Formação, estabilidade coloidal e atividade in vitro contra Candida albicans dos arranjos supramoleculares compostos por drogas, lípides catiônicos e/ ou polieletrólitos foram sistematicamente avaliados através de espalhamento de luz dinâmico para tamanho de partículas, análise de potencial-zeta, espectrofotometria UV-visível, efeitos de droga sobre a transição de fase gel para líquido-cristalina da bicamada catiônica e quantificação de incorporação de droga nos diferentes sistemas. Arranjos supramoleculares de drogas antifúngicas como miconazol ou anfotericina B foram obtidos por solubilização das drogas em fragmentos de bicamada catiônica de brometo de dioctadecildimetilamônio ou como partículas de droga recobertas com uma camada do mesmo lípide catiônico. Como modelo de droga anticancerígena, a cisplatina foi incorporada com sucesso em polieletrólitos de carga oposta: quitosana e carboximetilcelulose. Cisplatina induziu substancial estabilização coloidal e redução de tamanho de partículas de carboximetilcelulose-quitosana, possivelmente atuando como agente de ligação cruzada entre os dois polieletrólitos. Assim também, arranjos supramoleculares de anfotericina B em baixa e em alta proporção molar droga: lípide catiônico foram revestidos com polieletrólitos como carboximetilcelulose, cloreto de poli(dimetildialilamônio) e polilisina formando nanopartículas catiônicas. Nanopartículas catiônicas de anfotericina B apresentaram estabilidade coloidal e atividade fungicida ótima. Quanto aos arranjos do miconazol com os fragmentos de bicamada catiônica, observou-se o mesmo com a vantagem de se obter ação sinérgica entre o lípide catiônico e a droga. Dois sítios de interação com fragmentos de bicamada catiônica foram identificados para o miconazol: (1) as bordas hidrofóbicas disponíveis à temperatura ambiente; (2) os sítios no seio da bicamada ocupados com o aumento de temperatura. A potente ação antimicrobiana do lípide catiônico brometo de dioctadecildimetilamônio (DODAB) per se, motivou um estudo sistemático da ação antimicrobiana comparada de DODAB e brometo de cetiltrimetilamônio (CTAB) contra Candida albicans. A adsorção destes compostos e seus agregados sobre a célula diminuiu seguindo a ordem: CTAB > fragmentos de bicamada de DODAB > vesículas grandes de DODAB. A ausência de vazamento de compostos fosforilados intracelulares de baixo peso molecular, DNA ou proteína em presença dos catiônicos evidenciou mecanismo de ação antimicrobiana independente de lise celular. A adsorção dos compostos catiônicos sobre células de Candida albicans mudou o sinal de potencial da superfície celular de negativo para positivo, exibindo uma relação clara entre a carga positiva sobre a célula e morte celular. / The formation, colloid stability and activity in vitro against Candida albicans of several supramolecular assemblies composed of drug, cationic lipid and/or polyelectrolytes were systematically evaluated by means of dynamic light scattering for particle sizing, zeta- potential analysis, UV-visible spectroscopy, effect of drug on gel-to-liquid-crystalline phase transition of the cationic bilayer and determination of drug loading. Supramolecular assemblies of antifungal drugs such as miconazole and amphotericin B were obtained by solubilization of the drugs in cationic bilayer fragments composed of dioctadecyldimethylammonium bromide or coverage of drug particles with a layer of the quoted cationic lipid. As a model of anticancer drug, cisplatin was sandwiched between two oppositely charged polyelectrolytes: chitosan and carboxymethylcellulose. Cisplatin induced reduction in particle size acting as a cross-linker between polyelectrolytes. For amphotericin B, at low and high molar proportion drug to cationic lipid, similar supramolecular assemblies were coated by polyelectrolytes such as carboxymethylcellulose, poly(diallyldimethylammonium) and polylysine yielding cationic nanoparticles that presented optimal colloid stability and fungicidal activity. Miconazole became attached at the hydrophobic edges of bilayer fragments at room temperature and/or, upon an increase in temperature, inserted in the bilayer core. Curiously, this last formulation in the cationic lipid yielded a synergistic action against Candida albicans. Dioctadecyldimethylammonium bromide (DODAB) is an excellent antimicrobial agents per se. Its mechanism of antimicrobial action was compared to the one for hexadecyltrimethylammonium bromide (CTAB). Adsorption of these compounds on the cells decreased going from CTAB to DODAB bilayer fragments and to large vesicles. Absence of leakage of small phosphorylated compounds, proteins or DNA from fungus indicated a mechanism of action different from cell lysis. Adsorption of the cationic compounds changed the sign of the cell zeta-potential from negative to positive. There was a clear relationship between positive charge on fungus and death.

