2012 (has links)
LINHARES JUNIOR, Gilberto Ferreira. Desenvolvimento e validação de metodologia cromatográfica para determinação de bisfenol A em simulantes de alimentos de ensaios de migração. 2012. 101 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Tecnologia de Alimentos, Fortaleza-CE, 2012 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-06-08T15:09:14Z
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Previous issue date: 2012 / This study aimed to develop and chromatographic method for the determination of bisphenol A in four different food simulants using high performance liquid chromatography and diode array detector (PDA) to support in enasios migration. The simulating used were A (purified water), B (solution aquosade 3% acetic acid), C (aqueous 10% ethanol) and D (aqueous 95% ethanol). Preliminary assessment of the analytical conditions was conducted in order to establish those that confer the best results, which were the system of mobile phase acetonitrile-water in the ratio 70:30 by volume, 40 ° C oven and length of the column wavelength of 201 nm. The retention time of the bisphenol A was found to be 3.25 minutes. For simulating the method of treatment consists of evaporation of sample 1 ml of sample at 60 ° C with duration of 1 hour and 45 minutes (A and C), 2 hours (B) and 1 hour (D). In sequence, the method was evaluated with respect to the parameters of analytical validation, including linearity, limit of detection and quantification, repeatability, intermediate precision between different analysts and between different days, recovery, selectivity and robustness. The method for simulating the coefficient for determining (r ²) or greater than 0.9988 in the range tested (50 to 2000 ppb); detection limit and quantitation, respectively, 14.7 ppb and 48.9 ppb; coefficient variation in repeatability of 2.07% for the inter-day precision of 1.05% and the accuracy of inter-Analyst 1.76%, recovery of 97.9% (CV = 1.3%) (50 ppb ), 99.2% (CV = 0.7%) (1000 ppb) and 103.6% (CV = 0.4%). The results for the simulant B includes coefficient of determination (r ²) 0.9972 or higher; limit of detection and quantification, respectively, 7.8 ppb and 26.0 ppb; coefficients of variation for repeatability of 3.74%, inter day precision, accuracy and 0.14% cross-Analyst 0.2%, 94.8% recovery (CV = 4.8%) (50 ppb) and 99.8% (CV = 0.2% ) (1000 ppb) and 92.3% (CV = 1.2%) (2000 ppb). For the simulant C results include a coefficient of determination (r ²) 0.9988 or higher; limit of detection and quantification, respectively, 4.8 ppb and 16.1 ppb, coefficient of variation for repeatability of 2.84%, accuracy inter-day precision of 1.37% and inter-analysts of 0.14%; de104 recovery, 6% (CV = 2.5%) (50 ppb), 99.8% (CV = 1.3%) ( 1000 ppb) to 102.5% (CV = 2.9%) (2000 ppb). The results for simulating D was 0.9984 r ² or more, detection limit and quantitation, respectively, 13.7 ppb and 45.6 ppb; coefficient of variation of 2.0% to repeatability, accuracy of an inter-day 9% and accurate inter-de1 analysts, 2%; recuperção 92.6% (CV = 1.76%) (50 ppb) and 99.9% (CV = 0.9%) (1000 ppb) and 104 8% (CV = 2.7%) (2000 ppb). There were no significant interferences to the method tested and proved to be robust. / Este trabalho teve como objetivo o desenvolvimento e metodologia cromatográfica para a determinação de bisfenol A em quatro diferentes simulantes de alimentos utilizando cromatografia líquida de alta eficiência e detector de arranjo de diodo (PDA) para suporte em enasios de migração. Os simulantes utilizados foram A (água purificada), B (solução aquosade ácido acético a 3%), C (solução aquosa de etanol a 10%) e D (solução aquosa de etanol a 95%). A avaliação preliminar das condições de análise foi conduzida com a finalidade de estabelecer aquelas que conferem os melhores resultados, os quais foram o sistema de fase móvel acetonitrila-água na proporção volumétrica 70:30, temperatura de 40°C do forno da coluna e comprimento de onda em 201 nm. O tempo de retenção do bisfenol A encontrado foi de 3,25 minutos. Para os simulantes, o método de tratamento consistiu da evaporação de 1 ml de amostra amostra