1
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Ben Frej M, d'Orlyé F, Duarte‐Junior GF, Coltro WKT, Varenne A. Electrokinetic characterization of hybrid NOA 81‐glass microchips: Application to protein microchip electrophoresis with indirect fluorescence detection. Electrophoresis 2022; 43:2044-2048. [DOI: 10.1002/elps.202200057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 07/08/2022] [Accepted: 07/15/2022] [Indexed: 11/10/2022]
Affiliation(s)
- Menel Ben Frej
- Institute of Chemistry for Life and Health Sciences i‐CLeHS Chimie ParisTech‐PSL/CNRS 8060 Paris France
| | - Fanny d'Orlyé
- Institute of Chemistry for Life and Health Sciences i‐CLeHS Chimie ParisTech‐PSL/CNRS 8060 Paris France
| | - Gerson F. Duarte‐Junior
- Institute of Chemistry for Life and Health Sciences i‐CLeHS Chimie ParisTech‐PSL/CNRS 8060 Paris France
- Instituto de Química Universidade Federal de Goiás Goiânia Brazil
| | | | - Anne Varenne
- Institute of Chemistry for Life and Health Sciences i‐CLeHS Chimie ParisTech‐PSL/CNRS 8060 Paris France
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2
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Abstract
Isotachophoresis (ITP) is a versatile electrophoretic technique that can be used for sample preconcentration, separation, purification, and mixing, and to control and accelerate chemical reactions. Although the basic technique is nearly a century old and widely used, there is a persistent need for an easily approachable, succinct, and rigorous review of ITP theory and analysis. This is important because the interest and adoption of the technique has grown over the last two decades, especially with its implementation in microfluidics and integration with on-chip chemical and biochemical assays. We here provide a review of ITP theory starting from physicochemical first-principles, including conservation of species, conservation of current, approximation of charge neutrality, pH equilibrium of weak electrolytes, and so-called regulating functions that govern transport dynamics, with a strong emphasis on steady and unsteady transport. We combine these generally applicable (to all types of ITP) theoretical discussions with applications of ITP in the field of microfluidic systems, particularly on-chip biochemical analyses. Our discussion includes principles that govern the ITP focusing of weak and strong electrolytes; ITP dynamics in peak and plateau modes; a review of simulation tools, experimental tools, and detection methods; applications of ITP for on-chip separations and trace analyte manipulation; and design considerations and challenges for microfluidic ITP systems. We conclude with remarks on possible future research directions. The intent of this review is to help make ITP analysis and design principles more accessible to the scientific and engineering communities and to provide a rigorous basis for the increased adoption of ITP in microfluidics.
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Affiliation(s)
- Ashwin Ramachandran
- Department of Aeronautics and Astronautics, Stanford University, Stanford, California 94305, United States
| | - Juan G Santiago
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
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3
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Versatile and Easily Designable Polyester-Laser Toner Interfaces for Site-Oriented Adsorption of Antibodies. Int J Mol Sci 2022; 23:ijms23073771. [PMID: 35409130 PMCID: PMC8998940 DOI: 10.3390/ijms23073771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/27/2022] [Accepted: 03/28/2022] [Indexed: 02/01/2023] Open
Abstract
Laser toners appear as attractive materials for barriers and easily laminated interphases for Lab-on-a-Foil microfluidics, due to the excellent adhesion to paper and various membranes or foils. This work shows for the first time a comprehensive study on the adsorption of antibodies on toner-covered poly(ethylene terephthalate) (PET@toner) substrates, together with assessment of such platforms in rapid prototyping of disposable microdevices and microarrays for immunodiagnostics. In the framework of presented research, the surface properties and antibody binding capacity of PET substrates with varying levels of toner coverage (0–100%) were characterized in detail. It was proven that polystyrene-acrylate copolymer-based toner offers higher antibody adsorption efficiency compared with unmodified polystyrene and PET as well as faster adsorption kinetics. Comparative studies of the influence of pH on the effectiveness of antibodies immobilization as well as measurements of surface ζ-potential of PET, toner, and polystyrene confirmed the dominant role of hydrophobic interactions in adsorption mechanism. The applicability of PET@toner substrates as removable masks for protection of foil against permanent hydrophilization was also shown. It opens up the possibility of precise tuning of wettability and antibody binding capacity. Therefore, PET@toner foils are presented as useful platforms in the construction of immunoarrays or components of microfluidic systems.