Lipossomos são vesículas microscópicas compostas de uma ou mais membranas lipídicas envolvendo um compartimento aquoso, e podem ser constituídos de moléculas naturais ou sintéticas, como o brometo de dioctadecildimetilamônio (DODAB), um composto de amônia quaternário. Este trabalho mostra: 1) susceptibilidade de quatro espécies bacterianas à ação bactericida de DODAB; 2) verificação da ação antifúngica de DODAB; 3) solubilização de duas drogas antifúngicas (anfotericina B e miconazol) nos lipossomos de DODAB; 4) verificação da eficiência das drogas incorporadas aos lipossomos, como agentes antifúngicos. A susceptibilidade das espécies ao DODAB foi avaliada através de curvas de viabilidade celular para 2,5 x 107 UFC/mL. A bactéria mais resistente foi Escherichia coli, seguida de S. Typhimurium, P. aeruginosa, e S. aureus. Foi demonstrada uma correlação entre a troca de carga de superfície das bactérias e a morte celular. A ação antifúngica do DODAB foi avaliada para Candida albicans através de curvas de viabilidade celular. DODAB é fungistático (1 mM), e bactericida (10-50 µM). Formulações lipossomais de DODAB com anfotericina B ou miconazol mostraram ação fungicida equivalente àquela das drogas sozinhas, em seus melhores solventes. A fase lipossomal de DODAB compete com a membrana da célula fúngica pela anfotericina B, conforme verificado pelo efeito de concentração de DODAB. A 1 mM de DODAB, a fase lipossomal ganha a competição na solubilização da droga para as membranas das células fúngicas e a droga não é entregue para as células. Contudo, a 0,1 mM de DODAB, as membranas ganham a competição e a droga é entregue. / Liposomes are microscopic vesicles composed by one or more lipid membranes surrounding an aqueous compartment. Some synthetic amphiphilic molecules, such as dioctadecyldimethylammonium bromide (DODAB), a quaternary ammonium compound also assemble as vesicles. This work is divided in four parts: 1) susceptibility of four bacterial species to the bactericidal DODAB action; 2) characterization of DODAB\'s antifungal action; 3) solubilization of two hydrophobic antifungal drugs (amphotericin B and miconazole) in DODAB liposomes; 4) determination of efficiency for the liposomal drugs. The susceptibility of four species of bacteria was determined from cell viability in the presence of DODAB at 2.5 x 107 CFU/mL. The less susceptible specie is Escherichia coli, followed by S. Typhimurium, P. aeruginosa and S. aureus. There is a relationship between cell surface charge and viability. Negatively charged cells remain alive whereas positively charged cells die. The antifungal action of DODAB towards Candida albicans was evaluated from the determination of cell viability as a function of DODAB concentration. DODAB is fungistatic at 1 mM concentration, and bactericidal at tenths of micromolar (10-50 µM). Liposomal amphotericin B or miconazole present fungicidal action similar to that of the drugs when solubilized in their best solvents. DODAB at 1 mM competes with the fungal cell membrane for amphotericin B solubilization. At 1 mM of DODAB, the liposomal phase wins the competition for drug solubilization and the drug is not delivered to the cell. However, at 0.1 mM of DODAB, the cell membrane wins and the drug is delivered.

