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In vitro biomineralization by osteoblast-like cells : Part II - characterisation of cellular culture supernatants

Morais, S.; Carvalho, G.S.; Faria, Joaquim; Gomes, Helder; Sousa, João
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
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The quantification of total calcium, phosphorus, iron, chromium and nickel in cell culture medium by electrochemical or spectroscopic means may require digestion of samples. Nevertheless, when pH adjustment is performed for values higher than about 6.5, the formation of two phases occurs: a white precipitate and a clear solution. Analysing both phases using microelectrodes, atomic absorption spectrometry (AAS), diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, X-ray dispersive (XRD) analysis, scanning electron microscopy (SEM) and energy dispersive spectroscopic (EDS) analysis, it was observed that iron, chromium and nickel are not co-precipitating with the white solid phase. If quantification of calcium, phosphorus and magnesium is intended, a ten-fold dilution at least, must be performed to avoid most of these elements going into the precipitate. This knowledge is crucial if a mineralization study is going to be made.

Microelectrode arrays: application in batch-injection analysis

Fungaro, Denise A.; Brett, Christopher M. A.
Fonte: Universidade de Coimbra Publicador: Universidade de Coimbra
Tipo: Artigo de Revista Científica Formato: aplication/PDF
ENG
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The application of microelectrode arrays in electrochemical batch-injection analysis, injection volumes<=100 [mu]l, has been investigated using a random array of microdisks (RAM) electrode made with carbon fibres. Preliminary batch-injection experiments involving hexacyanoferrate(II) oxidation, using fixed-potential amperometry and cyclic voltammetry, showed the expected lesser dependence on injection flow rate and the steady-state current characteristics of the RAM electrode, compared to results from similar experiments at macroelectrodes. After electrodepositing mercury on the carbon fibre disks, square wave anodic stripping voltammetry of the test of heavy metals zinc, cadmium and lead was carried out by batch-injection analysis. It was found that the accumulation time of the metals influenced the response to a greater extent than at macroelectrodes, that the influence on the injected volume was similar to that at macroelectrodes and the influence of injection flow rate was less. Detection limits are improved at the RAM electrode; sensitivity as a function of normalised electrode area is also enhanced. Experiments in which the RAM electrode was covered by a thin Nafion film before carrying out BIA-SWASV were also performed, and showed similar trends. Although BIA can be performed directly on real samples without added electrolyte...

Estudos de sistemas micelares usando voltametria com microeletrodos; Studies of micellar systems with microelectrode voltammetry

Ferreira, Tiago Luiz
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 04/08/2008 PT
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Neste trabalho são apresentados resultados sobre o uso da voltametria com microeletrodos para o estudo de sistemas micelares. Estes estudos se basearam na obtenção de coeficientes de difusão de micelas em solução aquosa. Para tanto, o ferroceno foi utilizado como sonda eletroativa, haja vista que esta molécula é pouco solúvel em água e possui grande afinidade pelo interior micelar. A partir de experimentos envolvendo o tensoativo brometo de hexadecil trimetil amônio (C16TABr) pôde-se calcular parâmetros como o coeficiente de difusão do agregado na concentração micelar crítica e o coeficiente de interação intermicelar com a aplicação dos dados de coeficiente de difusão obtidos pela teoria de interação linear. O coeficiente de interação intermicelar permitiu a estimativa da concentração de eletrólito necessária para a mudança morfológica da micela (micela esférica para micela alongada). O raio hidronâmico da micela foi o calculado a partir da relação Stokes-Einstein. Um estudo complementar envolveu a adição de n-decanol à solução de tensoativo, e comparações dos coeficientes de difusão obtidos na presença e na ausência do álcool foram efetuadas. Estudos subseqüentes foram realizados empregando outros tensoativos (C14TABr...