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4
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Nguyen T, Chidambara VA, Andreasen SZ, Golabi M, Huynh VN, Linh QT, Bang DD, Wolff A. Point-of-care devices for pathogen detections: The three most important factors to realise towards commercialization. Trends Analyt Chem 2020. [DOI: 10.1016/j.trac.2020.116004] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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5
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Moreira NS, Chagas CL, Oliveira KA, Duarte-Junior GF, de Souza FR, Santhiago M, Garcia CD, Kubota LT, Coltro WK. Fabrication of microwell plates and microfluidic devices in polyester films using a cutting printer. Anal Chim Acta 2020; 1119:1-10. [DOI: 10.1016/j.aca.2020.04.047] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 03/25/2020] [Accepted: 04/19/2020] [Indexed: 12/31/2022]
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6
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Keshmiri K, Huang H, Nazemifard N. Compatibility of poly(dimethylsiloxane) microfluidic systems with high viscosity hydrocarbons. SN APPLIED SCIENCES 2019. [DOI: 10.1007/s42452-019-0666-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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7
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Blaschke S, Vay SU, Pallast N, Rabenstein M, Abraham JA, Linnartz C, Hoffmann M, Hersch N, Merkel R, Hoffmann B, Fink GR, Rueger MA. Substrate elasticity induces quiescence and promotes neurogenesis of primary neural stem cells-A biophysical in vitro model of the physiological cerebral milieu. J Tissue Eng Regen Med 2019; 13:960-972. [PMID: 30815982 DOI: 10.1002/term.2838] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 11/18/2018] [Accepted: 02/13/2019] [Indexed: 01/17/2023]
Abstract
In the brain, neural stem cells (NSC) are tightly regulated by external signals and biophysical cues mediated by the local microenvironment or "niche." In particular, the influence of tissue elasticity, known to fundamentally affect the function of various cell types in the body, on NSC remains poorly understood. We, accordingly, aimed to characterize the effects of elastic substrates on critical NSC functions. Primary rat NSC were grown as monolayers on polydimethylsiloxane- (PDMS-) based gels. PDMS-coated cell culture plates, simulating the physiological microenvironment of the living brain, were generated in various degrees of elasticity, ranging from 1 to 50 kPa; additionally, results were compared with regular glass plates as usually used in cell culture work. Survival of NSC on the PDMS-based substrates was unimpaired. The proliferation rate on 1 kPa PDMS decreased by 45% compared with stiffer PMDS substrates of 50 kPa (p < 0.05) whereas expression of cyclin-dependent kinase inhibitor 1B/p27Kip1 increased more than two fold (p < 0.01), suggesting NSC quiescence. NSC differentiation was accelerated on softer substrates and favored the generation of neurons (42% neurons on 1 kPa PDMS vs. 25% on 50 kPa PDMS; p < 0.05). Neurons generated on 1 kPa PDMS showed 29% longer neurites compared with those on stiffer PDMS substrates (p < 0.05), suggesting optimized neuronal maturation and an accelerated generation of neuronal networks. Data show that primary NSC are significantly affected by the mechanical properties of their microenvironment. Culturing NSC on a substrate of brain-like elasticity keeps them in their physiological, quiescent state and increases their neurogenic potential.
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Affiliation(s)
- Stefan Blaschke
- Department of Neurology, University Hospital Cologne, Cologne, Germany.,Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Juelich, Germany
| | - Sabine Ulrike Vay
- Department of Neurology, University Hospital Cologne, Cologne, Germany
| | - Niklas Pallast
- Department of Neurology, University Hospital Cologne, Cologne, Germany
| | - Monika Rabenstein
- Department of Neurology, University Hospital Cologne, Cologne, Germany
| | | | - Christina Linnartz
- Biomechanics Section, Institute of Complex Systems (ICS-7), Juelich, Germany
| | - Marco Hoffmann
- Biomechanics Section, Institute of Complex Systems (ICS-7), Juelich, Germany
| | - Nils Hersch
- Biomechanics Section, Institute of Complex Systems (ICS-7), Juelich, Germany
| | - Rudolf Merkel
- Biomechanics Section, Institute of Complex Systems (ICS-7), Juelich, Germany
| | - Bernd Hoffmann
- Biomechanics Section, Institute of Complex Systems (ICS-7), Juelich, Germany
| | - Gereon Rudolf Fink
- Department of Neurology, University Hospital Cologne, Cologne, Germany.,Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Juelich, Germany
| | - Maria Adele Rueger
- Department of Neurology, University Hospital Cologne, Cologne, Germany.,Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Juelich, Germany
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8
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Meyer S, Clarke C, dos Santos RO, Bishop D, Krieger MA, Blanes L. Developing self-generated calibration curves using a capillary-driven wax-polyester lab on a chip device and thermal gates. Microchem J 2019. [DOI: 10.1016/j.microc.2019.01.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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9
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Fontana F, Figueiredo P, Zhang P, Hirvonen JT, Liu D, Santos HA. Production of pure drug nanocrystals and nano co-crystals by confinement methods. Adv Drug Deliv Rev 2018; 131:3-21. [PMID: 29738786 DOI: 10.1016/j.addr.2018.05.002] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/01/2018] [Accepted: 05/03/2018] [Indexed: 11/26/2022]
Abstract
The use of drug nanocrystals in the drug formulation is increasing due to the large number of poorly water-soluble drug compounds synthetized and due to the advantages brought by the nanonization process. The downsizing processes are done using a top-down approach (milling and homogenization currently employed at the industrial level), while the crystallization process is performed by bottom-up techniques (e.g., antisolvent precipitation, use of supercritical fluids or spray and freeze drying). In addition, the production of nanocrystals in confined environment can be achieved within microfluidics channels. This review analyzes the processes for the preparation of nanocrystals and co-crystals, divided by top-down and bottom-up approaches, together with their combinations. The combination of both strategies merges the favorable features of each process and avoids the disadvantages of single processes. Overall, the applicability of drug nanocrystals is highlighted by the widespread research on the production processes at the engineering, pharmaceutical, and nanotechnology level.
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10
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Ghosh A, Vilorio CR, Hawkins AR, Lee ML. Microchip gas chromatography columns, interfacing and performance. Talanta 2018; 188:463-492. [PMID: 30029402 DOI: 10.1016/j.talanta.2018.04.088] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/25/2018] [Accepted: 04/26/2018] [Indexed: 11/30/2022]
Abstract
Almost four decades of investigations have opened up many avenues to explore the production and utilization of planar (i.e., microchip) gas chromatographic columns. However, there remain many practical constraints that limit their widespread commercialization and use. The main challenges arise from non-ideal column geometries, dead volume issues and inadequate interfacing technologies, which all affect both column performance and range of applications. This review reflects back over the years on the extensive developments in the field, with the goal to stimulate future creative approaches and increased efforts to accelerate microchip gas chromatography development toward reaching its full potential.