Neste estudo, testamos a hipótese de que a estimulação colnérgica pela administração de piridostigmina, um agente anticolinesterásico reversível, protege o miocárdio submetido à isquemia miocárdica crônica durante 3 tempos de observação: 7, 21 e 42 dias. Para essa avaliação foram medidos a área de acinesia (índicador de área de infarto), os índíces das funções sistólica e diastólica pela ecocardiografia e por medida direta bem como marcadores da função autonômica como a sensibilidade do barorreflexo e a variabilidade da frequência cardíaca (FC) e da pressão arterial (PA). O bloqueio farmacológico do sistema nervoso autônomo e o estudo da via eferente parassimpática foram também realizados. Utilizou-se ratos Wistar machos divididos em 4 grupos: controle, controle piridostigmina, infartado e infartado piridostigmina. Os resultados mostraram os efeitos protetores da piridostigmina nos diferentes tempo de infarto com redução da área de acinesia ( maior que 80%) tanto pelo ecocardiograma quanto pela histologia. Além disso observou-se recuperação das funções sistólica e diastólica, com normalização da pressão diastólica final e das derivadas de contração e relaxamento. Essas melhoras foram mais consistentes em 21 e 42 dias, sem diferenças entre esses tempos de tratamento. Em 7 dias ainda persistiram alguns índices de disfunção ventricular, embora a função autonômica estivesse bem preservada. Parte dessa melhora se deve, provavelmente, ao aumento do tônus vagal e redução do simpático. A potenciação da bradicardia pela estimulação elétrica do vago induzida pela piridostigmina confirma seu papel com estimulador colinérgico. A sensibilidade do barorreflexo reduzida de forma semelhante pelo infarto do miocárdio aos 7, 21 e 42 dias, voltou aos valores controle após o tratamento com piridostigmina, sem diferenças devidas ao tempo de tratamento. Da mesma forma, a variabilidade da FC foi aumentada após o tratamento com o brometo de piridostigmina no grupo infartado o que também ocorreu no grupo controle. Em adição, o aumento da banda de alta frequência e a redução da banda de baixa frequência que refletem respectivamente a modulação parassimpática e simpática da variabilidade da frequência cardíaca, levaram a uma redução no balanço simpato-vagal dos animais infartados tratados. Em conclusão, a estimulação colinérgica por piridostigmina preserva a função parassimpática protegendo o miocárdio da isquemia induzida por oclusão coronariana, mantendo a função cardíaca e a função autonômica dentro dos valores da normalidade / In this study we tested the hypothesis that cholinergic stimulation by pyridostigmine administration, a reversible cholinergic inhibitor, protects the ischemic myocardial in three periods of follow-up: 7, 21 and 42 days. For this evaluation we measured the akinetic area (infacrtion area indicator), systolic and diastolic indexes by echocardiography and left ventricle direct measurements as well as autonomic function markers, as baroreflex sensitivity and heart rate (HR) and blood pressure (BP) variabilities. Pharmacological blockade of the autonomic nervous system and the study of the efferent parasympathetic pathway were also performed. Male Wistar rats were divided in 4 groups: control, control treated with pyridostigmine, infarcted and infarcted treated with pyridostigmine. The results showed the protective effects of pyridostigmine in the different periods of infarction, with the reduction of the akinetic area (more than 80%), either by the echocardiography and by histology. Moreover, we observed systolic and diastolic functions recovery, with normalization of the end diastolic pressure and the maximum rates of left ventricle BP rise and fall. These improvements were more consistent in 21 and 42 days, with no differences between these two periods of treatment. In 7-day treatment, some indexes of ventricular dysfunction remained, although the autonomic function seemed to be preserved. Part of these improvements is probably due to the increase in the vagal tonus and the decrease in the sympathetic tonus. The pyridostigmine effects in the potencialization of the bradycardia induced by vagus nerve electrical stimulation confirms its role as a cholinergic stimulator. The reduced baroreflex sensitivity by myocardial infarction, which was similar in 7, 21 and 42 days, returned to control values after pyridostigmine treatment, without differences related to treatment extent. Similarly, HR variability was increased after pyridostigmine treatment in the infarcted group, which also occurred in the control group. In addition, the increase in the high frequency band and the reduction in the low frequency band, which reflect, respectively, the parasympathetic and the sympathetic modulation of HR variability, led to the diminishment in the sympatho-vagal balance in the infarcted-treated animals. In conclusion, cholinergic stimulation by pyridostigmine preserves parasympathetic function, protecting the myocardial against the ischemia induced by coronary occlusion, maintaning cardiac and autonomic functions within normal values