a 60°C com duração de 1 hora e 45 minutos (A e C), 2 horas (B) e 1 hora (D). Em sequência, o método foi avaliado com relação aos parâmetros de validação analítica, incluindo linearidade, limite de detecção e de quantificação, repetibilidade, precisão intermediária entre analistas diferentes e entre dias diferentes, recuperação,seletividade e robustez. O método desenvolvido para o simulante A apresentou coeficiente de determinação (r²) 0,9988 ou superior no intervalo testado (50 a 2000 ppb); limite de detecção e de quantificação , respectivamente, 14,7 ppb e 48,9 ppb; coeficiente de variação para repetibilidade de 2,07%, para a precisão inter-dias de 1,05% e para a precisão inter-analistas de 1,76%; recuperação de 97,9% (CV= 1,3%) (50 ppb), 99,2% (CV= 0,7%) (1000 ppb) e 103,6% (CV= 0,4%). Os resultados obtidos para o simulante B incluem coeficiente de determinação (r²) 0,9972 ou superior; limite de detecção e de quantificação, respectivamente, 7,8 ppb e 26,0 ppb; coeficientes de variação para repetibilidade de 3,74%, precisão inter-dias de 0,14% e precisão inter-analistas de 0,2%; recuperação de 94,8% (CV= 4,8%) (50 ppb), 99,8% (CV= 0,2%) (1000 ppb) e 92,3% (CV= 1,2%) (2000 ppb). Para o simulante C os resultados incluem coeficiente de determinação (r²) 0,9988 ou superior; limite de detecção e de quantificação, respectivamente, 4,8 ppb e 16,1 ppb; coeficiente de variação para repetibilidade de 2,84%, precisão inter-dias de 1,37%e precisão inter-analistas de 0,14%; recuperação de104,6% (CV= 2,5%) (50 ppb), 99,8% (CV= 1,3%) (1000 ppb) e 102,5% (CV= 2,9%) (2000 ppb). Os resultados para o simulante D foram r² 0,9984 ou superior; limite de detecção e de quantificação,respectivamente, 13,7 ppb e 45,6 ppb; coeficiente de variação para repetibilidade de 2,0%, precisão inter-dias de 1,9% e precisão inter-analistas de1,2%; recuperção de 92,6% (CV= 1,76%) (50 ppb), 99,9% (CV= 0,9%) (1000 ppb) e 104,8% (CV= 2,7%) (2000 ppb). Não foram observados interferentes importantes para o método testado, mostrando-se robusto.
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Efekt xenobiotik na DNA integritu a fyziologii rybích spermiíLINHARTOVÁ, Pavla January 2013 (has links)
Pollution of the aquatic environment with xenobiotics has become a serious health concern in recent years. In the present study the effect of DQ, TBBPA, BPA and VIN on sperm quality parameters, DNA integrity and oxidative stress indices in sterlet (Acipenser ruthenus) sperm and sperm from brook trout (Salvenilus fontinalis) were investigated. To do this, an in vitro spermatozoa motility assay was used by a computer-aided Motion-Analysis system. The sperm of sterlet (Acipenser ruthenus) was diluted to obtain the spermatozoa density of 5×108 cells×ml?1 and then exposed for 2 h to final concentrations of xenobiotics: DQ - 25, 50, 100 and 150 ?M, TBBPA - 0.5, 1.75, 2.5, 5, 7.5 and 10 ?g/l, BPA - 0.5, 1.75, 2.5, 5 and 10 ?g/l and Vin - 0.5, 1.75, 2.5, 5 and 10 ?g/l. Spermatozoa velocity and percentage of motile sperm were significantly decreased at each time post-activation compare to control. The level of DNA damage expressed as a % DNA in Tail and Olive Tail moment significantly increased when spermatozoa were exposed to higher concentrations of xenobiotics. The level of oxidative stress indices lipid peroxidation (LPO) and carbonyl derivatives of proteins (CP) and antioxidant activity of superoxide dismutase (SOD) increased significantly with increasing concentration of xenobiotics. On the other hand the intracellular ATP content in sperm samples had a significantly decreasing effect. In short, xenobiotics can induce reactive oxygen species (ROS) stress in fish spermatozoa, which could impair the sperm DNA integrity, quality and antioxidant defense system. The present study confirms that environmental concentrations of xenobiotics are capable to induce oxidative stress, leading to impaired sperm quality, DNA fragmentation and intracellular ATP content Obtained results also suggested that the use of fish spermatozoa in vitro assays may provide a novel and efficiently means for monitoring residual pharmaceutical in aquatic environment.