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Affiliation(s)
- Abhijit Ghosh
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA
| | - Carlos R Vilorio
- Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT 84602, USA
| | - Aaron R Hawkins
- Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT 84602, USA
| | - Milton L Lee
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA.
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11
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Morbioli GG, Mazzu-Nascimento T, Aquino A, Cervantes C, Carrilho E. Recombinant drugs-on-a-chip: The usage of capillary electrophoresis and trends in miniaturized systems – A review. Anal Chim Acta 2016; 935:44-57. [DOI: 10.1016/j.aca.2016.06.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 06/07/2016] [Accepted: 06/10/2016] [Indexed: 01/09/2023]
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12
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Lobo-Júnior EO, Gabriel EFM, dos Santos RA, de Souza FR, Lopes WD, Lima RS, Gobbi AL, Coltro WKT. Simple, rapid and, cost-effective fabrication of PDMS electrophoresis microchips using poly(vinyl acetate) as photoresist master. Electrophoresis 2016; 38:250-257. [DOI: 10.1002/elps.201600209] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/20/2016] [Accepted: 06/21/2016] [Indexed: 11/12/2022]
Affiliation(s)
| | | | | | | | | | - Renato S. Lima
- Laboratório Nacional de Nanotecnologia; Centro Nacional de Pesquisa em Energia e Materiais; Campinas/SP Brazil
| | - Angelo L. Gobbi
- Laboratório Nacional de Nanotecnologia; Centro Nacional de Pesquisa em Energia e Materiais; Campinas/SP Brazil
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14
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Abstract
The cost, time, and restrictions on creative flexibility associated with current fabrication methods present significant challenges in the development and application of microfluidic devices. Additive manufacturing, also referred to as three-dimensional (3D) printing, provides many advantages over existing methods. With 3D printing, devices can be made in a cost-effective manner with the ability to rapidly prototype new designs. We have fabricated a micro free-flow electrophoresis (μFFE) device using a low-cost, consumer-grade 3D printer. Test prints were performed to determine the minimum feature sizes that could be reproducibly produced using 3D printing fabrication. Microfluidic ridges could be fabricated with dimensions as small as 20 μm high × 640 μm wide. Minimum valley dimensions were 30 μm wide × 130 μm wide. An acetone vapor bath was used to smooth acrylonitrile-butadiene-styrene (ABS) surfaces and facilitate bonding of fully enclosed channels. The surfaces of the 3D-printed features were profiled and compared to a similar device fabricated in a glass substrate. Stable stream profiles were obtained in a 3D-printed μFFE device. Separations of fluorescent dyes in the 3D-printed device and its glass counterpart were comparable. A μFFE separation of myoglobin and cytochrome c was also demonstrated on a 3D-printed device. Limits of detection for rhodamine 110 were determined to be 2 and 0.3 nM for the 3D-printed and glass devices, respectively.
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Affiliation(s)
- Sarah K Anciaux
- Department of Chemistry, University of Minnesota , 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Matthew Geiger
- Department of Chemistry, University of Minnesota , 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Michael T Bowser
- Department of Chemistry, University of Minnesota , 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
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15
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Self-regenerating and hybrid irreversible/reversible PDMS microfluidic devices. Sci Rep 2016; 6:26032. [PMID: 27181918 PMCID: PMC4867595 DOI: 10.1038/srep26032] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 04/25/2016] [Indexed: 11/08/2022] Open
Abstract
This paper outlines a straightforward, fast, and low-cost method to fabricate polydimethylsiloxane (PDMS) chips. Termed sandwich bonding (SWB), this method requires only a laboratory oven. Initially, SWB relies on the reversible bonding of a coverslip over PDMS channels. The coverslip is smaller than the substrate, leaving a border around the substrate exposed. Subsequently, a liquid composed of PDMS monomers and a curing agent is poured onto the structure. Finally, the cover is cured. We focused on PDMS/glass chips because of their key advantages in microfluidics. Despite its simplicity, this method created high-performance microfluidic channels. Such structures featured self-regeneration after leakages and hybrid irreversible/reversible behavior. The reversible nature was achieved by removing the cover of PDMS with acetone. Thus, the PDMS substrate and glass coverslip could be detached for reuse. These abilities are essential in the stages of research and development. Additionally, SWB avoids the use of surface oxidation, half-cured PDMS as an adhesive, and surface chemical modification. As a consequence, SWB allows surface modifications before the bonding, a long time for alignment, the enclosure of sub-micron channels, and the prototyping of hybrid devices. Here, the technique was successfully applied to bond PDMS to Au and Al.
