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Couceiro P, Alonso-Chamarro J. Fluorescence Imaging Characterization of the Separation Process in a Monolithic Microfluidic Free-Flow Electrophoresis Device Fabricated Using Low-Temperature Co-Fired Ceramics. MICROMACHINES 2022; 13:mi13071023. [PMID: 35888840 PMCID: PMC9324176 DOI: 10.3390/mi13071023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/22/2022] [Accepted: 06/24/2022] [Indexed: 11/26/2022]
Abstract
A monolithic microfluidic free-flow electrophoresis device, fabricated using low-temperature co-fired ceramic technology, is presented. The device integrates gold electrodes and a 20 µm thick transparent ceramic optical window, suitable for fluorescence imaging, into a multilevel microfluidic chamber design. The microfluidic chamber consists of a 60 µm deep separation chamber and two, 50 µm deep electrode chambers separated by 10 µm deep side channel arrays. Fluorescence imaging was used for in-chip, spatial-temporal characterization of local pH variations in separation conditions as well as to characterize the separation process. The device allowed baseline resolution separation of a sample mixture of Fluorescein, Rhodamine 6G, and 4-Methylumbelliferone at pH 7.0, in only 6 s, using 378 V.s/cm. The results demonstrate the possibility of studying a chemical process using fluorescence imaging within the traditional fields of low-temperature co-fired ceramics technology, such as high-electrical-field applications, while using a simple fabrication procedure suitable for low-cost mass production.
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Couceiro P, Alonso-Chamarro J. Microfabrication of Monolithic Microfluidic Platforms Using Low Temperature Co-Fired Ceramics Suitable for Fluorescence Imaging. Anal Chem 2017; 89:9147-9153. [DOI: 10.1021/acs.analchem.7b01889] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Pedro Couceiro
- Sensors and Biosensors Group,
Department of Chemistry, Autonomous University of Barcelona, Edifici Cn, 08193 Bellaterra, Catalonia Spain
| | - Julián Alonso-Chamarro
- Sensors and Biosensors Group,
Department of Chemistry, Autonomous University of Barcelona, Edifici Cn, 08193 Bellaterra, Catalonia Spain
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Lima RS, Piazzetta MHO, Gobbi AL, Segato TP, Cabral MF, Machado SAS, Carrilho E. Highly sensitive contactless conductivity microchips based on concentric electrodes for flow analysis. Chem Commun (Camb) 2013; 49:11382-4. [DOI: 10.1039/c3cc45797d] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Mark JJP, Scholz R, Matysik FM. Electrochemical methods in conjunction with capillary and microchip electrophoresis. J Chromatogr A 2012; 1267:45-64. [PMID: 22824222 DOI: 10.1016/j.chroma.2012.07.009] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 07/01/2012] [Accepted: 07/06/2012] [Indexed: 02/06/2023]
Abstract
Electromigrative techniques such as capillary and microchip electrophoresis (CE and MCE) are inherently associated with various electrochemical phenomena. The electrolytic processes occurring in the buffer reservoirs have to be considered for a proper design of miniaturized electrophoretic systems and a suitable selection of buffer composition. In addition, the control of the electroosmotic flow plays a crucial role for the optimization of CE/MCE separations. Electroanalytical methods have significant importance in the field of detection in conjunction with CE/MCE. At present, amperometric detection and contactless conductivity detection are the predominating electrochemical detection methods for CE/MCE. This paper reviews the most recent trends in the field of electrochemical detection coupled to CE/MCE. The emphasis is on methodical developments and new applications that have been published over the past five years. A rather new way for the implementation of electrochemical methods into CE systems is the concept of electrochemically assisted injection which involves the electrochemical conversions of analytes during the injection step. This approach is particularly attractive in hyphenation to mass spectrometry (MS) as it widens the range of CE-MS applications. An overview of recent developments of electrochemically assisted injection coupled to CE is presented.
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Affiliation(s)
- Jonas J P Mark
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, Regensburg, Germany
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Lima RS, Segato TP, Gobbi AL, Coltro WKT, Carrilho E. Doping of a dielectric layer as a new alternative for increasing sensitivity of the contactless conductivity detection in microchips. LAB ON A CHIP 2011; 11:4148-4151. [PMID: 22045405 DOI: 10.1039/c1lc20757a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This communication describes a new procedure to increase the sensitivity of C(4)D in PDMS/glass microchips. The method consists in doping the insulating layer (PDMS) over the electrodes with nanoparticles of TiO(2), increasing thus its dielectric constant. The experimental protocol is simple, inexpensive, and fast.
