101
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Ishimatsu R, Kim J, Jing P, Striemer CC, Fang DZ, Fauchet PM, McGrath JL, Amemiya S. Ion-selective permeability of an ultrathin nanoporous silicon membrane as probed by scanning electrochemical microscopy using micropipet-supported ITIES tips. Anal Chem 2011; 82:7127-34. [PMID: 20690617 DOI: 10.1021/ac1005052] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report on the application of scanning electrochemical microscopy (SECM) to the measurement of the ion-selective permeability of porous nanocrystalline silicon membrane as a new type of nanoporous material with potential applications in analytical, biomedical, and biotechnology device development. The reliable measurement of high permeability in the molecularly thin nanoporous membrane to various ions is important for greater understanding of its structure-permeability relationship and also for its successful applications. In this work, this challenging measurement is enabled by introducing two novel features into amperometric SECM tips based on the micropipet-supported interface between two immiscible electrolyte solutions (ITIES) to reveal the important ion-transport properties of the ultrathin nanopore membrane. The tip of a conventional heat-pulled micropipet is milled using the focused ion beam (FIB) technique to be smoother, better aligned, and subsequently, approach closer to the membrane surface, which allows for more precise and accurate permeability measurement. The high membrane permeability to small monovalent ions is determined using FIB-milled micropipet tips to establish a theoretical formula for the membrane permeability that is controlled by free ion diffusion across water-filled nanopores. Moreover, the ITIES tips are rendered selective for larger polyions with biomedical importance, i.e., polyanionic pentasaccharide Arixtra and polycationic peptide protamine, to yield the membrane permeability that is lower than the corresponding diffusion-limited permeability. The hindered transport of the respective polyions is unequivocally ascribed to electrostatic and steric repulsions from the wall of the nanopores, i.e., the charge and size effects.
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Affiliation(s)
- Ryoichi Ishimatsu
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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102
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Mao P, Fu J. Nanofluidic devices for rapid continuous-flow bioseparation. Methods Mol Biol 2011; 790:127-140. [PMID: 21948411 DOI: 10.1007/978-1-61779-319-6_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Compared with conventional gel-based techniques, such as gel electrophoresis, which are routinely used for bioseparation in biology and biomedical laboratories, nanofluidic devices with regular engineered sieving structures offer the potential for faster separation, better resolution, higher throughput, and more convenient sample recovery. Here, we detail the fabrication process of a two-dimensional nanofluidic filter array device and its implementation for rapid continuous-flow separation of biomolecules such as proteins.
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Affiliation(s)
- Pan Mao
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA
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103
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Nguyen QH, Ali M, Bayer V, Neumann R, Ensinger W. Charge-selective transport of organic and protein analytes through synthetic nanochannels. NANOTECHNOLOGY 2010; 21:365701. [PMID: 20699482 DOI: 10.1088/0957-4484/21/36/365701] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We present an experimental demonstration of a synthetic nanoporous membrane suitable for charge-selective transport of ionic species. The surfaces and walls of synthetic nanochannels, fabricated in heavy ion-tracked polyethylene terephthalate membranes are negatively charged due to the presence of carboxylate moieties. These nanofilters discriminate and gate the transport of cations while inhibiting the passage of anions. The permselectivity of these membranes is reversed by converting the carboxylic moieties into terminated amino groups. The positively charged (aminated) membranes facilitate the transport of anions. Based on the same principle, charged biomolecules (bovine serum albumin and lysozyme) are successfully filtered through these membranes. These membranes also exhibit the phenomenon of ion concentration polarization.
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Affiliation(s)
- Quoc Hung Nguyen
- Technische Universität Darmstadt, Fachbereich Material- und Geowissenschaften, Fachgebiet Materialanalytik, Darmstadt, Germany.
