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Kumar JP, Umavathi JC, Dhone AS. Nanofluid containing motile gyrotactic microorganisms squeezed between parallel disks. PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS, PART N: JOURNAL OF NANOMATERIALS, NANOENGINEERING AND NANOSYSTEMS 2023. [DOI: 10.1177/23977914231161448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Advanced nano and microtechnologies for nano/micro-electronic devices have made substantial advances in the past few years. These technologies are rapidly incorporating advanced fluid media such as nanofluids and biological microorganisms. Inspired by bio-nanofluid applications in medicine, biological systems and biotechnology in the present study, mathematical model is evolved for unsteady bio convective conducting nanofluid along with gyrotactic micro-organisms squeezed between parallel disks. The lower disk and upper disks are solids. The temperature field is improved by the methods of haphazard motion of nanoparticles and thermophoresis parameters. The nano-bio transfer model is written as a series of non-linear partial differential equations that are reduced into a set of ordinary differential equations using suitable transforms. The dimensionless problem is then numerically solved by RK-4th order scheme utilizing MATLAB bvp4c solver’s package to investigate the impact of the squeezing parameter, Hartman number, Brownian motion and thermophoresis parameter on motile microorganism velocity, temperature, nanoparticle concentration, and density. The friction factor, Nusselt number, Sherwood number and microorganism number distributions on Hartman number, thermophoresis and Brownian motion factors are also computed. The Brownian motion and the thermophoresis factors of nanoparticles cause an increment in temperature profiles for both suction and injection. The concentration and motile microorganism are both amplified for the Brownian parameter in the case of injection, whereas they are declined for suction and the opposite trend is observed for the thermophoresis parameter. The motile microorganism is deflated for both suction and injection with thermophoresis parameter. Suction and injection adversely affect the transfer properties at the disks. The resistive magnetic body force prevails in the core zone, resulting in a decrease in velocity. The heat generation in squeeze films with motile microorganisms can be successfully removed with magnetic nanoparticles which require a longer serviceability of the lubrication system, bio-medical systems and need for less maintenance and a longer lifespan approach. The finding is pertinent to novel bio-microsystems that combine nanofluid and the bioconvection phenomenon. The percentage increase in heat, mass, and microorganism transport rates is calculated.
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Affiliation(s)
- Jada Prathap Kumar
- Department of Mathematics, Gulbarga University, Kalaburgi, Karnataka, India
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Tuz Zohra F, Uddin MJ, Basir MF, Ismail AIM. Magnetohydrodynamic bio-nano-convective slip flow with Stefan blowing effects over a rotating disc. PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS, PART N: JOURNAL OF NANOMATERIALS, NANOENGINEERING AND NANOSYSTEMS 2019. [DOI: 10.1177/2397791419881580] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Microfluidic-related technologies and micro-electromechanical systems–based microfluidic devices have received applications in science and engineering fields. This article is the study of a mathematical model of steady forced convective flow past a rotating disc immersed in water-based nanofluid with microorganisms. The boundary layer flow of a viscous nanofluid is studied with multiple slip conditions and Stefan blowing effects under the magnetic field influence. The microscopic nanoparticles move randomly and have the characteristics of thermophoresis, and it is being considered that the change in volume fraction of the nanofluid does not affect the thermo-physical properties. The governing equations are nonlinear partial differential equations. At first, the nonlinear partial differential equations are converted to system of nonlinear ordinary differential equations using suitable similarity transformations and then solved numerically. The influence of relevant parameters on velocities, temperature, concentration and motile microorganism density is illustrated and explained thoroughly. This investigation indicated that suction provides a better medium to enhance the transfer rate of heat, mass and microorganisms compared to blowing. This analysis has a wide range engineering application such as electromagnetic micro pumps and nanomechanics.
