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Kim JS, Kwon SY, Lee JY, Kim SD, Kim DY, Kim H, Jang N, Wang J, Han M, Kong SH. High-throughput multi-gate microfluidic resistive pulse sensing for biological nanoparticle detection. LAB ON A CHIP 2023; 23:1945-1953. [PMID: 36897079 DOI: 10.1039/d2lc01064j] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
A microfluidic resistive pulse sensing technique offers a simple method for detecting and analysing microparticles in various fields, yet it has challenges such as the noise during detection and low throughput as the signal obtained from a small single sensing aperture and particle position is nonuniform. This study presents a microfluidic chip with multiple detection gates in the main channel to enhance the throughput while maintaining a simple operational system. A hydrodynamic sheathless particle focusing on a detection gate by modulation of the channel structure and measurement circuit with a reference gate to minimize the noise during detection is used for detecting resistive pulses. The proposed microfluidic chip can analyse the physical properties of 200 nm polystyrene particles and exosomes from MDA-MB-231 with high sensitivity with an error of <10% and high-throughput screening of more than 200 000 exosomes per seconds. The proposed microfluidic chip can analyse the physical properties with high sensitivity, so that it can be potentially used for exosome detection in biological and in vitro clinical applications.
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Affiliation(s)
- June Soo Kim
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Soon Yeol Kwon
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Jae Yong Lee
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Seung Deok Kim
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Da Ye Kim
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Hyunjun Kim
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Noah Jang
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Jiajie Wang
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Maeum Han
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Seong Ho Kong
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
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2
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A Systematic Study on Transit Time and Its Impact on Accuracy of Concentration Measured by Microfluidic Devices. SENSORS 2019; 20:s20010014. [PMID: 31861439 PMCID: PMC6983024 DOI: 10.3390/s20010014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 12/12/2019] [Accepted: 12/14/2019] [Indexed: 12/22/2022]
Abstract
Gating or threshold selection is very important in analyzing data from a microflow cytometer, which is especially critical in analyzing weak signals from particles/cells with small sizes. It has been reported that using the amplitude gating alone may result in false positive events in analyzing data with a poor signal-to-noise ratio. Transit time (τ) can be set as a gating threshold along with side-scattered light or fluorescent light signals in the detection of particles/cells using a microflow cytometer. In this study, transit time of microspheres was studied systematically when the microspheres passed through a laser beam in a microflow cytometer and side-scattered light was detected. A clear linear relationship between the inverse of the average transit time and total flow rate was found. Transit time was used as another gate (other than the amplitude of side-scattering signals) to distinguish real scattering signals from noise. It was shown that the relative difference of the measured microsphere concentration can be reduced significantly from the range of 3.43%-8.77% to the range of 8.42%-111.76% by employing both amplitude and transit time as gates in analysis of collected scattering data. By using optimized transit time and amplitude gate thresholds, a good correlation with the traditional hemocytometer-based particle counting was achieved (R2 > 0.94). The obtained results suggest that the transit time could be used as another gate together with the amplitude gate to improve measurement accuracy of particle/cell concentration for microfluidic devices.
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3
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Abstract
This critical review summarizes the developments in the integration of micro-optical elements with microfluidic platforms for facilitating detection and automation of bio-analytical applications.
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Affiliation(s)
- Hui Yang
- Institute of Biomedical and Health Engineering
- Shenzhen Institutes of Advanced Technology
- Chinese Academy of Science
- 518055 Shenzhen
- China
| | - Martin A. M. Gijs
- Laboratory of Microsystems
- Ecole Polytechnique Fédérale de Lausanne
- 1015 Lausanne
- Switzerland
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4
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Asghari M, Serhatlioglu M, Ortaç B, Solmaz ME, Elbuken C. Sheathless Microflow Cytometry Using Viscoelastic Fluids. Sci Rep 2017; 7:12342. [PMID: 28955054 PMCID: PMC5617843 DOI: 10.1038/s41598-017-12558-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 09/06/2017] [Indexed: 11/17/2022] Open
Abstract
Microflow cytometry is a powerful technique for characterization of particles suspended in a solution. In this work, we present a microflow cytometer based on viscoelastic focusing. 3D single-line focusing of microparticles was achieved in a straight capillary using viscoelastic focusing which alleviated the need for sheath flow or any other actuation mechanism. Optical detection was performed by fiber coupled light source and photodetectors. Using this system, we present the detection of microparticles suspended in three different viscoelastic solutions. The rheological properties of the solutions were measured and used to assess the focusing performance both analytically and numerically. The results were verified experimentally, and it has been shown that polyethlyene oxide (PEO) and hyaluronic acid (HA) based sheathless microflow cytometer demonstrates similar performance to state-of-the art flow cytometers. The sheathless microflow cytometer was shown to present 780 particles/s throughput and 5.8% CV for the forward scatter signal for HA-based focusing. The presented system is composed of a single capillary to accommodate the fluid and optical fibers to couple the light to the fluid of interest. Thanks to its simplicity, the system has the potential to widen the applicability of microflow cytometers.
