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Selemani MA, Martin RS. Use of 3D printing to integrate microchip electrophoresis with amperometric detection. Anal Bioanal Chem 2024:10.1007/s00216-024-05260-6. [PMID: 38581532 DOI: 10.1007/s00216-024-05260-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/08/2024] [Accepted: 03/15/2024] [Indexed: 04/08/2024]
Abstract
This paper describes the use of PolyJet 3D printing to fabricate microchip electrophoresis devices with integrated microwire electrodes for amperometric detection. The fabrication process involves 3D printing of two separate pieces, a channel layer and an electrode layer. The channel layer is created by 3D printing on a pre-fabricated mold with a T-intersection. For the electrode layer, a stencil design is printed directly on the printing tray and covered with a piece of transparent glass. Microwire electrodes are adhered over the glass piece (guided by underlaying stencil) and a CAD design of the electrode layer is then printed on top of the microwire electrode. After delamination from the glass after printing, the microwire is embedded in the printed piece, with the stencil design ensuring that alignment and positioning of the electrode is reproducible for each print. After a thermal bonding step between the channel layer and electrode layer, a complete electrophoresis device with integrated microelectrodes for amperometric detection results. It is shown that this approach enables different microwire electrodes (gold or platinum) and sizes (100 or 50 µm) to be integrated in an end-channel configuration with no gap between the electrode and the separation channel. These devices were used to separate a mixture of catecholamines and the effect of separation voltage on the potential voltage applied on the working electrode was also investigated. In addition, the effect of electrode size on the number of theoretical plates and limit of detection was studied. Finally, a device that contains different channel heights and a detection electrode was 3D-printed to integrate continuous flow sampling with microchip electrophoresis and amperometric detection.
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Affiliation(s)
- Major A Selemani
- Department of Chemistry, Saint Louis University, Saint Louis, MO, USA
| | - R Scott Martin
- Department of Chemistry, Saint Louis University, Saint Louis, MO, USA.
- Center for Additive Manufacturing, Saint Louis University, Saint Louis, MO, USA.
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Farahinia A, Zhang W, Badea I. Recent Developments in Inertial and Centrifugal Microfluidic Systems along with the Involved Forces for Cancer Cell Separation: A Review. SENSORS (BASEL, SWITZERLAND) 2023; 23:s23115300. [PMID: 37300027 DOI: 10.3390/s23115300] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 04/23/2023] [Accepted: 05/17/2023] [Indexed: 06/12/2023]
Abstract
The treatment of cancers is a significant challenge in the healthcare context today. Spreading circulating tumor cells (CTCs) throughout the body will eventually lead to cancer metastasis and produce new tumors near the healthy tissues. Therefore, separating these invading cells and extracting cues from them is extremely important for determining the rate of cancer progression inside the body and for the development of individualized treatments, especially at the beginning of the metastasis process. The continuous and fast separation of CTCs has recently been achieved using numerous separation techniques, some of which involve multiple high-level operational protocols. Although a simple blood test can detect the presence of CTCs in the blood circulation system, the detection is still restricted due to the scarcity and heterogeneity of CTCs. The development of more reliable and effective techniques is thus highly desired. The technology of microfluidic devices is promising among many other bio-chemical and bio-physical technologies. This paper reviews recent developments in the two types of microfluidic devices, which are based on the size and/or density of cells, for separating cancer cells. The goal of this review is to identify knowledge or technology gaps and to suggest future works.
