Microssistemas de análises químicas: introdução, tecnologias de fabricação, instrumentação e aplicações

Coltro, Wendell Karlos Tomazelli; Piccin, Evandro; Carrilho, Emanuel; Jesus, Dosil Pereira de; Silva, José Alberto Fracassi da; Silva, Heron Domingues Torres da; Lago, Claudimir Lúcio do

doi:10.1590/s0100-40422007000800034

Cited by 28 publications

(33 citation statements)

References 118 publications

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“…Glass/ toner microchips were produced according to fabrication technology described by Do Lago et al 22 PDMS microchips were fabricated using the well-established soft-lithographic protocol, where a master is produced and microchannels are replicated via direct polymerization over the master. 23 The high-relief master was fabricated in the Laboratory of Microfabrication at the National Synchrotron Light Source (LNLS, Campinas, SP, Brazil) using standard photolithographic protocols. In this case, metallic nickel was electrodeposited onto an alumina substrate using UV-LIGA process.…”

Section: Microfluidic Devices Fabricationmentioning

confidence: 99%

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Visible LED-Based Instrumentation for Photometric Determination of Electroosmotic Flow in Microchannels

Silva¹,

Deblire²,

Jesus³

et al. 2011

J. Braz. Chem. Soc.

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A instrumentação para a determinação fotométrica do fluxo eletrosmótico (EOF) em dispositivos microfluídicos é descrita neste trabalho. A instrumentação é baseada em componentes acessíveis e consiste em um microscópio trinocular e no fotodiodo integrado OPT101. Um diodo emissor de luz (LED) de alta intensidade foi utilizado como fonte de radiação. Para as determinações foram utilizadas soluções aquosas dos corantes azul patente V e azul de metileno. O sistema foi utilizado no monitoramento do EOF em microdispositivos de poli(dimetilsiloxano) (PDMS) e híbridos de toner/vidro. As mobilidades do EOF determinadas em pH 7,0 foram (5,75 ± 0,01)10 -4 cm 2 V -1 s -1 e (3,2 ± 0,1)10 -4 cm 2 V -1 s -1 para os dispositivos de toner/vidro e PDMS, respectivamente. Medidas reprodutíveis foram obtidas em todos os experimentos, levando a uma alta precisão na determinação. O método proposto foi comparado com o método tradicional de determinação do EOF que envolve a medida da corrente nos microcanais.An instrumental setup for electroosmotic flow (EOF) determination in microfluidic devices is described. The system is based on a trinocular microscope and an integrated photodiode OPT101. The radiation was provided by a high-intensity white LED. For the determinations, patent blue V and methylene blue aqueous solutions were used. The setup was applied for EOF monitoring in hybrid toner/glass and PDMS microchips. For the toner/glass device, the EOF mobility was determined to be (5.75 ± 0.01) 10 -4 cm 2 V -1 s -1 at pH 7.0. For PDMS devices the measured EOF mobility was (3.2 ± 0.1) 10 -4 cm 2 V -1 s -1 . Reproducible measurements were obtained in all experiments, which produced results with small errors. The proposed method was compared to the conventional current monitoring method.Keywords: electroosmotic flow, mTAS, Lab-on-a-chip, photometric methods, microfluidic devices IntroductionElectroosmotic flow (EOF) is the movement of solvent molecules caused by an applied voltage in a capillary system. EOF plays an essential role in electromigration separation techniques, such as capillary zone electrophoresis (CZE or free solution capillary electrophoresis, FSCE) or microchip electrophoresis, 1 since the velocity of the ions is influenced by the magnitude of the EOF. As an example, both positively and negatively charged species can be simultaneously analyzed due to the EOF. Moreover, the EOF magnitude could bring some information about the condition of the surface of the capillary or microchannel wall. In particular, the knowledge about the surface charge density (including not only the EOF magnitude but also the zeta potential) can be of paramount importance for preventing adsorption of analyte to the wall.It is well accepted that EOF has its origin on the unbalanced charge distribution in the region closer to the capillary/microchannel wall, the so called electrical double layer (EDL). More precisely, the flow is caused by the movement of excess ions in the diffuse portion of the EDL. Mathematical treatment of the EOF combines the Newto...