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16
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da Costa ET, Santos MFS, Jiao H, do Lago CL, Gutz IGR, Garcia CD. Fast production of microfluidic devices by CO2laser engraving of wax-coated glass slides. Electrophoresis 2016; 37:1691-5. [DOI: 10.1002/elps.201600065] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 03/04/2016] [Accepted: 03/16/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Eric T. da Costa
- Department of Chemistry, 219 Hunter Laboratories; Clemson University; Clemson SC USA
| | - Mauro F. S. Santos
- Department of Chemistry, 219 Hunter Laboratories; Clemson University; Clemson SC USA
- Instituto de Química, Universidade de São Paulo; São Paulo Brazil
| | - Hong Jiao
- HJ Science and Technology; Berkeley CA USA
| | | | - Ivano G. R. Gutz
- Instituto de Química, Universidade de São Paulo; São Paulo Brazil
| | - Carlos D. Garcia
- Department of Chemistry, 219 Hunter Laboratories; Clemson University; Clemson SC USA
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17
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OBORNY NJ, COSTA EEM, SUNTORNSUK L, ABREU FC, LUNTE SM. Evaluation of a Portable Microchip Electrophoresis Fluorescence Detection System for the Analysis of Amino Acid Neurotransmitters in Brain Dialysis Samples. ANAL SCI 2016; 32:35-40. [PMID: 26753703 PMCID: PMC4875779 DOI: 10.2116/analsci.32.35] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 11/09/2015] [Indexed: 01/08/2023]
Abstract
A portable fluorescence detection system for use with microchip electrophoresis was developed and compared to a benchtop system. Using this system, six neuroactive amines commonly found in brain dialysate (arginine, citrulline, taurine, histamine, glutamate, and aspartate) were derivatized offline with naphthalene-2,3-dicarboxaldehyde/cyanide, separated electrophoretically, and detected by fluorescence. The limits of detection for the analytes of interest were 50 - 250 nM for the benchtop system and 250 nM - 1.3 μM for the portable system, both of which were adequate for most analyte detection in brain microdialysis samples. The portable system was then demonstrated for the detection of the same six amines in a rat brain microdialysis sample.
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Affiliation(s)
- Nathan J. OBORNY
- Department of Bioengineering, University of Kansas, Lawrence, KS, USA
- Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, KS, USA
| | - Elton E. Melo COSTA
- Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, KS, USA
- Institute of Chemistry and Biotechnology, Federal University of Alagoas, Alagoas, Brazil
| | - Leena SUNTORNSUK
- Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, KS, USA
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand
| | - Fabiane C. ABREU
- Institute of Chemistry and Biotechnology, Federal University of Alagoas, Alagoas, Brazil
| | - Susan M. LUNTE
- Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, KS, USA
- Department of Chemistry, University of Kansas, Lawrence, KS, USA
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18
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Recent applications of microchip electrophoresis to biomedical analysis. J Pharm Biomed Anal 2015; 113:72-96. [DOI: 10.1016/j.jpba.2015.03.002] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 02/28/2015] [Accepted: 03/03/2015] [Indexed: 11/22/2022]
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19
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Saylor RA, Reid EA, Lunte SM. Microchip electrophoresis with electrochemical detection for the determination of analytes in the dopamine metabolic pathway. Electrophoresis 2015; 36:1912-9. [PMID: 25958983 DOI: 10.1002/elps.201500150] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 04/10/2015] [Accepted: 04/14/2015] [Indexed: 12/23/2022]
Abstract
A method for the separation and detection of analytes in the dopamine metabolic pathway was developed using microchip electrophoresis with electrochemical detection. The microchip consisted of a 5 cm PDMS separation channel in a simple-t configuration. Analytes in the dopamine metabolic pathway were separated using a background electrolyte composed of 15 mM phosphate at pH 7.4, 15 mM SDS, and 2.5 mM boric acid. Two different microchip substrates using different electrode materials were compared for the analysis: a PDMS/PDMS device with a carbon fiber electrode and a PDMS/glass hybrid device with a pyrolyzed photoresist film carbon electrode. While the PDMS/PDMS device generated high separation efficiencies and good resolution, more reproducible migration times were obtained with the PDMS/glass hybrid device, making it a better choice for biological applications. Lastly, the optimized method was used to monitor l-DOPA metabolism in a rat brain slice.
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Affiliation(s)
- Rachel A Saylor
- Department of Chemistry, University of Kansas, Lawrence, KS, USA.,Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, KS, USA
| | - Erin A Reid
- Department of Chemistry, University of Kansas, Lawrence, KS, USA.,Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, KS, USA
| | - Susan M Lunte
- Department of Chemistry, University of Kansas, Lawrence, KS, USA.,Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, KS, USA.,Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS, USA
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20
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Saylor RA, Lunte SM. A review of microdialysis coupled to microchip electrophoresis for monitoring biological events. J Chromatogr A 2015; 1382:48-64. [PMID: 25637011 DOI: 10.1016/j.chroma.2014.12.086] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 12/23/2014] [Accepted: 12/26/2014] [Indexed: 12/30/2022]
Abstract
Microdialysis is a powerful sampling technique that enables monitoring of dynamic processes in vitro and in vivo. The combination of microdialysis with chromatographic or electrophoretic methods with selective detection yields a "separation-based sensor" capable of monitoring multiple analytes in near real time. For monitoring biological events, analysis of microdialysis samples often requires techniques that are fast (<1 min), have low volume requirements (nL-pL), and, ideally, can be employed on-line. Microchip electrophoresis fulfills these requirements and also permits the possibility of integrating sample preparation and manipulation with detection strategies directly on-chip. Microdialysis coupled to microchip electrophoresis has been employed for monitoring biological events in vivo and in vitro. This review discusses technical considerations for coupling microdialysis sampling and microchip electrophoresis, including various interface designs, and current applications in the field.
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Affiliation(s)
- Rachel A Saylor
- Department of Chemistry, University of Kansas, Lawrence, KS 66045, USA; Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, KS 66047, USA.
| | - Susan M Lunte
- Department of Chemistry, University of Kansas, Lawrence, KS 66045, USA; Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66047, USA; Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, KS 66047, USA.
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21
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Uthuppu B, Heiskanen A, Kofoed D, Aamand J, Jørgensen C, Dufva M, Jakobsen MH. Micro-flow-injection analysis (μFIA) immunoassay of herbicide residue 2,6-dichlorobenzamide – towards automated at-line monitoring using modular microfluidics. Analyst 2015; 140:1616-23. [DOI: 10.1039/c4an01576b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A prototype microfluidic immunosensor for detecting 2,6-dichlorobenzamide showing potential for at-line monitoring of ground water.