Eletrossíntese e caracterização de filmes de polipirrol-2-ácido carboxílico para uso em biossensores amperométricos construídos em eletrodos miniaturizados; Electrosynthesis and characterizations of polypyrrole-2-carboxylic acid for application as amperometric biosensor constructed in microelectrodes

Foschini, Mauricio
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 05/06/2009 PT
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Neste trabalho, apresentamos a eletrossíntese de um novo polímero condutor derivado do polipirrol (PPI) funcionalizado com um grupo carboxílico, o polipirrol-2-ácido carboxílico (PPI-2-COOH), e o seu uso como transdutor amperométrico em biossensores pelo uso da polifenol oxidase (PFO). São apresentadas todas as etapas de síntese e de caracterização dos filmes poliméricos em microeletrodos e o preparo e a resposta dos biossensores montados para a detecção de um composto fenólico. Nossos estudos sobre eletrossíntese, respostas eletroquímicas dos filmes, juntamente com resultados de microgravimetria e modelagem molecular de dímeros e trímeros derivados de PI-2-COOH, permitiram com que pudéssemos sugerir pela primeira vez um mecanismo de eletropolimerização deste monômero em meio não aquoso. Na caracterização dos filmes por espectroscopia in situ no UV-visível e infravermelho próximo foram observadas duas bandas idênticas às transições pi-pi* características dos filmes de PPI no seu estado neutro e de maior dopagem, confirmando a possibilidade de haver duas conformações na cadeia do PPI-2-COOH. Com a modelagem molecular de um oligômero formado a partir da oxidação do PI-2-COOH, verificamos que para cada 4 anéis heterocíclicos acoplados entre si na posição 4-5...

Label-free DNA detection of hepatitis C virus based on modified conducting polypyrrole films at microelectrodes and atomic force microscopy tip-integrated electrodes

Riccardi, Carla dos Santos; Kranz, Christine; Kowalik, Janusz; Yamanaka, Hideko; Mizaikoff, Boris; Josowicz, Mira
Fonte: Amer Chemical Soc Publicador: Amer Chemical Soc
Tipo: Artigo de Revista Científica Formato: 237-245
ENG
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We present a new strategy for the label-free electrochemical detection of DNA hybridization for detecting hepatitis C virus based on electrostatic modulation of the ion-exchange kinetics of a polypyrrole film deposited at microelectrodes. Synthetic single-stranded 18-mer HCV genotype-1-specific probe DNA has been immobilized at a 2,5-bis(2-thienyl)-N-(3-phosphoryl-n-alkyl)pyrrole film established by electropolymerization at the previously formed polypyrrole layer. HCV DNA sequences (244-mer) resulting from the reverse transcriptase-linked polymerase chain reaction amplification of the original viral RNA were monitored by affecting the ion-exchange properties of the polypyrrole film. The performance of this miniaturized DNA sensor system was studied in respect to selectivity, sensitivity, and reproducibility. The limit of detection was determined at 1.82 x 10(-21) mol L-1. Control experiments were performed with cDNA from HCV genotypes 2a/c, 2b, and 3 and did not show any unspecific binding. Additionally, the influence of the spacer length of 2,5-bis(2-thienyl)-N-(3-phosphoryl-n-alkyl)pyrrole on the behavior of the DNA sensor was investigated. This biosensing scheme was finally extended to the electrochemical detection of DNA at submicrometer-sized DNA biosensors integrated into bifunctional atomic force scanning electrochemical microscopy probes. The 18-mer DNA target was again monitored by following the ion-exchange properties of the polypyrrole film. Control experiments were performed with 12-base pair mismatched sequences.

Microeletrodos: I. Construção e caracterização

Fertonani, Fernando Luís; Benedetti, Assis Vicente
Fonte: Editora Unesp Publicador: Editora Unesp
Tipo: Artigo de Revista Científica Formato: 147-169
POR
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Estudou-se e discutiu-se os diferentes métodos de preparação de microfios de Pt pura, Pt-Ir (20%, m/m) e Pt-Rh (10%, m/m) a serem empregados na construção dos respectivos microeletrodos. Os fios de Pt e suas ligas foram obtidos empregando fieiras com diferentes diâmetros. em seguida foi utilizado o procedimento de desgaste eletroquímico em sal fundido (mistura NaNO3/ NaCl 14: a 320oC) para a Pt e em solução 6 molL-1 NaCN + 2 mol L-1 NaOH para a liga de Pt-Ir. Para a caracterização da interface metal-vidro e determinação dos raios geométrico e efetivo foram empregadas as microscopias óptica e eletrônica de varredura, a voltametria cíclica e a cronoamperometria. A condição de selagem foi verificada através dos gráficos da capacitância aparente Cd, corrigida considerando-se a área dos microeletrodos, e a velocidade de varredura, v.; Platinum, platinum-iridium (20 wt.%) and platinum-rhodium (10 wt.%) alloys were prepared as microwires using different methods. Microwires of Pt and its alloys with several diameters were prepared by passing wires of 1 mm of diameter through a drawplate. Afterwards...