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Affiliation(s)
- Mohammad Asghari
- UNAM - National Nanotechnology Research Center, Institute of Materials Science and Nanotechnology, Bilkent University, 06800, Ankara, Turkey
| | - Murat Serhatlioglu
- UNAM - National Nanotechnology Research Center, Institute of Materials Science and Nanotechnology, Bilkent University, 06800, Ankara, Turkey
| | - Bülend Ortaç
- UNAM - National Nanotechnology Research Center, Institute of Materials Science and Nanotechnology, Bilkent University, 06800, Ankara, Turkey
| | - Mehmet E Solmaz
- Department of Electrical and Electronics Engineering, Izmir Katip Celebi University, 35620, Izmir, Turkey
| | - Caglar Elbuken
- UNAM - National Nanotechnology Research Center, Institute of Materials Science and Nanotechnology, Bilkent University, 06800, Ankara, Turkey.
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5
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Lu M, Ozcelik A, Grigsby CL, Zhao Y, Guo F, Leong KW, Huang TJ. Microfluidic Hydrodynamic Focusing for Synthesis of Nanomaterials. NANO TODAY 2016; 11:778-792. [PMID: 30337950 PMCID: PMC6191180 DOI: 10.1016/j.nantod.2016.10.006] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Microfluidics expands the synthetic space such as heat transfer, mass transport, and reagent consumption to conditions not easily achievable in conventional batch processes. Hydrodynamic focusing in particular enables the generation and study of complex engineered nanostructures and new materials systems. In this review, we present an overview of recent progress in the synthesis of nanostructures and microfibers using microfluidic hydrodynamic focusing techniques. Emphasis is placed on distinct designs of flow focusing methods and their associated mechanisms, as well as their applications in material synthesis, determination of reaction kinetics, and study of synthetic mechanisms.
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Affiliation(s)
- Mengqian Lu
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Adem Ozcelik
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Christopher L Grigsby
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708, USA
- Departments of Biomedical Engineering, and Systems Biology, Columbia University, New York, New York, 10027, USA
| | - Yanhui Zhao
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Feng Guo
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Kam W Leong
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708, USA
- Departments of Biomedical Engineering, and Systems Biology, Columbia University, New York, New York, 10027, USA
| | - Tony Jun Huang
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA
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Zhao J, You Z. A Microflow Cytometer with a Rectangular Quasi-Flat-Top Laser Spot. SENSORS 2016; 16:s16091474. [PMID: 27626428 PMCID: PMC5038752 DOI: 10.3390/s16091474] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 09/08/2016] [Indexed: 01/13/2023]
Abstract
This work develops a microflow cytometer, based on a microfluidic chip for three-dimensional (3D) hydrodynamic focusing and a binary optical element (BOE) for shaping and homogenizing a laser beam. The microfluidic chip utilizes sheath flows to confine the sample flow along the channel centerline with a narrow cross section. In addition to hydrodynamic focusing, secondary flows are generated to strengthen the focusing in the vertical direction. In experiments, the chip was able to focus the sample flow with cross sections of 15 μm high and 8-30 μm wide at 5 m/s, under the condition of the sample flow rates between 10 and 120 μL/min. Instead of using the conventional elliptical Gaussian spot for optical detection, we used a specially designed BOE and obtained a 50 μm × 10 μm rectangular quasi-flat-top spot. The microflow cytometer combining the chip and the BOE was tested to count 3, 5, and 7 μm fluorescence microbeads, and the experimental results were comparable to or better than those derived from two commercial instruments.