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Affiliation(s)
- Basil Uthuppu
- Department of Micro- and Nanotechnology
- Technical University of Denmark
- 2800 Kgs. Lyngby
- Denmark
| | - Arto Heiskanen
- Department of Micro- and Nanotechnology
- Technical University of Denmark
- 2800 Kgs. Lyngby
- Denmark
| | - Dan Kofoed
- Department of Micro- and Nanotechnology
- Technical University of Denmark
- 2800 Kgs. Lyngby
- Denmark
| | - Jens Aamand
- The Geological Survey of Denmark and Greenland (GEUS)
- 1350 Copenhagen
- Denmark
| | | | - Martin Dufva
- Department of Micro- and Nanotechnology
- Technical University of Denmark
- 2800 Kgs. Lyngby
- Denmark
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22
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Lucca BG, Lunte SM, Tomazelli Coltro WK, Ferreira VS. Separation of natural antioxidants using PDMS electrophoresis microchips coupled with amperometric detection and reverse polarity. Electrophoresis 2014; 35:3363-70. [PMID: 25224541 DOI: 10.1002/elps.201400359] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 08/27/2014] [Accepted: 08/28/2014] [Indexed: 12/12/2022]
Abstract
This report describes the use of PDMS ME coupled with amperometric detection for rapid separation of ascorbic, gallic , ferulic, p-coumaric acids using reverse polarity. ME devices were fabricated in PDMS by soft lithography and detection was accomplished using an integrated carbon fiber working electrode aligned in the end-channel configuration. Separation and detection parameters were investigated and the best conditions were obtained using a run buffer consisting of 5 mM phosphate buffer (pH 6.9) and a detection voltage of 1.0 V versus Ag/AgCl reference electrode. All compounds were separated within 70 s using gated injection mode with baseline resolution and separation efficiencies between 1200 and 9000 plates. Calibration curves exhibited good linearity and the LODs achieved ranged from 1.7 to 9.7 μM. The precision for migration time and peak height provided maximum values of 4% for the intrachip studies. Lastly, the analytical method was successfully applied for the analysis of ascorbic and gallic acids in commercial beverage samples. The results achieved using ME coupled with amperometric detection were in good agreement with the values provided by the supplier. Based on the data reported here, the proposed method shows suitability to be applied for the routine analysis of beverage samples.
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Affiliation(s)
- Bruno Gabriel Lucca
- Instituto de Química, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brazil
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Bubendorfer AJ, Ingham B, Kennedy JV, Arnold WM. Contamination of PDMS microchannels by lithographic molds. LAB ON A CHIP 2013; 13:4312-4316. [PMID: 24080639 DOI: 10.1039/c3lc50641j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
By use of synchrotron X-ray fluorescence and Rutherford backscattering spectrometry, we show the SU-8 soft lithographic process contaminates PDMS. Residues of the antimony containing photoinitiator are transferred from the master mold to the surface of PDMS, uncontrollably intensifying the surface potential, leading to electroosmotic flow variability in PDMS microfluidic devices.
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24
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Lima RS, Carneiro Leão PAG, Monteiro AM, de Oliveira Piazzetta MH, Gobbi AL, Mazo LH, Carrilho E. Glass/SU-8 microchip for electrokinetic applications. Electrophoresis 2013. [DOI: 10.1002/elps.201300167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | | | | | | | - Angelo Luiz Gobbi
- Laboratório Nacional de Nanotecnologia; Centro Nacional de Pesquisa em Energia e Materiais; Campinas; SP; Brazil
| | - Luiz Henrique Mazo
- Instituto de Química de São Carlos; Universidade de São Paulo; São Carlos; SP; Brazil
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25
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Scott DE, Grigsby R, Lunte SM. Microdialysis sampling coupled to microchip electrophoresis with integrated amperometric detection on an all-glass substrate. Chemphyschem 2013; 14:2288-94. [PMID: 23794474 PMCID: PMC4000424 DOI: 10.1002/cphc.201300449] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Indexed: 12/30/2022]
Abstract
The development of an all-glass separation-based sensor using microdialysis coupled to microchip electrophoresis with amperometric detection is described. The system includes a flow-gated interface to inject discrete sample plugs from the microdialysis perfusate into the microchip electrophoresis system. Electrochemical detection was accomplished with a platinum electrode in an in-channel configuration using a wireless electrically isolated potentiostat. To facilitate bonding around the in-channel electrode, a fabrication process was employed that produced a working and a reference electrode flush with the glass surface. Both normal and reversed polarity separations were performed with this sensor. The system was evaluated in vitro for the continuous monitoring of the production of hydrogen peroxide from the reaction of glucose oxidase with glucose. Microdialysis experiments were performed using a BASi loop probe with an overall lag time of approximately five minutes and a rise time of less than 60 seconds.