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104
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Lazzara TD, Lau KHA, Abou-Kandil AI, Caminade AM, Majoral JP, Knoll W. Polyelectrolyte layer-by-layer deposition in cylindrical nanopores. ACS NANO 2010; 4:3909-3920. [PMID: 20553002 DOI: 10.1021/nn1007594] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Layer-by-layer (LbL) deposition of polyelectrolytes within nanopores in terms of the pore size and the ionic strength was experimentally studied. Anodic aluminum oxide (AAO) membranes, which have aligned, cylindrical, nonintersecting pores, were used as a model nanoporous system. Furthermore, the AAO membranes were also employed as planar optical waveguides to enable in situ monitoring of the LbL process within the nanopores by optical waveguide spectroscopy (OWS). Structurally well-defined N,N-disubstituted hydrazine phosphorus-containing dendrimers of the fourth generation, with peripherally charged groups and diameters of approximately 7 nm, were used as the model polyelectrolytes. The pore diameter of the AAO was varied between 30-116 nm and the ionic strength was varied over 3 orders of magnitude. The dependence of the deposited layer thickness on ionic strength within the nanopores is found to be significantly stronger than LbL deposition on a planar surface. Furthermore, deposition within the nanopores can become inhibited even if the pore diameter is much larger than the diameter of the G4-polyelectrolyte, or if the screening length is insignificant relative to the dendrimer diameter at high ionic strengths. Our results will aid in the template preparation of polyelectrolyte multilayer nanotubes, and our experimental approach may be useful for investigating theories regarding the partitioning of nano-objects within nanopores where electrostatic interactions are dominant. Furthermore, we show that the enhanced ionic strength dependence of polyelectrolyte transport within the nanopores can be used to selectively deposit a LbL multilayer atop a nanoporous substrate.
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Affiliation(s)
- Thomas D Lazzara
- Max Planck Institute for Polymer Research, Ackermannweg 10, D55128, Mainz, Germany
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105
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Kim TS, Dauskardt RH. Molecular mobility under nanometer scale confinement. NANO LETTERS 2010; 10:1955-1959. [PMID: 20392106 DOI: 10.1021/nl101169s] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The mobility of organic molecules under nanoscale confinement differs greatly from that in the bulk. In this study we show that the conventional free volume dependent mobility relationship explained by the free volume theory of diffusion breaks down for diffusion of linear alkane molecules in organosilicate films with connected nanoporosity. Alkane mobility under such nanoscale confinement was observed to decrease with chain length and was lower than that reported in the bulk. While the activation energy for diffusion was similar to that in the bulk, it was found to decrease with chain length exactly opposite to the trend observed in the bulk. This suggests an increasing molecular free volume with chain length. The effects of molecular polarity and pore size on diffusion were also demonstrated. Molecular mobility was found to be suppressed with increasing molecular polarity and decreasing pore size.
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Affiliation(s)
- Taek-Soo Kim
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
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106
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Szymczyk A, Zhu H, Balannec B. Pressure-driven ionic transport through nanochannels with inhomogenous charge distributions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:1214-1220. [PMID: 19735115 DOI: 10.1021/la902355x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The effect of spatially inhomogeneous fixed charge distributions on the pressure-driven transport of ions through cylindrical nanopores have been investigated theoretically by means of an approximate version of the Poisson-Nernst-Planck model that can be used with confidence for moderately charged nanopores with radius smaller than the Debye screening length of the system. Salt rejection rate has been computed as a function of the applied pressure difference for various one-dimensional (1D) unipolar charge distributions and has been compared with that obtained for a homogeneously charged nanochannel with an identical average volume charge density. The ion rejection capabilities of charged nanopores can be optimized by an appropriate distribution of the fixed charge concentration. When ions are forced to enter the nanopores by the end with the lowest fixed charged concentration, the salt rejection rate exhibits a nonmonotonous variation with the applied pressure. This phenomenon has been attributed to the influence of the inhomogeneous charge distribution on the electric field that arises spontaneously so as to maintain the electroneutrality within the nanopore.