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Affiliation(s)
- Alireza Farahinia
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9, Canada
| | - Wenjun Zhang
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9, Canada
| | - Ildiko Badea
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
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Subramanian S, Huiszoon RC, Chu S, Bentley WE, Ghodssi R. Microsystems for biofilm characterization and sensing - A review. Biofilm 2020; 2:100015. [PMID: 33447801 PMCID: PMC7798443 DOI: 10.1016/j.bioflm.2019.100015] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/11/2019] [Accepted: 11/26/2019] [Indexed: 11/30/2022] Open
Abstract
Biofilms are the primary cause of clinical bacterial infections and are impervious to typical amounts of antibiotics, necessitating very high doses for elimination. Therefore, it is imperative to have suitable methods for characterization to develop novel methods of treatment that can complement or replace existing approaches using significantly lower doses of antibiotics. This review presents some of the current developments in microsystems for characterization and sensing of bacterial biofilms. Initially, we review current standards for studying biofilms that are based on invasive and destructive end-point biofilm characterization. Additionally, biofilm formation and growth is extremely sensitive to various growth and environmental parameters that cause large variability in biofilms between repeated experiments, making it very difficult to compare experimental repeats and characterize the temporal characteristics of these organisms. To address these challenges, recent developments in the field have moved toward systems and miniature devices that can aid in the non-invasive characterization of bacterial biofilms. Our review focuses on several types of microsystems for biofilm evaluation including optical, electrochemical, and mechanical systems. This review will show how these devices can lead to better understanding of the physiology and function of these communities of bacteria, which can eventually lead to the development of novel treatments that do not rely on high-dosage antibiotics.
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Affiliation(s)
- Sowmya Subramanian
- MEMS Sensors and Actuators Laboratory, University of Maryland, College Park, MD, USA
- Department of Electrical and Computer Engineering, University of Maryland, College Park, MD, USA
- Institute for Systems Research, University of Maryland, College Park, MD, USA
| | - Ryan C. Huiszoon
- MEMS Sensors and Actuators Laboratory, University of Maryland, College Park, MD, USA
- Institute for Systems Research, University of Maryland, College Park, MD, USA
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
- Robert E. Fischell Institute for Biomedical Devices, University of Maryland, College Park, MD, USA
| | - Sangwook Chu
- MEMS Sensors and Actuators Laboratory, University of Maryland, College Park, MD, USA
- Institute for Systems Research, University of Maryland, College Park, MD, USA
- Robert E. Fischell Institute for Biomedical Devices, University of Maryland, College Park, MD, USA
| | - William E. Bentley
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
- Robert E. Fischell Institute for Biomedical Devices, University of Maryland, College Park, MD, USA
| | - Reza Ghodssi
- MEMS Sensors and Actuators Laboratory, University of Maryland, College Park, MD, USA
- Department of Electrical and Computer Engineering, University of Maryland, College Park, MD, USA
- Institute for Systems Research, University of Maryland, College Park, MD, USA
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
- Robert E. Fischell Institute for Biomedical Devices, University of Maryland, College Park, MD, USA
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Hao Y, Bao Y, Huang X, Hu Y, Xiong B. On-line pre-treatment, separation, and nanoelectrospray mass spectrometric determinations for pesticide metabolites and peptides based on a modular microfluidic platform. RSC Adv 2018; 8:39811-39817. [PMID: 35558234 PMCID: PMC9091297 DOI: 10.1039/c8ra08276f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Accepted: 11/15/2018] [Indexed: 12/12/2022] Open
Abstract
In order to address time-consuming sample pre-treatment and separation prior to mass spectrometry (MS) identifications, highly integrated chips were developed, but damage to any functional unit in these chips would result in complete replacement. Herein, we propose a modular microfluidic platform comprising pre-treatment, liquid chromatography (LC) separation and nanoelectrospray ionization (nESI) chips for on-line enrichment, separation and nESI MS detection of pesticide metabolites and peptides. The pre-treatment chip is applicable in enriching pyridalyl and its metabolites, and it achieves optimal desalination efficiency, 98.5%, for polymerase chain reaction products. Additionally, the LC separation chip was fully characterised, and it demonstrated satisfactory separation efficiency, quantification ability and pressure durability. Finally, the modular microfluidic platform was used to identify the peptides in trypsin-digested casein. Four additional peptides were identified, indicating an improvement in detection ability compared with using off-line zip tips coupled with MS investigations. Because the proposed modular platform can significantly reduce manual work, it would be a potential tool to achieve high throughput and automatic MS identifications with low sample consumptions. A microfluidic platform, composed of enrichment, separation and nanoelectrospray ionization modulations was developed to on-line-investigate pesticide metabolites and peptides.![]()
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Affiliation(s)
- Yinyin Hao
- School of Mathematics and Statistics
- Wuhan University
- Wuhan
- China
- Key Laboratory of Pesticides & Chemical Biology
| | - Yajing Bao
- Key Laboratory of Pesticides & Chemical Biology