Label-free DNA detection based on modified conducting polypyrrole films at microelectrodes

Riccardi, C. D.; Yamanaka, H.; Josowicz, M.; Kowalik, J.; Mizaikoff, B.; Kranz, C.
Fonte: Amer Chemical Soc Publicador: Amer Chemical Soc
Tipo: Artigo de Revista Científica Formato: 1139-1145
ENG
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A label-free electrochemical detection method for DNA hybridization based on electrostatic modulation of the ion-exchange kinetics of a polypyrrole film deposited at microelectrodes is reported. Synthetic single-stranded 27-mer oligonucleotides (probe) have been immobilized at 2,5-bis(2-thienyl)-N-(3-phosphorylpropyl)pyrrole film formed by electropolymerization on the previously formed polypyrrole layer. The 27- or 18-mer target oligonucleotides were monitored via the electrochemically driven anion exchange of the inner polypyrrole film. The performance of the miniaturized DNA biosensor system was studied in respect to selectivity, sensitivity, reproducibility, and regeneration of the sensor. Control experiments were performed with a noncomplementary target of 27-mer DNA and 12 base-pair mismatched 18-mer sequences, respectively, and did not show any unspecific binding. Under optimized experimental conditions, the label-free electrochemical biosensor enabled the detection limits of 0.16 and 3.5 fmol for the 18- and 2 7-mer DNA strand, respectively. Furthermore, we demonstrate reusability of the electrochemical DNA biosensor after successful recovery of up to 100% of the original signal by regenerating the DNA label-free electrode with 50 mM HCl at room temperature.

Flow-through cell based on an array of gold microelectrodes obtained from modified integrated circuit chips

Augelli, M. A.; Nascimento, V. B.; Pedrotti, J. J.; Gutz, IGR; Angnes, L.
Fonte: Royal Soc Chemistry Publicador: Royal Soc Chemistry
Tipo: Artigo de Revista Científica Formato: 843-847
ENG
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The construction of a flow-through cell incorporating an array of gold microelectrodes is described and its application to flow injection analysis with amperometric detection is presented, Simple modification of almost any conventional integrated circuit chip, used as an inexpensive source of pre-assembled gold micro-wires, leads to the rapid and successful preparation of arrays of 8-48 elements, the polymeric encapsulation material from the top face of the chip is removed by abrasion until the gold micro-mires (used to interconnect the silicon circuit to the external contact pins of the chip) are disrupted and their transversal (elliptical) sections become exposed. Once polished, the flat and smooth top surface of the gold microelectrode-array chip (MEAC) is provided with a spacer and fitted under pressure against an acrylic block with the reference and auxiliary electrodes, to form the electrochemical (thin-layer) flow cell, while the contact pins are plugged into a standard IC socket, This design ensures autonomous electric contact with each electrode and allows fast dismantling for polishing or substitution, the performance of flow cells with MEACs was investigated utilizing the technique of reverse pulse amperometry without oxygen removal...

Effect of the medium composition on the current of steady state voltammograms of neutral and charged species in dimethylformamide/toluene mixtures

Bento, M. Fátima; Geraldo, M. Dulce; Montenegro, M. I.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em /04/1999 ENG
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Steady state voltammetric currents of both neutral and charged species obtained at microelectrodes are affected by the medium composition. Experiments carried out in N,N-dimethylformamide (DMF) and toluene/DMF mixtures for the reduction of diciano(fluoren-9-ylidene)methane and the methylviologen cation and for the oxidation of ferrocene, in the presence of different electrolyte concentrations indicate that both viscosity of the solution and mass transport by migration may have a strong effect on the measured limiting currents. These observations are particularly important in electroanalysis since the appropriate choice of the medium may substantially improve both the sensitivity and the detection limits of the electrochemical method.; FEDER. PRAXIS/2/2.1/QUI /260/94.