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Affiliation(s)
- David E. Scott
- Department of Chemistry, University of Kansas
- Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas
| | - Ryan Grigsby
- Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas
| | - Susan M. Lunte
- Department of Chemistry, University of Kansas
- Department of Pharmaceutical Chemistry, University of Kansas
- Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas
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26
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Gabriel EFM, do Lago CL, Gobbi ÂL, Carrilho E, Coltro WKT. Characterization of microchip electrophoresis devices fabricated by direct-printing process with colored toner. Electrophoresis 2013; 34:2169-76. [DOI: 10.1002/elps.201300024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 03/04/2013] [Accepted: 04/02/2013] [Indexed: 11/12/2022]
Affiliation(s)
| | | | - Ângelo L. Gobbi
- Laboratório de Microfabricação; Laboratório Nacional de Nanotecnologia; Campinas, SP; Brazil
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27
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da Silva ER, Segato TP, Coltro WKT, Lima RS, Carrilho E, Mazo LH. Determination of glyphosate and AMPA on polyester-toner electrophoresis microchip with contactless conductivity detection. Electrophoresis 2013; 34:2107-11. [PMID: 23595638 DOI: 10.1002/elps.201200588] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 03/10/2013] [Accepted: 03/12/2013] [Indexed: 11/07/2022]
Abstract
This paper reports a method for rapid, simple, direct, and reproducible determination of glyphosate and its major metabolite aminomethylphosphonic acid (AMPA). The platform described herein uses polyester-toner microchips incorporating capacitively coupled contactless conductivity detection and electrophoresis separation of the analytes. The polyester-toner microchip presented 150 μm-wide and 12 μm-deep microchannels, with injection and separation lengths of 10 and 40 mm long, respectively. The best results were obtained with 320 kHz frequency, 4.5 Vpp excitation voltage, 80 mmol/L CHES/Tris buffer at pH 8.8, injection in -1.0 kV for 7 s, and separation in -1.5 kV. RSD values related to the peak areas for glyphosate and AMPA were 1.5 and 3.3% and 10.1 and 8.6% for intra- and interchip assays, respectively. The detection limits were 45.1 and 70.5 μmol/L, respectively, without any attempt of preconcentration of the analytes. Finally, the method was applied to river water samples in which glyphosate and AMPA (1.0 mmol/L each) were added. The recovery results were 87.4 and 83.7% for glyphosate and AMPA, respectively. The recovery percentages and LOD values obtained here were similar to others reported in the literature.
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Affiliation(s)
- Eduardo R da Silva
- Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil
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28
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Ouyang Y, Wang S, Li J, Riehl PS, Begley M, Landers JP. Rapid patterning of 'tunable' hydrophobic valves on disposable microchips by laser printer lithography. LAB ON A CHIP 2013; 13:1762-1771. [PMID: 23478812 DOI: 10.1039/c3lc41275j] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We recently defined a method for fabricating multilayer microdevices using poly(ethylene terephthalate) transparency film and printer toner, and showed these could be successfully applied to DNA extraction and amplification (Duarte et al., Anal. Chem. 2011, 83, 5182-5189). Here, we advance the functionality of these microdevices with flow control enabled by hydrophobic valves patterned using laser printer lithography. Laser printer patterning of toner within the microchannel induces a dramatic change in surface hydrophobicity (change in contact angle of DI water from 51° to 111°) with good reproducibility. Moreover, the hydrophobicity of the surface can be controlled by altering the density of the patterned toner via varying the gray-scale setting on the laser printer, which consequently tunes the valve's burst pressure. Toner density provided a larger burst pressure bandwidth (158 ± 18 Pa to 573 ± 16 Pa) than could be achieved by varying channel geometry (492 ± 18 Pa to 573 ± 16 Pa). Finally, we used a series of tuned toner valves (with varied gray-scale) for passive valve-based fluidic transfer in a predictable manner through the architecture of a rotating PeT microdevice. While an elementary demonstration, this presents the possibility for simplistic and cost-effective microdevices with valved fluid flow control to be fabricated using nothing more than a laser printer, a laser cutter and a laminator.
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Affiliation(s)
- Yiwen Ouyang
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA
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29
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On-chip immunoassay of a cardiac biomarker in serum using a polyester-toner microchip. Talanta 2013; 109:20-5. [DOI: 10.1016/j.talanta.2013.03.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 03/09/2013] [Accepted: 03/12/2013] [Indexed: 11/21/2022]
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30
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Oliveira KA, Rodrigues de Oliveira C, Antonelli da Silveira L, Tomazelli Coltro WK. Laser-printing of toner-based 96-microzone plates for immunoassays. Analyst 2013; 138:1114-21. [DOI: 10.1039/c2an36532d] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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31
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Fernández-la-Villa A, Sánchez-Barragán D, Pozo-Ayuso DF, Castaño-Álvarez M. Smart portable electrophoresis instrument based on multipurpose microfluidic chips with electrochemical detection. Electrophoresis 2012; 33:2733-42. [PMID: 22965719 DOI: 10.1002/elps.201200236] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A second generation of a battery-powered portable electrophoresis instrument for the use of ME with electrochemical detection was developed. As the first-generation, the main unit of the instrument (150 mm × 165 mm × 95 mm) consists of four-outputs high-voltage power supply (HVPS) with maximum voltage of 3 KV and acquisition system (bipotentiostat) containing 2-channels for dual electrochemical detection. A new reusable microfluidic platform was designed in order to incorporate the microchips with the portable instrument. In this case, the platform is integrated to the main unit of the instrument so that it is not necessary to have any external cable for the interconnection of both parts, making the use of the complete system easier. The new platform contains all the electrical connections for the HVPS and bipotentiostat, as well as fluidic ports for driving the solutions. The microfluidic electrophoresis instrument is controlled by means of a user-friendly interface from a computer. The possibility of wireless connection (Bluetooth®) allows the use of the instrument without any external cable improving the portability. Therefore, the second generation brings a more compact and integrated electrophoresis instrument for "in situ" applications using microfluidic chips in an easy way. The performance of the electrophoresis system was initially evaluated using single- and dual-channel SU-8/Pyrex microchips with different models of integrated electrodes including microelectrodes and interdigitated arrays. The method was tested in different analytical applications such as separation of neurotransmitters, chlorophenols, purine derivatives, vitamins, polyphenolic acids, and flavones.