- Ministry of Education
- Institute of Public Health and Molecular Medicine Analysis
- College of Chemistry
- Central China Normal University
| | - Xueying Huang
- Key Laboratory of Pesticides & Chemical Biology
- Ministry of Education
- Institute of Public Health and Molecular Medicine Analysis
- College of Chemistry
- Central China Normal University
| | - Yijun Hu
- School of Mathematics and Statistics
- Wuhan University
- Wuhan
- China
| | - Bo Xiong
- Key Laboratory of Pesticides & Chemical Biology
- Ministry of Education
- Institute of Public Health and Molecular Medicine Analysis
- College of Chemistry
- Central China Normal University
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5
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Selmi M, Gazzah MH, Belmabrouk H. Numerical Study of the Electrothermal Effect on the Kinetic Reaction of Immunoassays for a Microfluidic Biosensor. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:13305-13312. [PMID: 27993020 DOI: 10.1021/acs.langmuir.6b02637] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
In this work, we simulate the binding reaction of C-reactive protein in a microchannel of a biosensor. A problem that arises in this device concerns the transport of the analyte toward the reaction surface of the biosensor, which is of a very small dimension. The limitation of mass transport causes the formation of a diffusion boundary layer and restrains the whole kinetic reaction. To enhance the performance of the biosensor by improving the transport, an applied AC electric field and flow confinement are used to stir the flow field. The numerical simulation of these mechanisms on the binding reaction is performed using the finite element method. Swirling patterns are generated in the fluid. They enhance the transport of the analyte and confine it near the reaction surface. The location of the electrode pair on the walls of the microchannel for the design of the biosensor has been studied to find out the effects of varying geometric configurations on the binding efficiency. The best performances of the biosensor are obtained when the electrodes are placed on the same wall of the microchannel as the reaction surface. For the best case, under the effect of the applied electric field alone, the enhancement factors raise up to 2.46 and 2.10 for the association and dissociation phases, respectively. By contrast, under the effect of the electric field with flow confinement, the enhancement factors for the association and the dissociation phases jump to 3.43 and 2.97, respectively, for 30:1 flow confinement (ratio of confining to sample flow).
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Affiliation(s)
- Marwa Selmi
- Laboratory of Electronics and Microelectronics, Faculty of Science of Monastir, University of Monastir , Environment Boulevard, Monastir 5019, Tunisia
- Department of Radiological Sciences and Medical Imaging, College of Applied Medical Sciences, Majmaah University , Al Majma'ah 11952, Saudi Arabia
| | - Mohamed Hichem Gazzah
- Laboratory of Electronics and Microelectronics, Faculty of Science of Monastir, University of Monastir , Environment Boulevard, Monastir 5019, Tunisia
| | - Hafedh Belmabrouk
- Laboratory of Electronics and Microelectronics, Faculty of Science of Monastir, University of Monastir , Environment Boulevard, Monastir 5019, Tunisia
- Department of Physics, College of Science AlZulfi, Majmaah University , Al Zulfi 11932, Saudi Arabia
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Guzman NA, Guzman DE. An emerging micro-scale immuno-analytical diagnostic tool to see the unseen. Holding promise for precision medicine and P4 medicine. J Chromatogr B Analyt Technol Biomed Life Sci 2016; 1021:14-29. [DOI: 10.1016/j.jchromb.2015.11.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 11/15/2015] [Accepted: 11/17/2015] [Indexed: 01/10/2023]
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Sun J, Xiao Y, Wang S, Slepian MJ, Wong PK. Advances in Techniques for Probing Mechanoregulation of Tissue Morphogenesis. ACTA ACUST UNITED AC 2015; 20:127-37. [DOI: 10.1177/2211068214554802] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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8
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Ben-Yoav H, Dykstra PH, Bentley WE, Ghodssi R. A controlled microfluidic electrochemical lab-on-a-chip for label-free diffusion-restricted DNA hybridization analysis. Biosens Bioelectron 2014; 64:579-85. [PMID: 25310492 DOI: 10.1016/j.bios.2014.09.069] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 09/22/2014] [Accepted: 09/24/2014] [Indexed: 01/22/2023]
Abstract
Lab-on-a-chip (LOC) devices for electrochemical analysis of DNA hybridization events offer a technology for real-time and label-free assessment of biomarkers at the point-of-care. Here, we present a microfluidic LOC, with 3 × 3 arrayed electrochemical sensors for the analysis of DNA hybridization events. A new dual layer microfluidic valved manipulation system is integrated providing controlled and automated capabilities for high throughput analysis. This feature improves the repeatability, accuracy, and overall sensing performance (Fig. 1). The electrochemical activity of the fabricated microfluidic device is validated and demonstrated repeatable and reversible Nernstian characteristics. System design required detailed analysis of energy storage and dissipation as our sensing modeling involves diffusion-related electrochemical impedance spectroscopy. The effect of DNA hybridization on the calculated charge transfer resistance and the diffusional resistance components is evaluated. We demonstrate a specific device with an average cross-reactivity value of 27.5%. The device yields semilogarithmic dose response and enables a theoretical detection limit of 1 nM of complementary ssDNA target. This limit is lower than our previously reported non-valved device by 74% due to on-chip valve integration providing controlled and accurate assay capabilities.