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Affiliation(s)
- Renato Sousa Lima
- Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos, Brazil
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Kubáň P, Timerbaev AR. CE of inorganic species - A review of methodological advancements over 2009-2010. Electrophoresis 2011; 33:196-210. [DOI: 10.1002/elps.201100357] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Revised: 07/30/2011] [Accepted: 07/30/2011] [Indexed: 01/13/2023]
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Zhao J, Chen Z, Li X, Pan J. A novel microchip based on indium tin oxide coated glass for contactless conductivity detection. Talanta 2011; 85:2614-9. [PMID: 21962691 DOI: 10.1016/j.talanta.2011.08.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 08/11/2011] [Accepted: 08/13/2011] [Indexed: 10/17/2022]
Abstract
A microfluidic chip manufactured from glass substrate and indium tin oxide (ITO) coated glass use for contactless conductivity detection was developed. The detecting electrodes were fabricated by screen-printing and chemical etching methods using an ITO-coated glass wafer. Then, the glass substrate containing separation channels was bonded with the bare side of the processed ITO-coated glass, thus producing an electrophoresis chip integrated with contactless conductivity detector. The prepared microchip displayed considerable stability and reproducibility. Sensitive response was obtained at optimal conditions (including the gap between electrodes, excitation frequency, and excitation voltage). The feasibility of this microfluidic device was examined by detection of inorganic ions, and further demonstrated by the quantification of aminopyrine and caffeine in a compound pharmaceutical. The two ingredients can be completely separated within 1 min. The detection limits were 8 μg mL(-1) and 3 μg mL(-1), respectively; with the correlation coefficient of 0.996-0.998 in the linear range from 10 μg mL(-1) to 800 μg mL(-1). The results have showed that the present method is sensitive, reliable and fast.
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Affiliation(s)
- Jing Zhao
- Institute of Analytical Instruments, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, Guangdong 510006, PR China
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Kubáň P, Hauser PC. Capacitively coupled contactless conductivity detection for microseparation techniques - recent developments. Electrophoresis 2010; 32:30-42. [DOI: 10.1002/elps.201000354] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Revised: 08/12/2010] [Accepted: 08/13/2010] [Indexed: 11/09/2022]
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Felhofer JL, Blanes L, Garcia CD. Recent developments in instrumentation for capillary electrophoresis and microchip-capillary electrophoresis. Electrophoresis 2010; 31:2469-86. [PMID: 20665910 PMCID: PMC2928674 DOI: 10.1002/elps.201000203] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Over the last years, there has been an explosion in the number of developments and applications of CE and microchip-CE. In part, this growth has been the direct consequence of recent developments in instrumentation associated with CE. This review, which is focused on the contributions published in the last 5 years, is intended to complement the articles presented in this special issue dedicated to instrumentation and to provide an overview of the general trends and some of the most remarkable developments published in the areas of high-voltage power supplies, detectors, auxiliary components, and compact systems. It also includes a few examples of alternative uses of and modifications to traditional CE instruments.
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Affiliation(s)
- Jessica L. Felhofer
- Department of Chemistry, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, United States of America
| | - Lucas Blanes
- Centre for Forensic Science, University of Technology, Sydney, PO Box 123, Broadway, NSW 2007, Australia
| | - Carlos D. Garcia
- Department of Chemistry, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, United States of America
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Fercher G, Haller A, Smetana W, Vellekoop MJ. End-to-End Differential Contactless Conductivity Sensor for Microchip Capillary Electrophoresis. Anal Chem 2010; 82:3270-5. [DOI: 10.1021/ac100041p] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Georg Fercher
- Institute of Sensor and Actuator Systems, Vienna University of Technology, Vienna, Austria, and IMA GmbH, Wiener Neustadt, Austria
| | - Anna Haller
- Institute of Sensor and Actuator Systems, Vienna University of Technology, Vienna, Austria, and IMA GmbH, Wiener Neustadt, Austria
| | - Walter Smetana
- Institute of Sensor and Actuator Systems, Vienna University of Technology, Vienna, Austria, and IMA GmbH, Wiener Neustadt, Austria
| | - Michael J. Vellekoop
- Institute of Sensor and Actuator Systems, Vienna University of Technology, Vienna, Austria, and IMA GmbH, Wiener Neustadt, Austria
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Fercher G, Haller A, Smetana W, Vellekoop MJ. Ceramic capillary electrophoresis chip for the measurement of inorganic ions in water samples. Analyst 2010; 135:965-70. [PMID: 20419244 DOI: 10.1039/b922501c] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present a microchip capillary electrophoresis (CE) device build-up in low temperature co-fired ceramics (LTCC) multilayer technology for the analysis of major inorganic ions in water samples in less than 80 s. Contactless conductivity measurement is employed as a robust alternative to direct-contact conductivity detection schemes. The measurement electrodes are placed in a planar way at the top side of the CE chip and are realized by screen printing. Laser-cutting of channel and double-T injector structures is used to minimize irregularities and wall defects, elevating plate numbers per meter up to values of 110,000. Lowest limit of detection is 6 microM. The cost efficient LTCC module is attractive particularly for portable instruments in environmental applications because of its chemical inertness, hermeticity and easy three-dimensional integration capabilities of fluidic, electrical and mechanical components.
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Affiliation(s)
- Georg Fercher
- Integrated Microsystems Austria GmbH, Viktor Kaplan Strasse 2/1, 2700, Wiener Neustadt, Austria.
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