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32
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de Souza FR, Alves GL, Coltro WKT. Capillary-Driven Toner-Based Microfluidic Devices for Clinical Diagnostics with Colorimetric Detection. Anal Chem 2012; 84:9002-7. [DOI: 10.1021/ac302506k] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Fabrício Ribeiro de Souza
- Instituto de Química, Universidade Federal de Goiás, Campus Samambaia,
P.O. Box 131, 74001-970, Goiânia, GO, Brazil
| | - Guilherme Liberato Alves
- Instituto de Química, Universidade Federal de Goiás, Campus Samambaia,
P.O. Box 131, 74001-970, Goiânia, GO, Brazil
| | - Wendell Karlos Tomazelli Coltro
- Instituto de Química, Universidade Federal de Goiás, Campus Samambaia,
P.O. Box 131, 74001-970, Goiânia, GO, Brazil
- Instituto Nacional de Ciência e Tecnologia de Bioanalítica, 13083-970, Campinas, SP, Brazil
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33
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Polyester-toner electrophoresis microchips with improved analytical performance and extended lifetime. Electrophoresis 2012; 33:2660-7. [DOI: 10.1002/elps.201200009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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34
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Linz TH, Snyder CM, Lunte SM. Optimization of the separation of NDA-derivatized methylarginines by capillary and microchip electrophoresis. ACTA ACUST UNITED AC 2012; 17:24-31. [PMID: 22357605 DOI: 10.1177/2211068211424551] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The methylated arginines (MAs) monomethylarginine (MMA), asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA) have been shown to be independent predictors of cardiovascular disease. This article describes progress regarding the development of an analytical method capable of rapidly analyzing MAs using capillary electrophoresis (CE) and microchip electrophoresis (MCE) with laser-induced fluorescence (LIF) detection. Several parameters including buffer composition and separation voltage were optimized to achieve an ideal separation. The analytes of interest were derivatized with naphthalene-2,3-dicarboxaldehyde (NDA) to produce fluorescent 1-cyanobenz[f]isoindole (CBI) derivatives and then subjected to CE analysis. Baseline resolution of SDMA, ADMA, MMA, and arginine was achieved in less than 8 min. The limits of detection for SDMA, ADMA, MMA, and arginine were determined to be 15, 20, 25, and 5 nM, respectively, which are well below the expected plasma concentrations. The CE separation method was then transferred to a glass MCE device with LIF detection. MAs were baseline resolved in 3 min on-chip using a 14 cm separation channel with detection limits of approximately 10 nM for each species. To the best of the authors' knowledge, this is the first report of the separation of MAs by MCE.
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Affiliation(s)
- Thomas H Linz
- Department of Chemistry, University of Kansas, Lawrence, KS, USA
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35
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Duarte GRM, Coltro WKT, Borba JC, Price CW, Landers JP, Carrilho E. Disposable polyester-toner electrophoresis microchips for DNA analysis. Analyst 2012; 137:2692-8. [PMID: 22545263 DOI: 10.1039/c2an16220b] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Microchip electrophoresis has become a powerful tool for DNA separation, offering all of the advantages typically associated with miniaturized techniques: high speed, high resolution, ease of automation, and great versatility for both routine and research applications. Various substrate materials have been used to produce microchips for DNA separations, including conventional (glass, silicon, and quartz) and alternative (polymers) platforms. In this study, we perform DNA separation in a simple and low-cost polyester-toner (PeT)-based electrophoresis microchip. PeT devices were fabricated by a direct-printing process using a 600 dpi-resolution laser printer. DNA separations were performed on PeT chip with channels filled with polymer solutions (0.5% m/v hydroxyethylcellulose or hydroxypropylcellulose) at electric fields ranging from 100 to 300 V cm(-1). Separation of DNA fragments between 100 and 1000 bp, with good correlation of the size of DNA fragments and mobility, was achieved in this system. Although the mobility increased with increasing electric field, separations showed the same profile regardless of the electric field. The system provided good separation efficiency (215,000 plates per m for the 500 bp fragment) and the separation was completed in 4 min for 1000 bp fragment ladder. The cost of a given chip is approximately $0.15 and it takes less than 10 minutes to prepare a single device.
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Affiliation(s)
- Gabriela R M Duarte
- Instituto de Química de São Carlos, Universidade de São Paulo, Grupo de Bioanalítica, Microfabricação e Separações, Brazil
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36
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Zhuang H, Song B, Staedler T, Jiang X. Microcontact printing of monodiamond nanoparticles: an effective route to patterned diamond structure fabrication. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:11981-11989. [PMID: 21866927 DOI: 10.1021/la2024428] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
By combining microcontact printing with a nanodiamond seeding technique, a precise micrometer-sized chemical vapor deposition (CVD) diamond pattern have been obtained. On the basis of the guidance of basic theoretical calculations, monodisperse detonation nanodiamonds (DNDs) were chosen as an "ink" material and oxidized poly(dimethylsiloxane) (PDMS) was selected to serve as a stamp because it features a higher interaction energy with the DNDs compared to that of the original PDMS. The adsorption kinetics shows an approximately exponential law with a maximum surface DND density of 3.4 × 10(10) cm(-2) after 20 min. To achieve a high transfer ratio of DNDs from the PDMS stamp to a silicon surface, a thin layer of poly(methyl methacrylate) (PMMA) was spin coated onto the substrates. A microwave plasma chemical vapor deposition system was used to synthesize the CVD diamond on the seeded substrate areas. Precise diamond patterns with a low expansion ratio (3.6%) were successfully prepared after 1.5 h of deposition. Further increases in the deposition time typically lead to a high expansion rate (∼0.8 μm/h). The general pattern shape, however, did not show any significant change. Compared with conventional diamond pattern deposition methods, the technique described here offers the advantages of being simple, inexpensive, damage-free, and highly compatible, rendering it attractive for a broad variety of industrial applications.