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Affiliation(s)
- Hadar Ben-Yoav
- MEMS Sensors and Actuators Laboratory (MSAL), Department of Electrical and Computer Engineering, Institute for Systems Research, University of Maryland, College Park, MD 20742, USA.
| | - Peter H Dykstra
- MEMS Sensors and Actuators Laboratory (MSAL), Department of Electrical and Computer Engineering, Institute for Systems Research, University of Maryland, College Park, MD 20742, USA
| | - William E Bentley
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | - Reza Ghodssi
- MEMS Sensors and Actuators Laboratory (MSAL), Department of Electrical and Computer Engineering, Institute for Systems Research, University of Maryland, College Park, MD 20742, USA; Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA.
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9
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Ben-Yoav H, Dykstra PH, Gordonov T, Bentley WE, Ghodssi R. A microfluidic-based electrochemical biochip for label-free DNA hybridization analysis. J Vis Exp 2014:51797. [PMID: 25285529 PMCID: PMC4828060 DOI: 10.3791/51797] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Miniaturization of analytical benchtop procedures into the micro-scale provides significant advantages in regards to reaction time, cost, and integration of pre-processing steps. Utilizing these devices towards the analysis of DNA hybridization events is important because it offers a technology for real time assessment of biomarkers at the point-of-care for various diseases. However, when the device footprint decreases the dominance of various physical phenomena increases. These phenomena influence the fabrication precision and operation reliability of the device. Therefore, there is a great need to accurately fabricate and operate these devices in a reproducible manner in order to improve the overall performance. Here, we describe the protocols and the methods used for the fabrication and the operation of a microfluidic-based electrochemical biochip for accurate analysis of DNA hybridization events. The biochip is composed of two parts: a microfluidic chip with three parallel micro-channels made of polydimethylsiloxane (PDMS), and a 3 x 3 arrayed electrochemical micro-chip. The DNA hybridization events are detected using electrochemical impedance spectroscopy (EIS) analysis. The EIS analysis enables monitoring variations of the properties of the electrochemical system that are dominant at these length scales. With the ability to monitor changes of both charge transfer and diffusional resistance with the biosensor, we demonstrate the selectivity to complementary ssDNA targets, a calculated detection limit of 3.8 nM, and a 13% cross-reactivity with other non-complementary ssDNA following 20 min of incubation. This methodology can improve the performance of miniaturized devices by elucidating on the behavior of diffusion at the micro-scale regime and by enabling the study of DNA hybridization events.