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Affiliation(s)
- Fatema Tuz Zohra
- School of Mathematical Sciences, Universiti Sains Malaysia, Gelugor, Malaysia
| | - Mohammed Jashim Uddin
- School of Mathematical Sciences, Universiti Sains Malaysia, Gelugor, Malaysia
- Department of Mathematics, American International University-Bangladesh, Dhaka, Bangladesh
| | - Md Faisal Basir
- School of Mathematical Sciences, Universiti Sains Malaysia, Gelugor, Malaysia
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Miller S, Weiss AA, Heineman WR, Banerjee RK. Electroosmotic flow driven microfluidic device for bacteria isolation using magnetic microbeads. Sci Rep 2019; 9:14228. [PMID: 31578397 PMCID: PMC6775156 DOI: 10.1038/s41598-019-50713-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 07/31/2019] [Indexed: 12/13/2022] Open
Abstract
The presence of bacterial pathogens in water can lead to severe complications such as infection and food poisoning. This research proposes a point-of-care electroosmotic flow driven microfluidic device for rapid isolation and detection of E. coli in buffered solution (phosphate buffered saline solution). Fluorescent E. coli bound to magnetic microbeads were driven through the microfluidic device using both constant forward flow and periodic flow switching at concentrations ranging from 2 × 105 to 4 × 107 bacteria/mL. A calibration curve of fluorescent intensity as a function of bacteria concentration was created using both constant and switching flow, showing an increase in captured fluorescent pixel count as concentration increases. In addition, the use of the flow switching resulted in a significant increase in the capture efficiency of E. coli, with capture efficiencies up to 83% ± 8% as compared to the constant flow capture efficiencies (up to 39% ± 11%), with a sample size of 3 µL. These results demonstrate the improved performance associated with the use of the electroosmotic flow switching system in a point-of-care bacterial detection assay.
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Affiliation(s)
- Samuel Miller
- Department of Mechanical and Materials Engineering, University of Cincinnati, 598 Rhodes Hall, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Alison A Weiss
- Department of Molecular Genetics, Biochemistry & Microbiology, University of Cincinnati, 2254 Medical Sciences Building, 231 Albert Sabin Way, Cincinnati, OH, 45267, USA
| | - William R Heineman
- Department of Chemistry, University of Cincinnati, 120 Crosley Tower, PO Box 210172, Cincinnati, OH, 45221, USA
| | - Rupak K Banerjee
- Department of Mechanical and Materials Engineering, University of Cincinnati, 593 Rhodes Hall, ML 0072, University of Cincinnati, Cincinnati, OH, 45221, USA.
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Zohra FT, Uddin MJ, Ismail AIM. Magnetohydrodynamic bio-nanoconvective Naiver slip flow of micropolar fluid in a stretchable horizontal channel. ACTA ACUST UNITED AC 2019. [DOI: 10.1002/htj.21560] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Fatema T. Zohra
- School of Mathematical Sciences; Universiti Sains Malaysia; Penang Malaysia
| | - Mohammed J. Uddin
- School of Mathematical Sciences; Universiti Sains Malaysia; Penang Malaysia
- Faculty of Science and Technology, Mathematics Department; American International University-Bangladesh; Dhaka Bangladesh
| | - Ahamd I. M. Ismail
- School of Mathematical Sciences; Universiti Sains Malaysia; Penang Malaysia
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Miller SA, Heineman WR, Weiss AA, Banerjee RK. Analysis of Magnetic Microbead Capture With and Without Bacteria in a Microfluidic Device Under Different Flow Scenarios. J Med Device 2018. [DOI: 10.1115/1.4040563] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Efficient detection of pathogens is essential for the development of a reliable point-of-care diagnostic device. Magnetophoretic separation, a technique used in microfluidic platforms, utilizes magnetic microbeads (mMBs) coated with specific antigens to bind and remove targeted biomolecules using an external magnetic field. In order to assure reliability and accuracy in the device, the efficient capture of these mMBs is extremely important. The aim of this study was to analyze the effect of an electroosmotic flow (EOF) switching device on the capture efficiency (CE) of mMBs in a microfluidic device and demonstrate viability of bacteria capture. This analysis was performed at microbead concentrations of 2 × 106 beads/mL and 4 × 106 beads/mL, EOF voltages of 650 V and 750 V, and under constant flow and switching flow protocols. Images were taken using an inverted fluorescent microscope and the pixel count was analyzed to determine to fluorescent intensity. A capture zone was used to distinguish which beads were captured versus uncaptured. Under the steady-state flow protocol, CE was determined to range from 31% to 42%, while the switching flow protocol exhibited a CE of 71–85%. The relative percentage increase due to the utilization of the switching protocol was determined to be around two times the CE, with p < 0.05 for all cases. Initial testing using bacteria-bead complexes was also performed in which these complexes were captured under the constant flow protocol to create a calibration curve based on fluorescent pixel count. The calibration curve was linear on a log-log plot, with R2-value of 0.96. The significant increase in CE highlights the effectiveness of flow switching for magnetophoretic separation in microfluidic devices and prove its viability in bacterial analysis.