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107
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Piruska A, Gong M, Sweedler JV, Bohn PW. Nanofluidics in chemical analysis. Chem Soc Rev 2010; 39:1060-72. [DOI: 10.1039/b900409m] [Citation(s) in RCA: 146] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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108
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Perera DMNT, Ito T. Cyclic voltammetry on recessed nanodisk-array electrodes prepared from track-etched polycarbonate membranes with 10-nm diameter pores. Analyst 2010; 135:172-6. [DOI: 10.1039/b917517b] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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109
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Zangle TA, Mani A, Santiago JG. Theory and experiments of concentration polarization and ion focusing at microchannel and nanochannel interfaces. Chem Soc Rev 2010; 39:1014-35. [DOI: 10.1039/b902074h] [Citation(s) in RCA: 221] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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110
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Levy SL, Craighead HG. DNA manipulation, sorting, and mapping in nanofluidic systems. Chem Soc Rev 2010; 39:1133-52. [DOI: 10.1039/b820266b] [Citation(s) in RCA: 149] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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111
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Schnietz M, Turchanin A, Nottbohm CT, Beyer A, Solak HH, Hinze P, Weimann T, Gölzhäuser A. Chemically functionalized carbon nanosieves with 1-nm thickness. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2009; 5:2651-2655. [PMID: 19787678 DOI: 10.1002/smll.200901283] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Affiliation(s)
- Mark Schnietz
- Fakultät für Physik, Universität Bielefeld, Bielefeld, Germany
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112
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Abstract
Single- and multiple-nanopore membranes are both highly interesting for biosensing and separation processes, as well as their ability to mimic biological membranes. The density of pores, their shape, and their surface chemistry are the key factors that determine membrane transport and separation capabilities. Here, we report silicon nitride (SiN) membranes with fully controlled porosity, pore geometry, and pore surface chemistry. An ultrathin freestanding SiN platform is described with conical or double-conical nanopores of diameters as small as several nanometers, prepared by the track-etching technique. This technique allows the membrane porosity to be tuned from one to billions of pores per square centimeter. We demonstrate the separation capabilities of these membranes by discrimination of dye and protein molecules based on their charge and size. This separation process is based on an electrostatic mechanism and operates in physiological electrolyte conditions. As we have also shown, the separation capabilities can be tuned by chemically modifying the pore walls. Compared with typical membranes with cylindrical pores, the conical and double-conical pores reported here allow for higher fluxes, a critical advantage in separation applications. In addition, the conical pore shape results in a shorter effective length, which gives advantages for single biomolecule detection applications such as nanopore-based DNA analysis.
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113
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Perdue RK, Laws DR, Hlushkou D, Tallarek U, Crooks RM. Bipolar Electrode Focusing: The Effect of Current and Electric Field on Concentration Enrichment. Anal Chem 2009; 81:10149-55. [DOI: 10.1021/ac901913r] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Robbyn K. Perdue
- Department of Chemistry and Biochemistry, Center for Electrochemistry, and the Center for Nano- and Molecular Science and Technology, The University of Texas at Austin, 1 University Station, A5300, Austin, Texas 78712-0165, and Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35032 Marburg, Germany
| | - Derek R. Laws
- Department of Chemistry and Biochemistry, Center for Electrochemistry, and the Center for Nano- and Molecular Science and Technology, The University of Texas at Austin, 1 University Station, A5300, Austin, Texas 78712-0165, and Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35032 Marburg, Germany
| | - Dzmitry Hlushkou
- Department of Chemistry and Biochemistry, Center for Electrochemistry, and the Center for Nano- and Molecular Science and Technology, The University of Texas at Austin, 1 University Station, A5300, Austin, Texas 78712-0165, and Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35032 Marburg, Germany
| | - Ulrich Tallarek
- Department of Chemistry and Biochemistry, Center for Electrochemistry, and the Center for Nano- and Molecular Science and Technology, The University of Texas at Austin, 1 University Station, A5300, Austin, Texas 78712-0165, and Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35032 Marburg, Germany
| | - Richard M. Crooks
- Department of Chemistry and Biochemistry, Center for Electrochemistry, and the Center for Nano- and Molecular Science and Technology, The University of Texas at Austin, 1 University Station, A5300, Austin, Texas 78712-0165, and Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35032 Marburg, Germany
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114
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Sparreboom W, van den Berg A, Eijkel JCT. Principles and applications of nanofluidic transport. NATURE NANOTECHNOLOGY 2009; 4:713-20. [PMID: 19898499 DOI: 10.1038/nnano.2009.332] [Citation(s) in RCA: 446] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The evolution from microfluidic to nanofluidic systems has been accompanied by the emergence of new fluid phenomena and the potential for new nanofluidic devices. This review provides an introduction to the theory of nanofluidic transport, focusing on the various forces that influence the movement of both solvents and solutes through nanochannels, and reviews the applications of nanofluidic devices in separation science and energy conversion.