Adsorption on solid surfaces from solution is a fundamental property of a surfactant. It might even be the most important aspect of surfactant behavior, since it influences many applications, such as cleaning, detergency, dispersion, separation, flotation, and lubrication. Consequently, fundamental investigations of surfactant adsorption are relevant to many areas. The main aim of this thesis has been to elucidate the adsorption properties, primarily on the solid/water interface, of a particular class of polyhydroxyl based surfactants: the alkyl glucosides. By the use of ellipsometry, the equilibrium and kinetic aspects of adsorption on titanium dioxide with respect to structural effects has been studied. Furthermore, the effects of small amounts of cationic surfactant additives on the adsorption on silica have been investigated. The results have been compared with similar studies for other nonionic surfactants. We have found that the surfactant structure has a strong effect on the adsorption properties. An increase in the surfactant chain length increases the cooperativity of the system. An increase in the head group polymerization decreases the cooperativity and the plateau adsorbed amount at equilibrium. The effect of surfactant structure on the adsorption kinetics depends on the concentration relative to the cmc, while the there is a decrease in the rate of desorption with increasing hydrophobic chain length independent of the concentration. The adsorption/desorption process is concluded to be diffusion driven, as suggested by the model used. When comparing these results with studies on ethylene oxide based surfactants, we conclude that the two types of surfactants exhibit similar trends on surfaces onto which they adsorb. Adsorption from binary surfactant solutions is even more interesting than adsorption from single surfactant solutions, since it brings us one step closer to the systems used in applications. In addition, adsorption from a mixture can be very different from adsorption from any of the single surfactants in the mixture. Alkyl glucosides alone do not adsorb on silica, but addition of small amounts of a cationic surfactant to the alkyl glucoside solution allows for adsorption on silica. A comparison between the adsorption and bulk properties has shown that mixed micellization explains most, but not all, effects of the coadsorption properties. Changing the pH in the mixed systems reveals that a surfactant with a pH-dependent charge and the ability to adapt its charge to the environment, e.g. a surface, enhances the adsorbed amount over a wider range of pH values than a purely cationic surfactant. It is well known that alkyl glucosides and ethylene oxides adsorb differently on different types of hydrophilic surfaces. As a consequence, replacing ethylene oxides with alkyl glucosides might not be all straight-forward; however, we have shown that the effect of the surface can be eliminated by the use of a cosurfactant. / <p>QC 20101018</p>

With increasing environmental awareness and natural resource limitations, researchers must begin to incorporate sustainability into their process and product designs. One target for green engineering is in reaction and separation design. This is typically done in a wasteful and often toxic manner with organic solvents and lack of recycle. The following thesis discusses alternatives to these costly separations by means of ionic liquids, benign extraction, separation with carbon dioxide, and near critical water. Ionic liquids are combined with carbon dioxide to induce melting point depressions of up to 124 degrees Celsius. Using this system as a reaction medium will offer control over the reaction phases while utilizing green solvents. Benign extractions are performed on both ferulic acid and on proteins from biomass by replacing alkaline solvents and costly protein separation techniques with simple liquid-liquid extraction. This means simpler systems and less waste than from previous methods. This thesis also discusses an opportunity for more efficient separation and recycle of a pharmaceutical catalyst, Mn-Salen. Using carbon dioxide with the organic aqueous tunable solvent system, the reaction can be run homogeneously and the product and catalyst separated heterogeneously, thus creating an extremely efficient process. Lastly, near critical water is used as an extraction and reaction medium by extracting ferulic acid from Brewers Spent Grain and then catalyzing its transformation to 4-vinylguaiacol. In this manner a simple, benign process is used to turn waste into valuable chemicals. Although somewhat different, each of the studied processes strives to eliminate waste and toxicity of many commonly used reaction and separation techniques, thus creating safe and sustainable processes.