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Affiliation(s)
- Samuel A. Miller
- Department of Mechanical and Materials Engineering, University of Cincinnati, 598 Rhodes Hall, Cincinnati, OH 45221 e-mail:
| | - William R. Heineman
- Department of Chemistry, University of Cincinnati, 120 Crosley Tower, P.O. Box 210172, Cincinnati, OH 45221 e-mail:
| | - Alison A. Weiss
- Department of Molecular Genetics, Biochemistry & Microbiology, University of Cincinnati, 2254 Medical Sciences Building, 231 Albert Sabin Way, Cincinnati, OH 45267 e-mail:
| | - Rupak K. Banerjee
- Fellow ASME Department of Mechanical and Materials Engineering, University of Cincinnati, 593 Rhodes Hall, ML 0072, Cincinnati, OH 45221 e-mail:
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Fratzl M, Delshadi S, Devillers T, Bruckert F, Cugat O, Dempsey NM, Blaire G. Magnetophoretic induced convective capture of highly diffusive superparamagnetic nanoparticles. SOFT MATTER 2018; 14:2671-2681. [PMID: 29564433 DOI: 10.1039/c7sm02324c] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Micro-magnets producing magnetic field gradients as high as 106 T m-1 have been used to efficiently trap nanoparticles with a magnetic core of just 12 nm in diameter. Particle capture efficiency increases with increasing particle concentration. Comparison of measured capture kinetics with numerical modelling reveals that a threshold concentration exists below which capture is diffusion-driven and above which it is convectively-driven. This comparison also shows that two-way fluid-particle coupling is responsible for the formation of convective cells, the size of which is governed by the height of the droplet. Our results indicate that for a suspension with a nanoparticle concentration suitable for bioassays (around 0.25 mg ml-1), all particles can be captured in less than 10 minutes. Since nanoparticles have a significantly higher surface-to-volume ratio than the more widely used microparticles, their efficient capture should contribute to the development of next generation digital microfluidic lab-on-chip immunoassays.
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Affiliation(s)
- M Fratzl
- Univ. Grenoble Alpes, CNRS, Grenoble INP, G2Elab, 38000 Grenoble, France, 21 Avenue des Martyrs, 38031 Grenoble, France and Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France, 25 Avenue des Martyrs, 38042, Grenoble, France.
| | - S Delshadi
- Univ. Grenoble Alpes, CNRS, Grenoble INP, G2Elab, 38000 Grenoble, France, 21 Avenue des Martyrs, 38031 Grenoble, France and Univ. Grenoble Alpes, CNRS, INSERM, IAB, 38000 Grenoble, France, Site Santé - Allée des Alpes, 38700 La Tronche, France
| | - T Devillers
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France, 25 Avenue des Martyrs, 38042, Grenoble, France.