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Affiliation(s)
- W Sparreboom
- BIOS/Lab on a Chip group, MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands.
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115
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Yan R, Liang W, Fan R, Yang P. Nanofluidic diodes based on nanotube heterojunctions. NANO LETTERS 2009; 9:3820-5. [PMID: 19603791 DOI: 10.1021/nl9020123] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The mechanism of tuning charge transport in electronic devices has recently been implemented into the nanofluidic field for the active control of ion transport in nanoscale channels/pores. Here we report the first synthesis of longitudinal heterostructured SiO(2)/Al(2)O(3) nanotubes. The ionic transport through these nanotube heterojunctions exhibits clear current rectification, a signature of ionic diode behavior. Such nanofluidic diodes could find applications in ion separation and energy conversion.
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Affiliation(s)
- Ruoxue Yan
- Department of Chemistry, University of California, Berkeley, California 94720, USA
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116
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Fu J, Mao P, Han J. Continuous-flow bioseparation using microfabricated anisotropic nanofluidic sieving structures. Nat Protoc 2009; 4:1681-98. [PMID: 19876028 PMCID: PMC2896887 DOI: 10.1038/nprot.2009.176] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The anisotropic nanofluidic-filter (nanofilter) array (ANA) is a unique molecular-sieving structure for separating biomolecules. In this protocol we describe the fabrication of planar and vertical ANA chips and how to perform continuous-flow bioseparation using them. This protocol is most useful for bioengineers who are interested in developing automated multistep chip-based bioanalysis systems and assumes previous cleanroom microfabrication knowledge. The ANA consists of a two-dimensional periodic nanofilter array, and the designed structural anisotropy of ANA causes different-sized or charged biomolecules to follow distinct trajectories under applied electric fields, leading to efficient continuous-flow separation. Using microfluidic channels surrounding the ANA, the fractionated biomolecule streams are collected and routed to different fluid channels or reservoirs for convenient sample recovery and downstream bioanalysis. The ANA is physically robust and can be reused repeatedly. Compared with the conventional gel-based separation techniques, ANA offers the potential for faster separation, higher throughput and more convenient sample recovery.
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Affiliation(s)
- Jianping Fu
- Research Laboratories of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Department of Electrical Engineering and Computer Science, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Pan Mao
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Jongyoon Han
- Department of Electrical Engineering and Computer Science, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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117
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Asatekin A, Mayes AM. Responsive Pore Size Properties of Composite NF Membranes Based on PVDF Graft Copolymers. SEP SCI TECHNOL 2009. [DOI: 10.1080/01496390903212516] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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118
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Choi S, Park JK. Optically coated mirror-embedded microchannel to measure hydrophoretic particle ordering in three dimensions. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2009; 5:2205-2211. [PMID: 19637272 DOI: 10.1002/smll.200900799] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Three-dimensional (3D) measurement of the behavior of microfluidic particles is vital for improving their operational efficiency and characterization. In particular, it is important to measure particle motions in 3D for exact characterization of hydrophoresis, which utilizes 3D convective flows for size separation. Herein, the 3D measurement of hydrophoretic particle ordering for the exact characterization of hydrophoresis by using an optically coated mirror-embedded microchannel is reported. The mirror, ideally at 45 degrees , reflects the side view of the channel and enables 3D positional information to be obtained easily from two different orthogonal-axis images. With this method, it is shown that hydrophoresis is governed by convective vortices and steric hindrance. It is also observed that hydrophoresis enables 3D particle focusing without sheath flows and accurate flow-rate control. The mechanism of hydrophoresis is finally verified by conducting a computational simulation and comparing the simulation results with the experimental measurements. The hydrophoretic method can be straightforwardly integrated as a 3D particle-focusing component in integrated microfluidic systems. The mirror-embedded channel can also be readily fabricated in a single cast of polydimethylsiloxane, thus offering low-cost, easy implementation of 3D particle measurement.