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Affiliation(s)
- Jingjing Zhao
- State Key Laboratory of Precision Measurement Technology and Instrument, Tsinghua University, Beijing 100084, China.
- Department of Precision Instrument, Tsinghua University, Beijing 100084, China.
- Beijing Laboratory for Biomedical Detection Technology and Instrument, Tsinghua University, Beijing 100084, China.
| | - Zheng You
- State Key Laboratory of Precision Measurement Technology and Instrument, Tsinghua University, Beijing 100084, China.
- Department of Precision Instrument, Tsinghua University, Beijing 100084, China.
- Beijing Laboratory for Biomedical Detection Technology and Instrument, Tsinghua University, Beijing 100084, China.
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7
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Zhao J, You Z. Using binary optical elements (BOEs) to generate rectangular spots for illumination in micro flow cytometer. BIOMICROFLUIDICS 2016; 10:054111. [PMID: 27733892 PMCID: PMC5045444 DOI: 10.1063/1.4963010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Accepted: 09/07/2016] [Indexed: 06/06/2023]
Abstract
This work introduces three rectangular quasi-flat-top spots, which are provided by binary optical elements (BOEs) and utilized for the illumination in a microflow cytometer. The three spots contain, respectively, one, two, and three rectangles (R1, R2, and R3). To test the performance of this mechanism, a microflow cytometer is established by integrating the BOEs and a three-dimensional hydrodynamic focusing chip. Through the experiments of detecting fluorescence microbeads, the three spots present good fluorescence coefficients of variation in comparison with those derived from commercial instruments. Benefiting from a high spatial resolution, when using R1 spot, the micro flow cytometer can perform a throughput as high as 20 000 events per second (eps). Illuminated by R2 or R3 spot, one bead emits fluorescence twice or thrice, thus the velocity can be measured in real time. Besides, the R3 spot provides a long-time exposure, which is conducive to improving fluorescence intensity and the measurement stability. In brief, using the spots shaped and homogenized by BOEs for illumination can increase the performance and the functionality of a micro flow cytometer.
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8
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Testa G, Persichetti G, Bernini R. Micro flow cytometer with self-aligned 3D hydrodynamic focusing. BIOMEDICAL OPTICS EXPRESS 2015; 6:54-62. [PMID: 25657874 PMCID: PMC4317119 DOI: 10.1364/boe.6.000054] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 09/05/2014] [Accepted: 10/13/2014] [Indexed: 05/04/2023]
Abstract
A micro flow cytometer with a single step 3D hydrodynamic flow focusing has been developed. The proposed design is capable to create a single-file particle stream that is self-aligned with an integrated optical fiber-based detection system, regardless of the flow rate ratio between the focusing and core liquids. The design approach provides the ability to adjust the stream size while keeping the position of the focused stream centered with respect to the focusing channel. The device has been fabricated by direct micro milling of PMMA sheets. Experimental validation of the hydrodynamic sheath focusing effect has been presented and sample stream with tuneable size from about 18 to 50 μm was measured. Flow cytometry measurements have been performed by using 10-23 μm fluorescent particles. From the analysis of the signals collected at each transit event we can confirm that the device was capable to align and measure microparticles with a good coefficient of variance.