| | - F Bruckert
- Univ. Grenoble Alpes, CNRS, Grenoble INP, LMGP, 38000 Grenoble, France, 3 parvis Louis Néel, 38016, Grenoble, France
| | - O Cugat
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France, 25 Avenue des Martyrs, 38042, Grenoble, France.
| | - N M Dempsey
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France, 25 Avenue des Martyrs, 38042, Grenoble, France.
| | - G Blaire
- Univ. Grenoble Alpes, CNRS, Grenoble INP, G2Elab, 38000 Grenoble, France, 21 Avenue des Martyrs, 38031 Grenoble, France and Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France, 25 Avenue des Martyrs, 38042, Grenoble, France.
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Huan Y, Park SJ, Chandra Gupta K, Park SY, Kang IK. Slide cover glass immobilized liquid crystal microdroplets for sensitive detection of an IgG antigen. RSC Adv 2017. [DOI: 10.1039/c7ra06386e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Slide cover glass immobilized AIgG conjugated LC microdroplets for optical detection of rabbit IgG antigen through interfacial antibody–antigen interactions.
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Affiliation(s)
- Yue Huan
- Department of Polymer Science and Engineering
- Kyungpook National University
- Daegu 702-701
- South Korea
| | - So Jung Park
- Department of Polymer Science and Engineering
- Kyungpook National University
- Daegu 702-701
- South Korea
| | - Kailash Chandra Gupta
- Department of Polymer Science and Engineering
- Kyungpook National University
- Daegu 702-701
- South Korea
- Polymer Research Laboratory
| | - Soo-Young Park
- Department of Polymer Science and Engineering
- Kyungpook National University
- Daegu 702-701
- South Korea
| | - Inn-Kyu Kang
- Department of Polymer Science and Engineering
- Kyungpook National University
- Daegu 702-701
- South Korea
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8
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Acharya N, Das K, Kundu PK. Framing the effects of solar radiation on magneto-hydrodynamics bioconvection nanofluid flow in presence of gyrotactic microorganisms. J Mol Liq 2016. [DOI: 10.1016/j.molliq.2016.07.023] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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9
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Lee K, Gupta KC, Park SY, Kang IK. Anti-IgG-anchored liquid crystal microdroplets for label free detection of IgG. J Mater Chem B 2016; 4:704-715. [DOI: 10.1039/c5tb02131f] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
AIgG anchored LC microdroplets showing configurational transition from radial (a) to bipolar (b) upon interaction with IgG.
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Affiliation(s)
- Kyubae Lee
- Department of Polymer Science and Engineering
- Kyungpook National University
- Daegu 702-701
- Republic of Korea
| | - Kailash Chandra Gupta
- Department of Polymer Science and Engineering
- Kyungpook National University
- Daegu 702-701
- Republic of Korea
- Polymer Research Laboratory
| | - Soo-Young Park
- Department of Polymer Science and Engineering
- Kyungpook National University
- Daegu 702-701
- Republic of Korea
| | - Inn-Kyu Kang
- Department of Polymer Science and Engineering
- Kyungpook National University
- Daegu 702-701
- Republic of Korea
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Ji T, Liu D, Liu F, Li J, Ruan Q, Song Y, Tian T, Zhu Z, Zhou L, Lin H, Yang C, Wang D. A pressure-based bioassay for the rapid, portable and quantitative detection of C-reactive protein. Chem Commun (Camb) 2016; 52:8452-4. [DOI: 10.1039/c6cc03705d] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A portable method for the rapid detection of the disease biomarker C-reactive protein with a hand-held pressuremeter was developed.