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Affiliation(s)
- Sungyoung Choi
- Department of Bio and Brain Engineering College of Life Science and Bioengineering KAIST 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Republic of Korea
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119
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Li ZR, Liu GR, Han J, Cheng Y, Chen YZ, Wang JS, Hadjiconstantinou NG. Analytical description of Ogston-regime biomolecule separation using nanofilters and nanopores. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2009; 80:041911. [PMID: 19905346 DOI: 10.1103/physreve.80.041911] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Indexed: 05/28/2023]
Abstract
We present a theoretical model describing Ogston (pore size comparable to or larger than the characteristic molecular dimension) sieving of rigid isotropic and anisotropic biomolecules in nanofluidic molecular filter arrays comprising of alternating deep and shallow regions. Starting from a quasi-one-dimensional drift-diffusion description, which captures the interplay between the driving electric force, entropic barrier and molecular diffusion, we derive explicit analytical results for the effective mobility and trapping time. Our results elucidate the effects of field strength, device geometry and entropic barrier height, providing a robust tool for the design and optimization of nanofilter/nanopore systems. Specifically, we show that Ogston sieving becomes negligible when the length of shallow region becomes sufficiently small, mainly due to efficient diffusional transport through the short shallow region. Our theoretical results are in line with experimental observations and provide important design insight for nanofluidic systems.
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Affiliation(s)
- Zi Rui Li
- The Singapore-MIT Alliance, EA-04-10, 4 Engineering Drive 3, Singapore 117576, Singapore
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120
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Peters R. Functionalization of a nanopore: the nuclear pore complex paradigm. BIOCHIMICA ET BIOPHYSICA ACTA 2009; 1793:1533-9. [PMID: 19596381 PMCID: PMC2756448 DOI: 10.1016/j.bbamcr.2009.06.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Revised: 06/26/2009] [Accepted: 06/30/2009] [Indexed: 10/20/2022]
Abstract
Biological cells maintain a myriad of nanopores which, although relying on the same basic small-hole principle, serve a large variety of functions. Here we consider how the nuclear pore complex (NPC), a large nanopore mediating the traffic between genetic material and protein synthesizing apparatus, is functionalized to carry out a set of transport functions. A major parameter of NPC functionalization is a lining of it external and internal surfaces with so-called phenylalanine glycine (FG) proteins. FG proteins integrate a multitude of transport factor binding sites into intrinsically disordered domains. This surprising finding has given rise to a number of transport models assigning direct gating functions to FG proteins. However, recent data suggest that the properties of FG proteins cannot be properly assessed by considering only the purified, transport-factor-stripped NPC. At physiological conditions transport factors may shape FG proteins in a way allotting an essential role to surface diffusion, reconciling tight binding with efficient transport. Thus, NPC studies are revealing both general traits and novel aspects of nanopore functionalization. In addition, they inspire artificial molecule sorters for proteomic and pharmaceutical applications.
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Affiliation(s)
- Reiner Peters
- The Rockefeller University, Laboratory for mass spectrometry and gaseous ion chemistry, 1230 York Avenue, New York, NY 10065, USA.
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121
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Salieb-Beugelaar GB, Dorfman KD, van den Berg A, Eijkel JCT. Electrophoretic separation of DNA in gels and nanostructures. LAB ON A CHIP 2009; 9:2508-2523. [PMID: 19680576 DOI: 10.1039/b905448k] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The development of nanostructure devices has opened the door to new DNA separation techniques and fundamental investigations. With advanced nanotechnologies, artificial gels (e.g. nanopillar arrays, nanofilters) can be manufactured with controlled and ordered geometries. This contrast with gels, where the pores are disordered and the range of available pore sizes is limited by the level of cross-linking and the mechanical properties of the gel. In this review, we recall the theories developed for free-solution and gel electrophoresis (extended Ogston model, biased reptation and entropic trapping) and from this perspective, suggestions for future concepts for fast DNA separation using nanostructures will be given.