Hydrogen is currently considered by many as the “fuel of the future”. It is particularly favoured as a replacement for fossil fuels due to its clean-burning properties; the waste product of combustion being water. While hydrogen is relatively easy to produce, there is currently a lack of practical storage methods for molecular H2, and this is greatly hindering the use of hydrogen as a fuel. Gases are normally stored in vessels under only moderate pressures and in liquid form where possible, which yields the highest energy density. However, to store reasonable quantities of hydrogen in similar volume containers, cryogenic temperatures or extreme pressure are required. Many potential hydrogen storage technologies are currently under investigation, including adsorption on metal hydrides, nanotubes and glass microspheres, and the chemical breakdown of compounds containing hydrogen to release H2. Recent studies have sparked interest in hydrates as a potential hydrogen storage material. The molecular storage of hydrogen in clathrate hydrates could offer significant benefits with regard to ease of formation/regeneration, cost and safety, as compared to other storage materials currently under investigation. Here, we present new experimental hydrate stability data for sII forming hydrogen–water (up to pressures of 180 MPa) and hydrogen–water–tetrahydrofuran systems, the structure-H forming hydrogen–water–methyclycohexane system, and semi-clathrate forming hydrogen–water–tetra-n-butyl ammonium bromide/tetra–n-butyl ammonium fluoride systems.

19 Dec 2004. / Published through the Information Bridge: DOE Scientific and Technical Information. "IS-T 2009" Ivana Adamovic. 12/19/2004. Report is also available in paper and microfiche from NTIS.

Le stockage de l'énergie solaire thermique s'avère aujourd'hui nécessaire si on veut atteindre une meilleure efficacité et une utilisation à grande échelle de cette ressource. Le stockage sous forme de potentiel chimique se révèle être adapté au stockage de chaleur sur le long terme (cycles saisonniers ou pluriannuels) parce qu'il présente les moindres pertes thermiques par rapport au stockage sensible ou latent. Malgré les avancées significatives faites ces dernières années dans ce domaine, il n'existe pas aujourd'hui de système achevé dédié à ce type de stockage. Le but du présent travail est de démontrer la faisabilité d'un procédé de stockage de chaleur solaire à long terme par absorption pour le chauffage des bâtiments. La chaleur est stockée en été grâce à la désorption et restituée en hiver à travers l'absorption. Une analyse multicritère portant des couples de sorption possibles a permis d'identifier le couple LiBr−H2O pour la démonstration de faisabilité du concept. Il a été montré que la cristallisation d'une partie de la solution permet de multiplier par trois la densité de stockage énergétique et donc d'améliorer la compétitivité du procédé. Un modèle dynamique a été développé pour dimensionner et simuler les performances du système sous différentes conditions opératoires. De nombreuses simulations paramétriques ont permis de discuter de l'influence de différents paramètres et aspects du contrôle du procédé. Cela a donné lieu à la conception et au dimensionnement d'un prototype de démonstration capable de stocker 8 kWh de chaleur et de produire une puissance moyenne de chauffage de 1 kW. Ce prototype a été construit et expérimenté en fonctionnement statique et dynamique sur un banc d'essai, dans des conditions compatibles avec une installation solaire domestique. La faisabilité de la charge du procédé a ainsi été démontrée. L'absorption durant la phase de décharge est effective bien que des problèmes, dus notamment à une conception inadaptée de l'absorbeur, n'ont pas permis d'assurer la restitution de la chaleur. Différents aspects tels que la stratification et la circulation de la solution dans son réservoir ont également été abordés. La confrontation du modèle et des résultats expérimentaux a ainsi été réalisée et discutée. / Energy storage is a key component to improve the efficiency of energy systems, especially when the energy source is intermittent, such as solar energy. Heat storage systems based on sorption processes are relevant