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11
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Lunnoo T, Puangmali T. Capture Efficiency of Biocompatible Magnetic Nanoparticles in Arterial Flow: A Computer Simulation for Magnetic Drug Targeting. NANOSCALE RESEARCH LETTERS 2015; 10:426. [PMID: 26515074 PMCID: PMC4626471 DOI: 10.1186/s11671-015-1127-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 10/16/2015] [Indexed: 06/05/2023]
Abstract
The primary limitation of magnetic drug targeting (MDT) relates to the strength of an external magnetic field which decreases with increasing distance. Small nanoparticles (NPs) displaying superparamagnetic behaviour are also required in order to reduce embolization in the blood vessel. The small NPs, however, make it difficult to vector NPs and keep them in the desired location. The aims of this work were to investigate parameters influencing the capture efficiency of the drug carriers in mimicked arterial flow. In this work, we computationally modelled and evaluated capture efficiency in MDT with COMSOL Multiphysics 4.4. The studied parameters were (i) magnetic nanoparticle size, (ii) three classes of magnetic cores (Fe3O4, Fe2O3, and Fe), and (iii) the thickness of biocompatible coating materials (Au, SiO2, and PEG). It was found that the capture efficiency of small particles decreased with decreasing size and was less than 5 % for magnetic particles in the superparamagnetic regime. The thickness of non-magnetic coating materials did not significantly influence the capture efficiency of MDT. It was difficult to capture small drug carriers (D<200 nm) in the arterial flow. We suggest that the MDT with high-capture efficiency can be obtained in small vessels and low-blood velocities such as micro-capillary vessels.
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Affiliation(s)
- Thodsaphon Lunnoo
- Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand
| | - Theerapong Puangmali
- Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand.
- Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand.
- Nanotec-KKU, Center of Excellence on Advanced Nanomaterials for Energy Production and Storage, Khon Kaen, 40002, Thailand.
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12
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Ultrasensitive and accelerated detection of ciguatoxin by capillary electrophoresis via on-line sandwich immunoassay with rotating magnetic field and nanoparticles signal enhancement. Anal Chim Acta 2015; 888:27-35. [DOI: 10.1016/j.aca.2015.06.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 06/02/2015] [Accepted: 06/03/2015] [Indexed: 01/24/2023]
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13
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Das D, Al-Rjoub MF, Banerjee RK. Enhanced capture of magnetic microbeads using combination of reduced magnetic field strength and sequentially switched electroosmotic flow--a numerical study. J Biomech Eng 2015; 137:051008. [PMID: 25662030 DOI: 10.1115/1.4029748] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Indexed: 11/08/2022]
Abstract
Magnetophoretic immunoassay is a widely used technique in lab-on-chip systems for detection and isolation of target cells, pathogens, and biomolecules. In this method, target pathogens (antigens) bind to specific antibodies coated on magnetic microbeads (mMBs) which are then separated using an external magnetic field for further analysis. Better capture of mMB is important for improving the sensitivity and performance of magnetophoretic assay. The objective of this study was to develop a numerical model of magnetophoretic separation in electroosmotic flow (EOF) using magnetic field generated by a miniaturized magnet and to evaluate the capture efficiency (CE) of the mMBs. A finite-volume solver was used to compute the trajectory of mMBs under the coupled effects of EOF and external magnetic field. The effect of steady and time varying (switching) electric fields (150-450 V/cm) on the CE was studied under reduced magnetic field strength. During switching, the electric potential at the inlet and outlet of the microchannel was reversed or switched, causing reversal in flow direction. The CE was a function of the momentum of the mMB in EOF and the applied magnetic field strength. By switching the electric field, CE increased from 75% (for steady electric field) to 95% for lower electric fields (150-200 V/cm) and from 35% to 47.5% for higher electric fields (400-450 V/cm). The CE was lower at higher EOF electric fields because the momentum of the mMB overcame the external magnetic force. Switching allowed improved CE due to the reversal and decrease in EOF velocity and increase in mMB residence time under the reduced magnetic field strength. These improvements in CE, particularly at higher electric fields, made sequential switching of EOF an efficient separation technique of mMBs for use in high throughput magnetophoretic immunoassay devices. The reduced size of the magnet, along with the efficient mMB separation technique of switching can lead to the development of portable device for detection of target cells, pathogens, and biomolecules.