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Affiliation(s)
- G B Salieb-Beugelaar
- BIOS/Lab-on-a-Chip Group, Mesa+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500, AE, Enschede, The Netherlands.
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122
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Cheng CM, Kim Y, Yang JM, Leuba SH, Leduc PR. Dynamics of individual polymers using microfluidic based microcurvilinear flow. LAB ON A CHIP 2009; 9:2339-47. [PMID: 19636465 PMCID: PMC2849989 DOI: 10.1039/b907860f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Polymer dynamics play an important role in a diversity of fields including materials science, physics, biology and medicine. The spatiotemporal responses of individual molecules such as biopolymers have been critical to the development of new materials, the expanded understanding of cell structures including cytoskeletal dynamics, and DNA replication. The ability to probe single molecule dynamics however is often limited by the availability of small-scale technologies that can manipulate these systems to uncover highly intricate behaviors. Advances in micro- and nano-scale technologies have simultaneously provided us with valuable tools that can interface with these systems including methods such as microfluidics. Here, we report on the creation of micro-curvilinear flow through a small-scale fluidic approach, which we have been used to impose a flow-based high radial acceleration ( approximately 10(3) g) on individual flexible polymers. We were able to employ this microfluidic-based approach to adjust and control flow velocity and acceleration to observe real-time dynamics of fluorescently labeled lambda-phage DNA molecules in our device. This allowed us to impose mechanical stimulation including stretching and bending on single molecules in localized regimes through a simple and straightforward technology-based method. We found that the flexible DNA molecules exhibited multimodal responses including distinct conformations and controllable curvatures; these characteristics were directly related to both the elongation and bending dynamics dictated by their locations within the curvilinear flow. We analyzed the dynamics of these individual molecules to determine their elongation strain rates and curvatures ( approximately 0.09 microm(-1)) at different locations in this system to probe the individual polymer structural response. These results demonstrate our ability to create high radial acceleration flow and observe real-time dynamic responses applied directly to individual DNA molecules. This approach may also be useful for studying other biologically based polymers including additional nucleic acids, actin filaments, and microtubules and provide a platform to understand the material properties of flexible polymers at a small scale.
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Affiliation(s)
- Chao-Min Cheng
- Departments of Mechanical and Biomedical Engineering and Biological Sciences, Carnegie Mellon University, Scaife Hall, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA.
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123
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Yaroshchuk A, Boiko Y, Makovetskiy A. Ion-rejection, electrokinetic and electrochemical properties of a nanoporous track-etched membrane and their interpretation by means of space charge model. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:9605-14. [PMID: 19585984 DOI: 10.1021/la900737q] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Due to their straight cylindrical pores, nanoporous track-etched membranes are suitable materials for studies of the fundamentals of nanofluidics. In contrast to single nanochannels, the nano/micro interface, in this case, can be quantitatively considered within the scope of macroscopically 1D models. The pressure-induced changes in the concentration of dilute KCl solutions (salt rejection phenomenon) have been studied experimentally with a commercially available nanoporous track-etched membrane of poly (ethylene terephthalate) (pore diameter ca. 21 nm). Besides that, we have also studied the concomitant stationary transmembrane electrical phenomenon (filtration potential) and carried out time-resolved measurements of the electrical response to a rapid pressure switch-off (within 5-10 ms). The latter has enabled us to split the filtration potential into the streaming potential and membrane potential components. In this way, we could also confirm that the observed nonlinearity of filtration potential, as a function of the transmembrane volume flow, was primarily caused by the salt rejection. The results of experimental measurements have been interpreted by means of a space charge model with the surface charge density being a single fitting parameter (the pore size was estimated from the membrane hydraulic permeability). By using the surface charge density fitted to the salt rejection data, the results of electrical measurements could be reproduced theoretically with a typical accuracy of 10% or better. Taking into account the simplifications made in the modeling, this accuracy appears to be good and confirms the quantitative applicability of the basic concept of space charge model to the description of transport properties of dilute electrolyte solutions in nanochannels of ca. 20 nm.