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Bisfenol A : validação de método e ocorrência em água superficial e tratada da cidade de Araraquara /Leandro, Fernanda Zampieri. January 2006 (has links)
Orientador: Mary Rosa Rodrigues de Marchi / Banca: Manoel Lima de Menezes / Banca: Eny Maria Vieira / Resumo: Atualmente há um grande interesse no estudo dos desreguladores endócrinos (substâncias estranhas aos organismos, que mimetizam ou bloqueiam a ação natural dos hormônios naturais), tanto em relação ao seu destino ambiental quanto à toxicologia dos mesmos. Neste trabalho, avaliou-se o Bisfenol A (BPA), um monômero do qual se produz o plástico policarbonato. Recentemente foi proposto que o BPA exibe atividade estrogênica em concentrações de 1 ng mL-1. Neste trabalho, desenvolveu-se um método para a determinação de BPA em águas naturais, fazendo-se uso de cartuchos de poliestireno-divinilbenzeno (PSDVB) para a extração em fase sólida (SPE) e cromatografia líquida de alta eficiência com um detector de fluorescência (HPLC/FLU) para a quantificação do composto. A recuperação do método foi avaliada utilizando-se amostras de água potável fortificada em 3 níveis de concentração: 0,06; 0,2 e 0,6 ng mL-1. A extração do analito (500 mL; n=4) resultou valores de recuperações entre 99 e 100% e CV entre 0,30 e 3,9%. Os limites de detecção e quantificação do método foram 0,02 e 0,06 ng mL-1, respectivamente. O mesmo estudo foi efetuado para água superficial sendo obtidos valores de recuperação entre 85,8 e 87% para níveis de fortificação similares aos utilizados para água potável, com CV entre 1,1 e 2,3%. O método validado foi aplicado com bom desempenho às amostras de água de entrada e saída da Estação de Tratamento de Água, onde constatou-se a presença de BPA entre 11,7 e 16,8 ng mL-1 na água bruta e 6,2 e 7,3 ng mL-1 na água potável. Desta forma, o monitoramento ambiental do BPA torna-se extremamente relevante e necessário. / Abstract: Nowadays it has been increased the concern about endocrine disrupters (unknown substances for organisms that mimic or block the natural action of endogenous hormones), so much at relation of your environmental fate as toxicology about them. In this study, it had been evaluated Bisphenol A (BPA), a monomer, wich produces polycarbonate. Recently, it has been proposed that BPA exhibits estrogenic activity at 1 ng mL-1. At this work, it had been developed a method for determination of BPA at natural water with polistyrene-divinylbenzene (PSDVB) cartridge on phase solid extraction (SPE) and high performance chromatography liquid with fluorescence detection (HPLC/FLU) for the analyte's quantification. The method's recovery was evaluated with spiked drink water sample at three concentrations levels: 0,06; 0,2 and 0,6 ng mL-1. The analyte extraction (500 mL; n=4) gave recoveries between 99 and 100% with CV between 0,30 and 3,9%. The method detection and quantification limits were 0,02 and 0,06 ng mL-1, respectively. The same study was developed for superficial water with recoveries between 85,8% and 87% for similar spiked levels at the drink water with CV between 1,1 and 2,3%. The method developed was applied with good performance at water's samples of Water Treatment Plant, verifying the appearance of BPA between 11,7 and 16,8 ng mL-1 on sewage water and 6,2 until 7,3 ng mL-1 on drink water. Therefore the environmental monitoring of BPA is very important and indispensable. / Mestre
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Construção, caracterização e aplicação analítica de microdispositivos enzimáticosCerqueira, Marcos Rodrigues Facchini 09 September 2016 (has links)