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Affiliation(s)
- Genni Testa
- Institute for Electromagnetic Sensing of the Environment (IREA), National Research Council, (CNR), Via Diocleziano 328, 80124 Napoli,
Italy
| | - Gianluca Persichetti
- Institute for Electromagnetic Sensing of the Environment (IREA), National Research Council, (CNR), Via Diocleziano 328, 80124 Napoli,
Italy
| | - Romeo Bernini
- Institute for Electromagnetic Sensing of the Environment (IREA), National Research Council, (CNR), Via Diocleziano 328, 80124 Napoli,
Italy
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9
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Guo T, Wei Y, Xu C, Watts BR, Zhang Z, Fang Q, Zhang H, Selvaganapathy PR, Deen MJ. Counting ofEscherichia coliby a microflow cytometer based on a photonic-microfluidic integrated device. Electrophoresis 2014; 36:298-304. [DOI: 10.1002/elps.201400211] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 10/06/2014] [Accepted: 10/09/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Tianyi Guo
- School of Biomedical Engineering; McMaster University; Hamilton Canada
- Institute of Microelectronics; Chinese Academy of Science; Beijing China
| | - Yin Wei
- Department of Engineering Physics; McMaster University; Hamilton Canada
| | - Changqing Xu
- Department of Engineering Physics; McMaster University; Hamilton Canada
| | - Benjamin R. Watts
- Department of Engineering Physics; McMaster University; Hamilton Canada
| | - Zhiyi Zhang
- Information and Communication Technologies; National Research Council of Canada; Ottawa Canada
| | - Qiyin Fang
- School of Biomedical Engineering; McMaster University; Hamilton Canada
- Department of Engineering Physics; McMaster University; Hamilton Canada
| | - Haiying Zhang
- Institute of Microelectronics; Chinese Academy of Science; Beijing China
| | | | - M. Jamal Deen
- School of Biomedical Engineering; McMaster University; Hamilton Canada
- Department of Electrical and Computer Engineering; McMaster University; Hamilton Canada
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10
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Kolb T, Albert S, Haug M, Whyte G. Dynamically reconfigurable fibre optical spanner. LAB ON A CHIP 2014; 14:1186-90. [PMID: 24493284 DOI: 10.1039/c3lc51277k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
In this paper we describe a pneumatically actuated fibre-optic spanner integrated into a microfluidic Lab-on-a-Chip device for the controlled trapping and rotation of living cells. The dynamic nature of the system allows interactive control over the rotation speed with the same optical power. The use of a multi-layer device makes it possible to rotate a cell both in the imaging plane and also in a perpendicular plane allowing tomographic imaging of the trapped living cell. The integrated device allows easy operation and by combining it with high-resolution confocal microscopy we show for the first time that the pattern of rotation can give information regarding the sub-cellular composition of a rotated cell.
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Affiliation(s)
- Thorsten Kolb
- Biophysics Group, Department of Physics, Friedrich-Alexander Universität Erlangen-Nürnberg, Henkestrasse 91, 91052 Erlangen, Germany.
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11
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Piyasena ME, Graves SW. The intersection of flow cytometry with microfluidics and microfabrication. LAB ON A CHIP 2014; 14:1044-59. [PMID: 24488050 PMCID: PMC4077616 DOI: 10.1039/c3lc51152a] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
A modern flow cytometer can analyze and sort particles on a one by one basis at rates of 50,000 particles per second. Flow cytometers can also measure as many as 17 channels of fluorescence, several angles of scattered light, and other non-optical parameters such as particle impedance. More specialized flow cytometers can provide even greater analysis power, such as single molecule detection, imaging, and full spectral collection, at reduced rates. These capabilities have made flow cytometers an invaluable tool for numerous applications including cellular immunophenotyping, CD4+ T-cell counting, multiplex microsphere analysis, high-throughput screening, and rare cell analysis and sorting. Many bio-analytical techniques have been influenced by the advent of microfluidics as a component in analytical tools and flow cytometry is no exception. Here we detail the functions and uses of a modern flow cytometer, review the recent and historical contributions of microfluidics and microfabricated devices to field of flow cytometry, examine current application areas, and suggest opportunities for the synergistic application of microfabrication approaches to modern flow cytometry.