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Munir A, Zhu Z, Wang J, Zhou HS. Experimental investigation of magnetically actuated separation using tangential microfluidic channels and magnetic nanoparticles. IET Nanobiotechnol 2014; 8:102-10. [PMID: 25014081 DOI: 10.1049/iet-nbt.2012.0023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
A novel continuous switching/separation scheme of magnetic nanoparticles (MNPs) in a sub-microlitre fluid volume surrounded by neodymium permanent magnet is studied in this work using tangential microfluidic channels. Polydimethylsiloxane tangential microchannels are fabricated using a novel micromoulding technique that can be done without a clean room and at much lower cost and time. Negligible switching of MNPs is seen in the absence of magnetic field, whereas 90% of switching is observed in the presence of magnetic field. The flow rate of MNPs solution had dramatic impact on separation performance. An optimum value of the flow rate is found that resulted in providing effective MNP separation at much faster rate. Separation performance is also investigated for a mixture containing non-magnetic polystyrene particles and MNPs. It is found that MNPs preferentially moved from lower microchannel to upper microchannel resulting in efficient separation. The proof-of-concept experiments performed in this work demonstrates that microfluidic bioseparation can be efficiently achieved using functionalised MNPs, together with tangential microchannels, appropriate magnetic field strength and optimum flow rates. This work verifies that a simple low-cost magnetic switching scheme can be potentially of great utility for the separation and detection of biomolecules in microfluidic lab-on-a-chip systems.
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Affiliation(s)
- Ahsan Munir
- Department of Chemical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA
| | - Zanzan Zhu
- Department of Chemical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA
| | - Jianlong Wang
- College of Food Science and Engineering, Northwest A&F University, 28 Xinong Road, Yangling, Shaanxi 712100, People's Republic of China
| | - Hong Susan Zhou
- Department of Chemical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA.
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SHAW S, KAMESWARAN PK, NARAYANA M, SIBANDA P. BIOCONVECTION IN A NON-DARCY POROUS MEDIUM SATURATED WITH A NANOFLUID AND OXYTACTIC MICRO-ORGANISMS. INT J BIOMATH 2014. [DOI: 10.1142/s1793524514500053] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The aim of this paper is to present a continuum model for bioconvection of oxytactic micro-organisms in a non-Darcy porous medium and to investigate the effects of bioconvection and mixed convection on the steady boundary layer flow past a horizontal plate embedded in a porous medium filled with a water-based nanofluid. The governing partial differential equations for momentum, heat, oxygen and micro-organism conservation are reduced to a set of nonlinear ordinary differential equations using similarity transformations that are numerically solved using a built-in MATLAB ODE solver. The effects of the bioconvection parameters on the nanofluid fluid properties, nanoparticle concentration and the density of the micro-organism are analyzed. A comparative analysis of our results with those previously reported in the literature is given. Among the significant findings in this study is that bioconvection parameters highly influence heat, mass and motile micro-organism transfer rates.