Evaluation of the lactic acid consumption in yeast cultures by voltammetric means

Rodrigues, Astride; Bento, M. Fátima; Geraldo, M. Dulce; Cássio, Fernanda
Fonte: Wiley-VCH Verlag Berlin Publicador: Wiley-VCH Verlag Berlin
Tipo: Artigo de Revista Científica
Publicado em /03/2005 ENG
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The voltammetric study of the lactic acid reduction was performed in media suitable for yeast growth, using platinum microelectrodes. The decrease of the voltammetric peak current from square wave voltammetry, variation of Ip, in cultures of the yeasts Candida utilis and Saccharomyces cerevisiae was related to both the growth time and cellular biomass. Either the imposed variations of medium composition or those resulting from cellular growth did not significantly affect the variation of Ip values. For both yeast species, similar specific growth rates were estimated from the variation of Ip and absorbance at 640 nm.; POCTI/QUI/39525/2001.

Voltammetric analysis of weak acids with microelectrodes

Canhoto, Carla; Matos, Mara; Rodrigues, Astride; Geraldo, M. Dulce; Bento, M. Fátima
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em /08/2004 ENG
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The role of H+ on the steady-state voltammetric limiting current (IL) of weak acids (HA) reduction was studied considering results from either lactic acid or acetic acid solutions at constant pH. For solutions with pH > pKa or pH near pKa the [H+] effect on the IL vs cHA slope was important even when the H+ current contribution was minor. In opposition, when pH << pKa high H+ current contributions were found nevertheless the IL vs cHA slope was almost insensitive to pH. A general relationship between IL and cHA was derived considering both the H+ current contribution and the dissociation extent. This equation allows the analytical determination of weak acids, alone or in the presence of strong acids, from experimental IL and pH. Acids identification can also be performed through the presented expression, following the IL susceptibility to pH at constant cHA.; POCTI/QUI/ 39525/2001.

Determinação da densidade de corrente de corrosão em meios de baixa condutividade: uso de microeletrodos para minimizar a queda ôhmica

Oliveira,Paulo César A. de; Bertazzoli,Rodnei
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2011 PT
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The gravimetric and electrochemical tests are the most common techniques used in determining the corrosion rate. However, the use of electrochemical polarization is limited to electrolytes with sufficient conductivity for which Tafel curves are linear. In this study, we investigated a technique in which working microelectrodes of AISI 1020 steel were used to obtain the Tafel curves in diesel oil. The strategy was to reduce the electrode area and hence the ohmic drop. The diameter of the microelectrode was reduced to a value where the compensation of the Tafel curves became unnecessary. The results showed that for electrodes with diameters below 50 μm, the ohmic drop tends to a minimum and independent of the microelectrode diameter.

A study of nitrite oxidation at platinum microelectrodes

Bertotti,Mauro; Pletcher,Derek
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/1997 EN
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The anodic oxidation of nitrite at Pt microdisc electrodes (radii 5-25 mm) has been studied. It is shown that the electrode reaction is not simple and the response is determined by the oxide coverage of the surface. It is, however, possible to define conditions for the amperometric determination of nitrite in neutral, aqueous chloride solutions; once the electrode surface is preconditioned, the method is rapid and simple and has a lowest detection limit of » 2 mM.

Investigation of the Apparent Induction of Nitrate Uptake in Barley (Hordeum vulgare L.) Using NO3--Selective Microelectrodes (Modulation of Coarse Regulation of NO3- Uptake by Exogenous Application of Downstream Metabolites in the NO3- Assimilatory Pathway).