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Affiliation(s)
- Menake E. Piyasena
- Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM USA
- Department of Chemistry, New Mexico Tech, Socorro, NM USA
| | - Steven W. Graves
- Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM USA
- Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, NM USA, FAX: 15052771979; TEL:15052772043
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12
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Erickson RA, Jimenez R. Microfluidic cytometer for high-throughput measurement of photosynthetic characteristics and lipid accumulation in individual algal cells. LAB ON A CHIP 2013; 13:2893-901. [PMID: 23681282 DOI: 10.1039/c3lc41429a] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Commercially viable algal biofuel production requires discovery of new strains, genetic engineering for higher productivity and optimization of growth conditions. To accelerate research in these areas, we developed a microfluidic cytometer that measures forward light scatter, chlorophyll fluorescence induction and lipophilic stain fluorescence at a rate of 100 cells s(-1). The chlorophyll fluorescence data is processed in real-time to measure the fluorescence-based maximum quantum yield, reported as Fv/Fm, to quantify the photochemical energy conversion of each cell. To demonstrate instrument performance, Fv/Fm measurements are obtained for unstressed (nutrient-replete) and stressed (nutrient-limited) cultures of the marine diatom Phaeodactylum tricornutum and are correlated to values obtained in bulk samples using traditional pulse-amplitude-modulating fluorometry. We then use the cytometer to characterize unstressed and stressed P. tricornutum and show that lipid content (as measured by Nile Red fluorescence) is inversely correlated with Fv/Fm. We believe these findings to be the first time that both photosynthetic efficiency and lipid accumulation have been simultaneously evaluated at the single cell level, and that in doing so, the diversity within these populations was revealed.
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Affiliation(s)
- Richard A Erickson
- JILA, University of Colorado-Boulder and National Institute of Standards and Technology, 440 UCB, Boulder, Colorado 80309, USA.
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13
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Chung AJ, Gossett DR, Di Carlo D. Three dimensional, sheathless, and high-throughput microparticle inertial focusing through geometry-induced secondary flows. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2013; 9:685-90. [PMID: 23143944 DOI: 10.1002/smll.201202413] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Indexed: 05/13/2023]
Abstract
A novel inertial focusing platform creates a single-stream microparticle train in a single-focal plane without sheath fluids and external forces, all in a high-throughput manner. The proposed design consists of a low-aspect-ratio straight channel interspersed with a series of constrictions in height arranged orthogonally, making use of inertial focusing and geometry-induced secondary flows. Focusing efficiency as high as 99.77% is demonstrated with throughput as high as 36 000 particles s(-1) for a variety of different sized particles and cells.
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Affiliation(s)
- Aram J Chung
- Department of Bioengineering, California NanoSystems Institute, University of California, Los Angeles, CA 90095, USA
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14
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Martini J, Recht MI, Huck M, Bern MW, Johnson NM, Kiesel P. Time encoded multicolor fluorescence detection in a microfluidic flow cytometer. LAB ON A CHIP 2012; 12:5057-62. [PMID: 23044636 PMCID: PMC3485422 DOI: 10.1039/c2lc40515f] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We describe an optical detection technique that delivers high signal-to-noise discrimination to enable a multi-parameter flow cytometer that combines high performance, robustness, compactness and low cost. The enabling technique is termed "spatially modulated detection" and generates a time-dependent signal as a continuously fluorescing (bio-) particle traverses an optical transmission pattern along the fluidic channel. Correlating the detected signal with the expected transmission pattern achieves high discrimination of the particle signal from background noise. Additionally, the particle speed and its fluorescence emission characteristics are deduced from the correlation analysis. Our method uses a large excitation/emission volume along the fluidic channel in order to increase the total flux of fluorescence light that originates from a particle while requiring minimal optical alignment. Despite the large excitation/detection volume, the mask pattern enables a high spatial resolution in the micron range. This allows for detection and characterization of particles with a separation (in flow direction) comparable to the dimension of individual particles. In addition, the concept is intrinsically tolerant of non-encoded background fluorescence originating from fluorescent components in solution, fluorescing components of the chamber and contaminants on its surface. The optical detection technique is illustrated with experimental results of multicolor detection with a single large area detector by filtering fluorescence emission of different particles through a patterned color mask. Thereby the particles' fluorescence emission spectrum is encoded in a time dependent intensity signal and color information can be extracted from the correlation analysis. The multicolor detection technique is demonstrated by differentiation of micro-beads loaded with PE (Phycoerythrin) and PE-Cy5 that are excited at 532 nm.
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Affiliation(s)
- Joerg Martini
- Palo Alto Research Center, 3333 Coyote Hill Rd., Palo Alto, CA 94304, USA.