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Affiliation(s)
- Hao Zhuang
- Institute of Materials Engineering, University of Siegen, 57076 Siegen, Germany
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37
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A continuous DC-insulator dielectrophoretic sorter of microparticles. J Chromatogr A 2011; 1218:1780-9. [DOI: 10.1016/j.chroma.2011.01.082] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 01/21/2011] [Accepted: 01/27/2011] [Indexed: 11/22/2022]
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38
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Tomazelli Coltro WK, Fracassi da Silva JA, Carrilho E. Rapid prototyping of polymeric electrophoresis microchips with integrated electrodes for contactless conductivity detection. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2011; 3:168-172. [PMID: 32938126 DOI: 10.1039/c0ay00486c] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
A simple and easy approach to produce polymeric microchips with integrated copper electrodes for capacitively coupled contactless conductivity detection (C4D) is described. Copper electrodes were fabricated using a printed circuit board (PCB) as an inexpensive thin-layer of metal. The electrode layout was first drawn and laser printed on a wax paper sheet. The toner layer deposited on the paper sheet was thermally transferred to the PCB surface working as a mask for wet chemical etching of the copper layer. After the etching step, the toner was removed with an acetonitrile-dampened cotton. A poly(ethylene terephthalate) (PET) film coated with a thin thermo-sensitive adhesive layer was used to laminate the PCB plate providing an insulator layer of the electrodes to perform C4D measurements. Electrophoresis microchannels were fabricated in poly(dimethylsiloxane) (PDMS) by soft lithography and reversibly sealed against the PET film. These hybrid PDMS/PET chips exhibited a stable electroosmotic mobility of 4.25 ± 0.04 × 10-4 V cm-2 s-1, at pH 6.1, over fifty runs. Efficiencies ranging from 1127 to 1690 theoretical plates were obtained for inorganic cations.
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Affiliation(s)
- Wendell Karlos Tomazelli Coltro
- Instituto de Química, Universidade Federal de Goiás, Campus Samambaia, 74001-970, Goiânia, GO, Brazil.
- Instituto Nacional de Ciência e Tecnologia de Bioanalítica, Campinas, SP, Brazil
| | - Josà Alberto Fracassi da Silva
- Instituto Nacional de Ciência e Tecnologia de Bioanalítica, Campinas, SP, Brazil
- Instituto de Química, Universidade Estadual de Campinas, 13083-970, Campinas, SP, Brazil.
| | - Emanuel Carrilho
- Instituto Nacional de Ciência e Tecnologia de Bioanalítica, Campinas, SP, Brazil
- Instituto de Química de São Carlos, Universidade de São Paulo, 13566-970, São Carlos, SP, Brazil.
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Segato TP, Coltro WKT, de Jesus Almeida AL, de Oliveira Piazetta MH, Gobbi AL, Mazo LH, Carrilho E. A rapid and reliable bonding process for microchip electrophoresis fabricated in glass substrates. Electrophoresis 2010; 31:2526-33. [DOI: 10.1002/elps.201000099] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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40
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Coltro WKT, de Jesus DP, da Silva JAF, do Lago CL, Carrilho E. Toner and paper-based fabrication techniques for microfluidic applications. Electrophoresis 2010; 31:2487-98. [DOI: 10.1002/elps.201000063] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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41
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Thomas MS, Millare B, Clift JM, Bao D, Hong C, Vullev VI. Print-and-peel fabrication for microfluidics: what's in it for biomedical applications? Ann Biomed Eng 2009; 38:21-32. [PMID: 19898937 PMCID: PMC2803264 DOI: 10.1007/s10439-009-9831-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2009] [Accepted: 10/23/2009] [Indexed: 01/09/2023]
Abstract
This article reviews the development and the advances of print-and-peel (PAP) microfabrication. PAP techniques provide means for facile and expedient prototyping of microfluidic devices. Therefore, PAP has the potential for broadening the microfluidics technology by bringing it to researchers who lack regular or any accesses to specialized fabrication facilities and equipment. Microfluidics have, indeed, proven to be an indispensable toolkit for biological and biomedical research and development. Through accessibility to such methodologies for relatively fast and easy prototyping, PAP has the potential to considerably accelerate the impacts of microfluidics on the biological sciences and engineering. In summary, PAP encompasses: (1) direct printing of the masters for casting polymer device components; and (2) adding three-dimensional elements onto the masters for single-molding-step formation of channels and cavities within the bulk of the polymer slabs. Comparative discussions of the different PAP techniques, along with the current challenges and approaches for addressing them, outline the perspectives for PAP and how it can be readily adopted by a broad range of scientists and engineers.
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Affiliation(s)
- Marlon S Thomas
- Department of Bioengineering, University of California, Riverside, CA 92521, USA
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42
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Castaño-Álvarez M, Fernández-la-Villa A, Pozo-Ayuso DF, Fernández-Abedul MT, Costa-García A. Multiple-point electrochemical detection for a dual-channel hybrid PDMS-glass microchip electrophoresis device. Electrophoresis 2009; 30:3372-80. [DOI: 10.1002/elps.200900291] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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