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Affiliation(s)
- Hadar Ben-Yoav
- MEMS Sensors and Actuators Laboratory (MSAL), Department of Electrical and Computer Engineering, Institute for Systems Research, University of Maryland;
| | - Peter H Dykstra
- MEMS Sensors and Actuators Laboratory (MSAL), Department of Electrical and Computer Engineering, Institute for Systems Research, University of Maryland
| | - Tanya Gordonov
- Institute for Bioscience and Biotechnology Research, Fischell Department of Bioengineering, University of Maryland
| | - William E Bentley
- Institute for Bioscience and Biotechnology Research, Fischell Department of Bioengineering, University of Maryland
| | - Reza Ghodssi
- MEMS Sensors and Actuators Laboratory (MSAL), Department of Electrical and Computer Engineering, Institute for Systems Research, University of Maryland
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10
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Nge PN, Rogers CI, Woolley AT. Advances in microfluidic materials, functions, integration, and applications. Chem Rev 2013; 113:2550-83. [PMID: 23410114 PMCID: PMC3624029 DOI: 10.1021/cr300337x] [Citation(s) in RCA: 504] [Impact Index Per Article: 45.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Pamela N. Nge
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602
| | - Chad I. Rogers
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602
| | - Adam T. Woolley
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602
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12
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Gao JG, Riahi R, Sin MLY, Zhang S, Wong PK. Electrokinetic focusing and separation of mammalian cells in conductive biological fluids. Analyst 2012; 137:5215-21. [PMID: 22937529 PMCID: PMC4086461 DOI: 10.1039/c2an35707k] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Active manipulation of cells, such as trapping, focusing, and isolation, is essential for various bioanalytical applications. Herein, we report a hybrid electrokinetic technique for manipulating mammalian cells in physiological fluids. This technique applies a combination of negative dielectrophoretic force and hydrodynamic drag force induced by electrohydrodynamics, which is effective in conductive biological fluids. With a three-electrode configuration, the stable equilibrium positions of cells can be adjusted for separation and focusing applications. Cancer cells and white blood cells can be positioned and isolated into specific locations in the microchannel under both static and dynamic flow conditions. To investigate the sensitivity of the hybrid electrokinetic process, AC voltage, frequency, and bias dependences of the cell velocity were studied systematically. The applicability of the hybrid electrokinetic technique for manipulating cells in physiological samples is demonstrated by continuous focusing of human breast adenocarcinoma spiked in urine, buffy coats, and processed blood samples with 98% capture efficiency.
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Affiliation(s)
- Jian Gao Gao
- Department of Aerospace and Mechanical Engineering, The University of Arizona, Tucson, Arizona 85721, USA
- Department of Chemical Engineering, Shandong Polytechnic University, Jinan 250353, China
| | - Reza Riahi
- Department of Aerospace and Mechanical Engineering, The University of Arizona, Tucson, Arizona 85721, USA
| | - Mandy L. Y. Sin
- Department of Aerospace and Mechanical Engineering, The University of Arizona, Tucson, Arizona 85721, USA
- Department of Urology, Stanford University, Palo Alto, California, 94304, USA
| | - Shufeng Zhang
- Department of Physics, The University of Arizona, Tucson, Arizona 85721, USA
| | - Pak Kin Wong
- Department of Aerospace and Mechanical Engineering, The University of Arizona, Tucson, Arizona 85721, USA
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13
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A microfluidic-based electrochemical biochip for label-free diffusion-restricted DNA hybridization analysis. Biosens Bioelectron 2012; 38:114-20. [DOI: 10.1016/j.bios.2012.05.009] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 04/20/2012] [Accepted: 05/08/2012] [Indexed: 11/22/2022]
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14
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Njoroge SK, Witek MA, Battle KN, Immethun VE, Hupert ML, Soper SA. Integrated continuous flow polymerase chain reaction and micro-capillary electrophoresis system with bioaffinity preconcentration. Electrophoresis 2011; 32:3221-32. [PMID: 22038569 DOI: 10.1002/elps.201100274] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 07/01/2011] [Accepted: 07/04/2011] [Indexed: 12/18/2022]
Abstract
An integrated and modular DNA analysis system is reported that consists of two modules: (i) A continuous flow polymerase chain reaction (CFPCR) module fabricated in a high T(g) (150°C) polycarbonate substrate in which selected gene fragments were amplified using biotin and fluorescently labeled primers accomplished by continuously shuttling small packets of PCR reagents and template through isothermal zones as opposed to heating and cooling large thermal masses typically performed in batch-type thermal reactors. (ii) μCE (micro-capillary electrophoresis) module fabricated in poly(methylmethacrylate) (PMMA), which utilized a bioaffinity selection and purification bed (2.9 μL) to preconcentrate and purify the PCR products generated from the CFPCR module prior to electrophoretic sorting. Biotin-labeled CFPCR products were hydrostatically pumped through the streptavidin-modified bed, where they were extracted onto the surface of micropillars. The affinity bed was also fabricated in PMMA and was populated with an array of microposts (50 μm width; 100 μm height) yielding a total surface area of ∼117 mm(2). This solid-phase extraction (SPE) process demonstrated high selectivity for biotinylated amplicons and utilized the strong streptavidin/biotin interaction (K(d) = 10(-15) M) to generate high recoveries. The SPE selected CFPCR products were thermally denatured and single-stranded DNA released for injection into a 7-cm-long μCE channel for size-based separations and fluorescence detection. The utility of the system was demonstrated using Alu DNA typing for gender and ethnicity determinations as a model. Compared with the traditional cross-T injection procedure typically used for μCE, the affinity pre-concentration and injection procedure generated signal enhancements of 17- to 40-fold, critical for CFPCR thermal cyclers due to Taylor dispersion associated with their operation.