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15
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Watts BR, Zhang Z, Xu CQ, Cao X, Lin M. Integration of optical components on-chip for scattering and fluorescence detection in an optofluidic device. BIOMEDICAL OPTICS EXPRESS 2012; 3:2784-93. [PMID: 23162718 PMCID: PMC3493222 DOI: 10.1364/boe.3.002784] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 06/01/2012] [Accepted: 06/13/2012] [Indexed: 05/04/2023]
Abstract
An optofluidic device is demonstrated with photonic components integrated onto the chip for use in fluorescence and scatter detection and counting applications. The device is fabricated by integrating the optical and fluidic components in a single functional layer. Optical excitation on-chip is accomplished via a waveguide integrated with a system of lenses that reforms the geometry of the beam in the microfluidic channel into a specific shape that is more suitable for reliable detection. Separate counting tests by detecting fluorescence and scattered signals from 2.5 and 6.0 μm beads were performed and found to show detection reliability comparable to that of conventional means of excitation and an improvement over other microchip-based designs.
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Affiliation(s)
- Benjamin R Watts
- Department of Engineering Physics, McMaster University, Hamilton, Ontario L8S 4L7, Canada
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16
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Watts BR, Zhang Z, Xu CQ, Cao X, Lin M. A photonic-microfluidic integrated device for reliable fluorescence detection and counting. Electrophoresis 2012; 33:3236-44. [DOI: 10.1002/elps.201200311] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 06/08/2012] [Accepted: 07/01/2012] [Indexed: 11/08/2022]
Affiliation(s)
- Benjamin R. Watts
- Department of Engineering Physics; McMaster University; Hamilton; Ontario; Canada
| | - Zhiyi Zhang
- Institute for Microstructural Sciences; National Research Council of Canada; Ottawa; Ontario; Canada
| | - Chang Qing Xu
- Department of Engineering Physics; McMaster University; Hamilton; Ontario; Canada
| | - Xudong Cao
- Department of Chemical and Biological Engineering; University of Ottawa; Ottawa; Ontario; Canada
| | - Min Lin
- Canadian Food Inspection Agency; Ottawa; Ontario; Canada
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17
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Weber E, Vellekoop MJ. Optofluidic micro-sensors for the determination of liquid concentrations. LAB ON A CHIP 2012; 12:3754-3759. [PMID: 22898709 DOI: 10.1039/c2lc40616k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We present a novel optofluidic device for non-invasive and label-free determination of liquid concentrations. A microfluidic channel filled with the sample solution is hit by laser light in an angle close to the critical angle for total internal reflection. Due to the intentionally defined divergence of the incident beam, parts of the rays will experience total internal reflection while another part will be transmitted. Both reflected and transmitted light signals are recorded and the ratio of these signals is used for sample characterization. The stability compared to single signal analyses is significantly improved, resulting in a resolution of approximately 40 mmol L(-1). The typical working range of the device under investigation is between a few tens of mmol L(-1) and 5 mol L(-1) making it useful for applications in the food industry, for example to determine the amount of phosphates in liquid products.
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Affiliation(s)
- Emanuel Weber
- Institute for Microsensors, -actuators and -systems (IMSAS), MCB, University of Bremen, 28359 Bremen, Germany.
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18
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Mao X, Nawaz AA, Lin SCS, Lapsley MI, Zhao Y, McCoy JP, El-Deiry WS, Huang TJ. An integrated, multiparametric flow cytometry chip using "microfluidic drifting" based three-dimensional hydrodynamic focusing. BIOMICROFLUIDICS 2012; 6:24113-241139. [PMID: 22567082 PMCID: PMC3344854 DOI: 10.1063/1.3701566] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2012] [Accepted: 03/14/2012] [Indexed: 05/04/2023]
Abstract
In this work, we demonstrate an integrated, single-layer, miniature flow cytometry device that is capable of multi-parametric particle analysis. The device integrates both particle focusing and detection components on-chip, including a "microfluidic drifting" based three-dimensional (3D) hydrodynamic focusing component and a series of optical fibers integrated into the microfluidic architecture to facilitate on-chip detection. With this design, multiple optical signals (i.e., forward scatter, side scatter, and fluorescence) from individual particles can be simultaneously detected. Experimental results indicate that the performance of our flow cytometry chip is comparable to its bulky, expensive desktop counterpart. The integration of on-chip 3D particle focusing with on-chip multi-parametric optical detection in a single-layer, mass-producible microfluidic device presents a major step towards low-cost flow cytometry chips for point-of-care clinical diagnostics.