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Previous issue date: 2016-09-09 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O foco deste trabalho foi o desenvolvimento e aplicação de microreatores enzimáticos, visando sua aplicação em sistemas de análise por injeção em fluxo. Em cima disso, dois substratos poliméricos foram utilizados para a avaliação de imobilização enzimática: um à base de poli (metil metacrilato) (PMMA) e outro em uma resina do éter diglicídico do bisfenol-A (BADGE). Uma impressora à laser de CO2 foi utilizada para confeccionar os dispositivos nas dimensões desejadas. Para o sucesso da imobilização, os sistemas foram previamente tratados com polietilenoimina (PEI) visando a introdução de grupamentos funcionais reativos na superfície dos materiais de partida. Num primeiro estudo, baseado na modificação de PMMA, a ativação do material foi conseguida após tratamento dos microcanais com PEI em meio de dimetilsulfóxido (DMSO). Já no segundo caso o tratamento com PEI envolveu a simples mistura mecânica dos materiais, objetivando a cura da resina empregada. Após a ativação dos materiais com PEI, as enzimas foram imobilizadas após passagem de uma mistura de glutaraldeído (um agente espaçador) e as enzimas. Dentre as enzimas estudadas estão a glicose oxidase (GOx), a ascorbato-oxidase (AAO), a catalase (CAT), a glutamato dehidrogenase (GDH), além de um sistema híbrido baseado na imobilização simultânea das enzimas glicose oxidase (GOx) e horseradish peroxidase (HPR). A caracterização dos sistemas desenvolvidos foi feita primordialmente por meio da espectroscopia Raman. Além disso, a aplicação de alguns dos sistemas frente a amostras reais e o cálculo de parâmetros cinéticos e operacionais dos microreatores confeccionados foram reralizados. Essas avaliações foram feitas baseadas em sistemas de detecção desenvolvidos no laboratório por técnicas eletroquímicas e por espectroscopia no visível. Como grande benefício dos sistemas desenvolvidos, podem ser destacados a velocidade e a simplicidade de implementação do processo de imobilização e operação. / The focus of this work is the development and application of enzymatic microreactors aiming their application through flow injection analysis systems. On top of that, two polymeric substrates were used for the evaluation of enzyme immobilization: one based on poly (methyl methacrylate) (PMMA) and another baed on a bisphenol-A diglycidyl ether resin (BADGE). A CO2 laser printer was used to fabricate the devices at the desired dimensions. For the success of the immobilization systems have been pretreated with polyethyleneimine (PEI) in order to introduce reactive functional groups on the surface of the starting materials. In a first study, based on PMMA modification, the activation of the material was achieved after treating microchannels with PEI in dimethylsulfoxide (DMSO). In the second case, treatment with PEI involved simply a mechanical mixture of the two materials, in order to cure the resin. After activation of materials with PEI, the enzymes were immobilized after passage of a mixture of glutaraldehyde (a spacer agent) and enzymes. Among the enzymes studied are glucose oxidase (GOx), ascorbate oxidase (AAO), catalase (CAT), dehydrogenase glutamate (GDH), and a hybrid system based on the simultaneous immobilization of the enzymes glucose oxidase (GOx) and horseradish peroxidase (HPR). The characterization of the developed systems was primarily done by Raman spectroscopy. Moreover, application of some of the proposed systems to real samples and calculation of kinetic and operational parameters are presented during the study. These evaluations were made with detection systems based on electrochemical and visible spectroscopy techniques, all developed at the laboratory. One great benefit of the developed systems, are the speed and simplicity of implementation the immobilization process and operation of the devices.
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