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Section: Microfluidic Devices Fabricationmentioning

confidence: 99%

“…In this case, metallic nickel was electrodeposited onto an alumina substrate using UV-LIGA process. 23 In this work, glass/toner microchannels were produced with 100 mm width, 12 mm deep, and 6 cm long. In addition, PDMS microchannels were fabricated with 100 mm width, 60 mm deep, and 4 cm long.…”

Section: Microfluidic Devices Fabricationmentioning

confidence: 99%

Visible LED-Based Instrumentation for Photometric Determination of Electroosmotic Flow in Microchannels

Silva¹,

Deblire²,

Jesus³

et al. 2011

J. Braz. Chem. Soc.

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“…Miniaturization has become a important factor in all spheres of modern society, reflected strongly in science and technology, including electronics [1], medicine [2], chemistry [3,4] and other areas [5,6]. Miniaturization in chemistry was given a new dimension in the 1990s with the concepts of lab-on-a-chip and micro-total analysis systems ([ TAS) [7][8][9][10][11].…”

Section: Trends In Miniaturizationmentioning

confidence: 99%

Portable capillary-based (non-chip) capillary electrophoresis

Ryvolová

Preisler

Brabazon

et al. 2010

TrAC Trends in Analytical Chemistry

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Miniaturized, portable instrumentation has been gaining popularity in all areas of analytical chemistry. Capillary electrophoresis (CE), due to its main strengths of high separation efficiency, relatively short analysis time and low consumption of chemicals, is a particularly suitable technique for use in portable analytical instrumentation. In line with the general trend in miniaturization in chemistry utilizing microfluidic chips, the main thrust of portable CE (P-CE) systems development is towards chip-based miniaturized CE. Despite this, capillary-based (non-chip) P-CE systems have certain unmatched advantages, especially in the relative simplicity of the regular cylindrical geometry of the CE capillary, maximal volume-to-surface ratio, no need to design and to fabricate a chip, the low costs of capillary compared to chip, and better performance with some detection techniques. This review presents an overview of the state of the art of P-CE and literature relevant to future developments. We pay particular attention to the development and the potential of miniaturization of functional parts for P-CE. These include components related to sample introduction, separation and detection, which are the key elements in P-CE design. The future of P-CE may be in relatively simple, rugged designs (e.g., using a short piece of capillary fixed to a chip-sized platform on which injection and detection parts can be mounted). Electrochemical detection is well suited for miniaturization, so is probably the most suitable detection technique for P-CE, but optical detection is gaining interest, especially due to miniaturized light sources (e.g., light-emitting diodes).

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“…Com isso foi observado também algumas vantagens tais como: a redução do volume de reagentes e amostras, baixo custo no processo de fabricação dos dispositivos miniaturizados e redução no tempo de análise e síntese (COLTRO et al, 2007). Em tal sentido a miniaturização é explorada em diversas áreas da Ciência com intenção de respeitar os princípios básicos da química verde.…”

Section: Introductionunclassified

“…Na equação de Reynolds, ⍴ é a densidade do fluido, é a velocidade de escoamento, ℎ é diâmetro hidráulico da tubulação e é a viscosidade do fluído (SQUIRES e QUAKE, 2005;ÖZBEY et al, 2016;SUN et al, 2016 (DITTRICH, 2005;WHITESIDES, 2006;COLTRO et al, 2007). Um dos grandes desafios da microfabricação é conseguir projetar um reator microfluídico com geometria adequada para otimizar a eficiência de mistura e a transferência de massa e calor com base nas características de uma reação especifica.…”

Section: Introductionunclassified

Síntese Em Sistemas Microfluídicos De Nanopartículas De Cdte E De Ag Para Estudo Qualitativo De Interação Em Fluxo E Preparação De Filmes Finos Desses Nanomateriais

LIMA¹

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Microssistemas de análises químicas: introdução, tecnologias de fabricação, instrumentação e aplicações

Cited by 28 publications

References 118 publications

Visible LED-Based Instrumentation for Photometric Determination of Electroosmotic Flow in Microchannels

Visible LED-Based Instrumentation for Photometric Determination of Electroosmotic Flow in Microchannels

Portable capillary-based (non-chip) capillary electrophoresis

Síntese Em Sistemas Microfluídicos De Nanopartículas De Cdte E De Ag Para Estudo Qualitativo De Interação Em Fluxo E Preparação De Filmes Finos Desses Nanomateriais

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