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Fabrication and Performance of a Photonic-Microfluidic Integrated Device. MICROMACHINES 2012. [DOI: 10.3390/mi3010062] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Ju WJ, Fu LM, Yang RJ, Lee CL. Distillation and detection of SO2 using a microfluidic chip. LAB ON A CHIP 2012; 12:622-6. [PMID: 22159042 DOI: 10.1039/c1lc20954j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
A miniaturized distillation system is presented for separating sulfurous acid (H(2)SO(3)) into sulfur dioxide (SO(2)) and water (H(2)O). The major components of the proposed system include a microfluidic distillation chip, a power control module, and a carrier gas pressure control module. The microfluidic chip is patterned using a commercial CO(2) laser and comprises a serpentine channel, a heating zone, a buffer zone, a cooling zone, and a collection tank. In the proposed device, the H(2)SO(3) solution is injected into the microfluidic chip and is separated into SO(2) and H(2)O via an appropriate control of the distillation time and temperature. The gaseous SO(2) is then transported into the collection chamber by the carrier gas and is mixed with DI water. Finally, the SO(2) concentration is deduced from the absorbance measurements obtained using a spectrophotometer. The experimental results show that a correlation coefficient of R(2) = 0.9981 and a distillation efficiency as high as 94.6% are obtained for H(2)SO(3) solutions with SO(2) concentrations in the range of 100-500 ppm. The SO(2) concentrations of two commercial red wines are successfully detected using the developed device. Overall, the results presented in this study show that the proposed system provides a compact and reliable tool for SO(2) concentration measurement purposes.
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Affiliation(s)
- Wei-Jhong Ju
- Department of Engineering Science, National Cheng Kung University, Tainan, 701, Taiwan
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Kennedy MJ, Ladouceur HD, Moeller T, Kirui D, Batt CA. Analysis of a laminar-flow diffusional mixer for directed self-assembly of liposomes. BIOMICROFLUIDICS 2012; 6:44119. [PMID: 24348890 PMCID: PMC3555636 DOI: 10.1063/1.4772602] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Accepted: 12/04/2012] [Indexed: 05/15/2023]
Abstract
The present work describes the operation and simulation of a microfluidic laminar-flow mixer. Diffusive mixing takes place between a core solution containing lipids in ethanol and a sheath solution containing aqueous buffer, leading to self assembly of liposomes. Present device architecture hydrodynamically focuses the lipid solution into a cylindrical core positioned at the center of a microfluidic channel of 125 × 125-μm(2) cross-section. Use of the device produces liposomes in the size range of 100-300 nm, with larger liposomes forming at greater ionic strength in the sheath solution and at lower lipid concentration in the core solution. Finite element simulations compute the concentration distributions of solutes at axial distances of greater than 100 channel widths. These simulations reduce computation time and enable computation at long axial distances by utilizing long hexahedral elements in the axial flow region and fine tetrahedral elements in the hydrodynamic focusing region. Present meshing technique is generally useful for simulation of long microfluidic channels and is fully implementable using comsol Multiphysics. Confocal microscopy provides experimental validation of the simulations using fluorescent solutions containing fluorescein or enhanced green fluorescent protein.
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Affiliation(s)
- Matthew J Kennedy
- NRC Research Associate at Naval Research Laboratory, Chemistry Division, Washington, DC 20375, USA ; Department of Electrical and Computer Engineering, Cornell University, Ithaca, New York 14853, USA
| | - Harold D Ladouceur
- Naval Research Laboratory, Chemistry Division, Washington, DC 20375, USA
| | - Tiffany Moeller
- Department of Food Science, Cornell University, Ithaca, New York 14853, USA
| | - Dickson Kirui
- Department of Biomedical Engineering, Cornell University, Ithaca, New York 14853, USA
| | - Carl A Batt
- Department of Food Science, Cornell University, Ithaca, New York 14853, USA
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