Henriksen, G. H.; Spanswick, R. M.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /11/1993 EN
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The influence of a 12-h pretreatment with either NO3-, NH4+, glutamine, or glutamate (300 [mu]M) on the apparent induction of NO3- uptake was investigated. Net fluxes of NO3- into roots of intact, 7-d-old barley (Hordeum vulgare L. cv Prato) seedlings in solution culture were estimated from ion activity gradients measured with NO3--selective microelectrodes in the unstirred layer of solution immediately external to the root surface. Control plants, pretreated with nitrogen-free nutrient solution, exhibited a sigmoidal increase in net NO3- uptake, reaching a maximum rate between 8 and 9 h after first exposure to NO3-. Plants pretreated with NH4+ or Glu exhibited a delay of several hours in the initiation of the induction process after they had been exposed to NO3-. In Gln-pretreated plants, however, responses ranged from no delay of the induction process to delays comparable to those observed following NH4+ or Glu pretreatments. Only treatment with NO3-resulted in the induction of NO3- uptake, whereas pretreatments with NH4+, Gln, or Glu tended to delay induction of NO3- uptake upon subsequent exposure to NO3-.

Distribution of sulfate-reducing bacteria, O2, and H2S in photosynthetic biofilms determined by oligonucleotide probes and microelectrodes.

Ramsing, N B; Kühl, M; Jørgensen, B B
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /11/1993 EN
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The vertical distribution of sulfate-reducing bacteria (SRB) in photosynthetic biofilms from the trickling filter of a sewage treatment plant was investigated with oligonucleotide probes binding to 16S rRNA. To demonstrate the effect of daylight and photosynthesis and thereby of increased oxygen penetration, we incubated two 4-mm-thick biofilm samples in darkness or exposed to light at natural intensity. Gradients of O2, H2S, and pH were examined with microelectrodes during incubation. The samples were subsequently frozen with liquid nitrogen and sliced on a cryomicrotome in 20-microns vertical slices. Fluorescent-dye-conjugated oligonucleotides were used as "phylogenetic" probes to identify single cells in the slices. Oligonucleotide sequences were selected which were complementary to short sequence elements (16 to 20 nucleotides) within the 16S rRNA of sulfate-reducing bacteria. The probes were labeled with fluorescein or rhodamine derivatives for subsequent visualization by epifluorescence microscopy. Five probes were synthesized for eukaryotes, eubacteria, SRB (including most species of the delta group of purple bacteria), Desulfobacter spp., and a nonhybridizing control. The SRB were unevenly distributed in the biofilm, being present in all states from single scattered cells to dense clusters of several thousand cells. To quantify the vertical distribution of SRB...

Chloride and Potassium Activities in Luminal Fluid of Turtle Thyroid Follicles as Determined by Selective Ion-Exchanger Microelectrodes

Chow, S. Y.; Kunze, D.; Brown, A. M.; Woodbury, D. M.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1970 EN
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Cl- and K+ activities in the follicular lumen and the intraluminal potential of the same lumen were measured simultaneously with specific liquid ion-exchanger and 3 M KCl microelectrodes, respectively, in turtle thyroid glands. The Cl- equilibrium potential between the thyroid interstitium and the lumen calculated from the measured Cl- activities was higher than the directly measured intraluminal potential. These data indicate that Cl- is actively transported out of the follicular lumen in turtle thyroid gland. On the other hand, the calculated K+ equilibrium potential was not different from the directly measured potential, which indicates that K+ is probably distributed passively according to the electrochemical gradients between the interstitial and the luminal compartments in turtle thyroid gland. Results obtained from the specific liquid ion-exchanger microelectrode studies correlate well with those obtained from previous radioautographic observations and chemical determinations.

Microelectrodes Suitable for Use in Cells with High Hydrostatic Pressure 1

Ernau, Mildred C.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1974 EN
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Microelectrodes with a 1- to 2-μm tip diameter have been made which are capable of withstanding plant cell hydrostatic pressure on impalement. Filling the electrodes with 1% agar or 5% gelatin in 2 m KCl prevents cytoplasmic contents from moving into the electrode tip on impalement and therefore prevents the irreversible increase in resistance which often occurs. The agar and gelatin electrodes were tested in two fresh water algae, Nitella translucens and Mougeotia sp., and the potentials recorded were found comparable to those recorded with standard 2 m KCl electrodes.