in case of long-term storage (seasonal or pluriannual storage) because of their acceptable heat losses. Even though considerable breakthroughs have been made in the past decades, there is no mature long-term sorption heat storage yet. The aim of this work is to demonstrate the feasibility of a long term solar thermal storage by absorption for building space heating. Solar heat is stored in summer using desorption process and released in winter via absorption. A multicriteria analysis on various possible absorption couples leads to the choice of LiBr−H2O as storage media for the concept feasibility demonstration. It has been shown that crystallisation in the solution storage tank can increase the storage density by three times and therefore, is relevant for the process competiveness. A dynamic model has been developed for the system design and simulations under various operating conditions were performed. A lot of parametric simulations are used to investigate the influence of certain parameters and controls aspects. This helps designing a demonstrative prototype that can store 8 kWh of heat and can produce a heating power of 1 kW. The prototype has been built and tested on a test bed in static and dynamic operating conditions that are compatible with domestic solar thermal plants. The charging process has been proved successful. Absorption during discharging phase is also verified. However, some problems related to the absorber design have not made possible to observe the heat release as expected. Various aspects such as stratification and circulation in the solution storage tank have also been addressed. The model comparison with experimental result is then performed and discussed.

Brain stem remyelination following demyelination induced by ethidium bromide (EB) is carried out by oligodendrocytes and Schwann cells that invade the central nervous system when astrocytes are lost. Although oligodendrocyte remyelination is detected from 13 days onward within the lesions, the origin of the remyelinating cells is not known. To clarify oligodendrocyte origin as well as to observe astrocytic behaviour in normal (n=22) as well as immunosuppressed animals (n=22) adult Wistar rats were injected with EB in the basal cisterna. Wistar rats had an EB injection while treated with cyclophosphamide (astrocyte investigation, n=12) or cyclosporine A (oligodendrocyte study, n=10). Control animals had a single injection of 10 μl of 0.9% saline (n=16). For the investigation on astrocytes, the rats were killed at 1, 2, 3, 7, 14 and 21 days a.i. GFAP labelled astrocytes were conspicuous within the lesions and isomorphic gliosis was detected, more marked in those rats immunosuppressed with CY. Nonetheless a significant difference among the groups could not be established because of the mean deviations detected by the image studies. For the oligodendrocyte investigation the rats were killed at 15, 21 and 31 days a.i. Lesions of EB injected in normal and cyclosporine A-treated Wistar rats labelled positive for OSP (oligodendrocytes specific protein). This result points to mature oligodendrocytes as a source of remyelinating cells to restore the lost myelin sheaths after EB injection. The EB model of demyelination allowed the observation of the neuroglia in lesions where remyelination is made up by mature cells of the oligodendroglial lineage and where astrocytes respond selectively to immunosuppressive drugs that modify the inflammatory reaction induced by EB / Remielinização após desmielinização com brometo de etídio (BE) no tronco encefálico de ratos é realizada por oligodendrócitos e células de Schwann que invadem o tecido após a morte dos astrócitos. Embora a remielinização por oligodendrócitos seja detectada a partir dos 13 dias pós-intoxicação, a origem das células remielinizantes não é conhecida. Para esclarecer essa origem bem como o comportamento astrocitário em lesões induzidas pelo BE em ratos adultos normais (n=22) ou sob terapia imunomoduladora (n=22), ratos Wistar adultos receberam uma injeção de 10 μl de BE na cisterna basal. Ratos Wistar receberam a injeção de BE enquanto sob terapia imunossupressora com ciclofosfamida (estudo astrocitário) (n=12) ou ciclosporina-A (n=10) (estudo da