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Affiliation(s)
- S. SHAW
- School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg 3209, South Africa
| | - P. K. KAMESWARAN
- School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg 3209, South Africa
| | - M. NARAYANA
- School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg 3209, South Africa
| | - P. SIBANDA
- School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg 3209, South Africa
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16
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Lee JT, Sudheendra L, Kennedy IM. Accelerated immunoassays based on magnetic particle dynamics in a rotating capillary tube with stationary magnetic field. Anal Chem 2012; 84:8317-22. [PMID: 22931580 DOI: 10.1021/ac301848q] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A rapid and simple magnetic particle-based immunoassay has been demonstrated in a capillary mixing system. Antibody-coated micrometer size superparamagnetic polystyrene (SPP) particles were used in an assay for rabbit IgG in a sandwich (noncompetitive) format. The kinetics of the assay was compared between a plate-based system and a single capillary tube. The interaction between the antigen (R-IgG) and the antibody (anti-R-IgG) that was carried by the SPP particles in a rotating capillary was tested under a stationary magnetic field. Competing magnetic and viscous drag forces helped to enhance the interaction between the analyte and the capture antibodies on the particles. The dimensionless Mason number (Mn) was employed to characterize the magnetic particle dynamics; a previously determined critical Mason number (Mn(c)) was employed as a guide to the appropriate experimental conditions of magnetic field strength and rotational speed of the capillary. The advantage of the rotating capillary system included a short assay time and a reduced reactive volume (20 μL). The results show that the immunoassay kinetics were improved by the formation of chains of the SPP particles for the conditions that corresponded to the critical Mason number.
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Affiliation(s)
- Jun-Tae Lee
- Department of Mechanical and Aerospace Engineering, University of California Davis, California 95616, USA
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17
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Stephens JR, Beveridge JS, Williams ME. Analytical methods for separating and isolating magnetic nanoparticles. Phys Chem Chem Phys 2012; 14:3280-9. [PMID: 22306911 DOI: 10.1039/c2cp22982j] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Despite the large body of literature describing the synthesis of magnetic nanoparticles, few analytical tools are commonly used for their purification and analysis. Due to their unique physical and chemical properties, magnetic nanoparticles are appealing candidates for biomedical applications and analytical separations. Yet in the absence of methods for assessing and assuring their purity, the ultimate use of magnetic particles and heterostructures is likely to be limited. In this review, we summarize the separation techniques that have been initially used for this purpose. For magnetic nanoparticles, it is the use of an applied magnetic flux or field gradient that enables separations. Flow based techniques are combined with applied magnetic fields to give methods such as magnetic field flow fractionation and high gradient magnetic separation. Additional techniques have been explored for manipulating particles in microfluidic channels and in mesoporous membranes. Further development of these and new analytical tools for separation and analysis of colloidal particles is critically important to enable the practical use of these, particularly for medicinal purposes.
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Affiliation(s)
- Jason R Stephens
- The Pennsylvania State University, 104 Chemistry Building, University Park, PA 16802, USA
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Kuznetsov AV. Nanofluid bioconvection in water-based suspensions containing nanoparticles and oxytactic microorganisms: oscillatory instability. NANOSCALE RESEARCH LETTERS 2011; 6:100. [PMID: 21711604 PMCID: PMC3211144 DOI: 10.1186/1556-276x-6-100] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 01/25/2011] [Indexed: 05/29/2023]
Abstract
The aim of this article is to propose a novel type of a nanofluid that contains both nanoparticles and motile (oxytactic) microorganisms. The benefits of adding motile microorganisms to the suspension include enhanced mass transfer, microscale mixing, and anticipated improved stability of the nanofluid. In order to understand the behavior of such a suspension at the fundamental level, this article investigates its stability when it occupies a shallow horizontal layer. The oscillatory mode of nanofluid bioconvection may be induced by the interaction of three competing agencies: oxytactic microorganisms, heating or cooling from the bottom, and top or bottom-heavy nanoparticle distribution. The model includes equations expressing conservation of total mass, momentum, thermal energy, nanoparticles, microorganisms, and oxygen. Physical mechanisms responsible for the slip velocity between the nanoparticles and the base fluid, such as Brownian motion and thermophoresis, are accounted for in the model. An approximate analytical solution of the eigenvalue problem is obtained using the Galerkin method. The obtained solution provides important physical insights into the behavior of this system; it also explains when the oscillatory mode of instability is possible in such system.
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Affiliation(s)
- Andrey V Kuznetsov
- Dept, of Mechanical and Aerospace Engineering, North Carolina State University, Campus Box 7910, Raleigh, NC 27695-7910, USA.
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