A Numerical Study to Compare Stimulations by Intraoperative Microelectrodes and Chronic Macroelectrodes in the DBS Technique

Paffi, A.; Apollonio, F.; Puxeddu, M. G.; Parazzini, M.; d'Inzeo, G.; Ravazzani, P.; Liberti, M.
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
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Deep brain stimulation is a clinical technique for the treatment of parkinson's disease based on the electric stimulation, through an implanted electrode, of specific basal ganglia in the brain. To identify the correct target of stimulation and to choose the optimal parameters for the stimulating signal, intraoperative microelectrodes are generally used. However, when they are replaced with the chronic macroelectrode, the effect of the stimulation is often very different. Here, we used numerical simulations to predict the stimulation of neuronal fibers induced by microelectrodes and macroelectrodes placed in different positions with respect to each other. Results indicate that comparable stimulations can be obtained if the chronic macroelectrode is correctly positioned with the same electric center of the intraoperative microelectrode. Otherwise, some groups of fibers may experience a completely different electric stimulation.

Biosensing at disk microelectrode arrays. Inter-electrode functionalization allows formatting into miniaturised sensing platforms of enhanced sensitivity.

Baldrich, Eva; Campo García, Francisco Javier del; Muñoz, Francesc Xavier
Fonte: Conselho Superior de Investigações Científicas Publicador: Conselho Superior de Investigações Científicas
Tipo: Artículo Formato: 694736 bytes; application/pdf
ENG
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En este trabajo demostramos el uso de redes de microelectrodos como base para el desarrollo de biosensores. La principal ventaja está en que las biomoléculas empleadas para reconocer los analitos se inmovilizan en la parte inerte de la red. Es decir, en el espacio entre microelectrodos. De este modo los electrodos pueden mantenerse activos y conservar su alta sensibilidad.; Biosensor performance depends on the effective functionalisation of a transducer with suitable biorecognition elements. During functionalisation, surface blocking steps are normally carried out to avoid later binding of undesirable molecules and thus guarantee biosensor specificity. However, these blocking steps may be deleterious in electrochemical systems where transduction ultimately relies on electron transfer between the electrode and a redox species in solution. This work presents a novel approach to develop improved amperometric biosensing platforms using microfabricated disk microelectrode arrays, based on the functionalisation of the inert surface surrounding the active microdisks. These devices more than doubled assay sensitivity compared to conventional biosensors produced using the same arrays. This approach benefits from three advantages: the functionalisation of a broader surface...

Fabricação de matrizes multieletrodos de 60 canais para futuro uso em culturas de células neurais; Fabrication of 60 channel multielectrode arrays for future use with cultured neuronal networks

Vanessa Pereira Gomes
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 10/09/2015 PT
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Uma área que está em crescente desenvolvimento reside no campo da neurociência básica, a estimulação e gravação das células nervosas. A possibilidade da aplicação da microtecnologia e os avanços nas ciências de materiais têm permitido gerar dispositivos cada vez mais sofisticados e com maiores funcionalidades. Neste cenário surgem as matrizes multieletrodos (MEAs), dispositivos que atuam como interface cérebro-computador, no qual a rede de microeletrodos faz a comunicação mundo eletrônico - células (que geram o potencial de ação), têm atraído atenção. Com base nisso, este projeto tem como objetivo construir uma MEA de 60 canais para uso (registro e estimulação extracelular in vitro) em culturas de células neurais. Para tanto, inicialmente, foi produzido um conjunto de máscaras, que contêm os padrões utilizados na obtenção dos dispositivos através da técnica de fotolitografia. Na sequência, o procedimento experimental mostra as etapas de microfabricação de dois protótipos de teste denominados MEA1 e MEA2. Apresentamos as etapas de formação da intercamada, e de fotolitografia para formação dos eletrodos, trilhas, pads de contato e isolação, e a finalização do protótipo (colocação do anel de vidro). Assim...