oligodendróglia). Os animais controle receberam uma injeção de 10 μl 0.9% de solução salina (n=16). Para o estudo astrocitário, os animais foram sacrificados aos 1, 2, 3, 7, 14 e 21 dias pós-injeção de BE. Astrócitos foram marcados com GFAP (proteína glial fibrilar ácida) e foi detectada gliose isomórfica nas lesões, mais marcada naqueles animais tratados com ciclofosfamida (CY). Embora existisse diferença entre a marcação por GFAP nos ratos que receberam somente BE e os que receberam BE e CY, os desvios das médias obtidas através da análise de imagem, não permitiram uma conclusão sobre a significância dessa diferença. Os ratos do experimento sobre a oligodendróglia foram sacrificados aos 15, 21 e 31 dias p.i. do BE. Tecidos de ratos normais injetados com BE e ratos injetados e tratados com ciclosporina foram marcados com imunofluorescência (IF) para OSP (proteína específica do oligodendrócito) que marca células maduras da linhagem oligodendroglial. O resultado foi a marcação de células maduras que remielinizavam em áreas próximas ao tecido normal, mostrando oligodendrócitos maduros como fonte celular na reparação das bainhas perdidas. O modelo de desmielinização do BE permitiu estudar a atividade da neuróglia em lesões que foram remielinizadas por oligodendrócitos maduros e nas que os astrócitos responderam seletivamente a imunossupressores que interferem com a reação inflamatória dentro do tecido

The Epstein Barr virus (EBV) is studied in this project to establish a latency compared with the infected organism and to a number of pathophysiologies. Its oncogenic potential associated with serological evidence of the presence of the viral agent for cancer and also for autoimmune diseases such as rheumatoid arthritis and lupus erythematosus. Detection processes are necessary and have attracted scientific interest in recent decades, and they are important analytical tools used for clinical diagnosis, disease control, physiological changes, among others. Through the above two genosensors were developed to the specific recognition of EBV by electrochemistry. The peak oxidation of ethidium bromide (EB) in graphite electrodes modified with poly (4-ATP) and the peak tetramethylbenzindine (TMB) reduction, as a new indicator of hybridization oligonucleides, in graphite electrodes modified with poly (AP-4) were designed and evaluated these platforms. Analysis of Surface Plasmon Resonance (SPR) and Atomic Force Microscopy (AFM) were used to complement the study to theoretical and practical application. The prospect of this project is the application in the diagnosis of infection caused by the Epstein-Barr virus (in serum samples, saliva and urine) non-invasively in rapid tests evaluating their sensitivity, selectivity, specificity, speed and low cost. / O vírus Epstein Barr (EBV) é estudado neste projeto por estabelecer uma relação de latência com o organismo infectado e a uma série de fisiopatologias. Seu potencial oncogênico está relacionado às evidências sorológicas da presença do agente viral em neoplasias e também às doenças autoimunes como a Artrite Reumatoide e o Lúpus Eritematoso. Processos de detecção são necessários e têm despertado interesse científico nas últimas décadas, sendo importantes ferramentas analíticas usadas para diagnóstico clínico, controle de doenças, alterações fisiológicas, dentre outras. Mediante o exposto, dois genossensores foram desenvolvidos visando o reconhecimento específico do EBV pela eletroquímica. O pico de oxidação do brometo de etídio nos eletrodos de grafite modificados com poli(4-ATF) e o pico de redução de tetrametilbenzindina, como novo indicador de hibridização de oligonucleotídeos, nos eletrodos de grafite modificados com poli(4-AF) foram projetados e avaliados nestas plataformas. Análises de Ressonância de Plasmon de Superfície (SPR) e Microscopia de Força Atômica (AFM) foram utilizadas para complementar o estudo a fim de fundamentação teórica e prática. A perspectiva deste projeto é a aplicação no diagnóstico da infecção causada pelo vírus Epstein-Barr (em amostras de soro, saliva e urina) de forma não invasiva em testes rápidos avaliando sua sensibilidade, seletividade, especificidade, rapidez e de baixo custo. / Doutor em Genética e Bioquímica