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Affiliation(s)
- Samuel K Njoroge
- Department of Chemistry, Louisiana State University, Baton Rouge, LA, USA
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16
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Sin MLY, Gao J, Liao JC, Wong PK. System Integration - A Major Step toward Lab on a Chip. J Biol Eng 2011; 5:6. [PMID: 21612614 PMCID: PMC3117764 DOI: 10.1186/1754-1611-5-6] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 05/25/2011] [Indexed: 02/08/2023] Open
Abstract
Microfluidics holds great promise to revolutionize various areas of biological engineering, such as single cell analysis, environmental monitoring, regenerative medicine, and point-of-care diagnostics. Despite the fact that intensive efforts have been devoted into the field in the past decades, microfluidics has not yet been adopted widely. It is increasingly realized that an effective system integration strategy that is low cost and broadly applicable to various biological engineering situations is required to fully realize the potential of microfluidics. In this article, we review several promising system integration approaches for microfluidics and discuss their advantages, limitations, and applications. Future advancements of these microfluidic strategies will lead toward translational lab-on-a-chip systems for a wide spectrum of biological engineering applications.
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Affiliation(s)
- Mandy LY Sin
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ 85721, USA
| | - Jian Gao
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ 85721, USA
- Department of Chemical Engineering, Shandong Polytechnic University, Jinan, 250353, China
| | - Joseph C Liao
- Department of Urology, Stanford University, 300 Pasteur Drive, S-287, Stanford, CA 94305, USA
| | - Pak Kin Wong
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ 85721, USA
- Biomedical Engineering and Bio5 Institute, University of Arizona, Tucson, AZ 85721, USA
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17
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Yang W, Yu M, Sun X, Woolley AT. Microdevices integrating affinity columns and capillary electrophoresis for multibiomarker analysis in human serum. LAB ON A CHIP 2010; 10:2527-33. [PMID: 20664867 PMCID: PMC2998056 DOI: 10.1039/c005288d] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Biomarkers in human body fluids have great potential for use in screening for diseases such as cancer and diabetes, diagnosis, determining the effectiveness of treatments, and detecting recurrence. Present 96-well immunoassay technology effectively analyzes large numbers of samples; however, this approach is more expensive and less time effective on single or a few samples. In contrast, microfluidic systems are well suited for assaying small numbers of specimens in a point-of-care setting, provided suitable procedures are developed to work within peak capacity constraints when analyzing complex mixtures like human blood serum. Here, we developed integrated microdevices with an affinity column and capillary electrophoresis channels to isolate and quantitate a panel of proteins in complex matrices. To form an affinity column, a thin film of a reactive polymer was photopolymerized in a microchannel, and four antibodies were covalently immobilized to it. The retained protein amounts were consistent from chip to chip, demonstrating reproducibility. Furthermore, the signals from four fluorescently labeled proteins captured on-column were in the same range after rinsing, indicating the column has little bias toward any of the four antibodies or their antigens. These affinity columns have been integrated with capillary electrophoresis separation, enabling us to simultaneously quantify four protein biomarkers in human blood serum in the low ng mL(-1) range using either a calibration curve or standard addition. Our systems provide a fast, integrated and automated platform for multiple biomarker quantitation in complex media such as human blood serum.
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Affiliation(s)
- Weichun Yang
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA
| | - Ming Yu
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA
| | - Xiuhua Sun
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA
| | - Adam T. Woolley
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA
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