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Affiliation(s)
- Andriy Yaroshchuk
- ICREA and Department of Chemical Engineering, Polytechnic University of Catalonia, Carrer de Jordi Girona, 08034, Barcelona, Spain.
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124
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Abstract
Highly efficient preconcentration is a crucial prerequisite to the identification of important protein biomarkers with extremely low abundance in target biofluids. In this work, poly(dimethylsiloxane) microchips integrated with 10 nm polycarbonate nanopore membranes were utilized as high-speed protein accumulators. Double-sided injection control of electrokinetic fluid flow in the sample channel resulted in highly localized protein accumulation at a very sharp point in the channel cross point. This greatly enhanced the ability to detect very low levels of initial protein concentration. Fluorescein labeled human serum albumin solutions of 30 and 300 pM accumulated to 3 and 30 microM in only 100 s. Initial solutions as low as 0.3 and 3 pM could be concentrated within 200 s to 0.3 and 3 microM, respectively. This demonstrates a approximately 10(5)-10(6) accumulation factor, and an accumulation rate as high as 5000/sec, yielding a >10x improvement over most results reported to date.
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Affiliation(s)
- Dapeng Wu
- Nanoelectronics Lab, University of Cincinnati, Cincinnati, Ohio 45221-0030, USA
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125
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Hlushkou D, Perdue RK, Dhopeshwarkar R, Crooks RM, Tallarek U. Electric field gradient focusing in microchannels with embedded bipolar electrode. LAB ON A CHIP 2009; 9:1903-1913. [PMID: 19532966 DOI: 10.1039/b822404h] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The complex interplay of electrophoretic, electroosmotic, bulk convective, and diffusive mass/charge transport in a hybrid poly(dimethylsiloxane) (PDMS)/glass microchannel with embedded floating electrode is analyzed. The thin floating electrode attached locally to the wall of the straight microchannel results in a redistribution of local field strength after the application of an external electric field. Together with bulk convection based on cathodic electroosmotic flow, an extended field gradient is formed in the anodic microchannel segment. It imparts a spatially dependent electrophoretic force on charged analytes and, in combination with the bulk convection, results in an electric field gradient focusing at analyte-specific positions. Analyte concentration in the enriched zone approaches a maximum value which is independent of its concentration in the supplying reservoirs. A simple approach is shown to unify the temporal behavior of the concentration factors under general conditions.
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Affiliation(s)
- Dzmitry Hlushkou
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35032, Marburg, Germany
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126
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Losic D, Losic D. Preparation of porous anodic alumina with periodically perforated pores. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:5426-31. [PMID: 19391576 DOI: 10.1021/la804281v] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Anodization of aluminum is an excellent nonlithographic alternative to conventional fabrication approaches for low-cost and large-scale synthesis of a variety of nanostructured materials. In this work, the preparation of anodic alumina oxide (AAO) with unique three-dimensional (3D) porous structures that consist of periodically perforated nanopores is reported. The fabrication method combines electrochemical anodization of aluminum and chemical etching. The key feature of this process is cyclic anodization where an oscillatory current signal was applied to create AAO with periodically shaped pore structures. Spatially specific dissolution of the pore walls was directed by modulated pore structures during chemical etching to generate hexagonally ordered arrays of holes with periodic distribution across the pore length.
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Affiliation(s)
- Dusan Losic
- University of South Australia, Ian Wark Research Institute, Mawson Lakes, Adelaide, SA 5095, Australia.
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127
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Davenport M, Rodriguez A, Shea KJ, Siwy ZS. Squeezing ionic liquids through nanopores. NANO LETTERS 2009; 9:2125-8. [PMID: 19354298 DOI: 10.1021/nl900630z] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Room temperature ionic liquids (RTILs) are substances composed entirely of ions and are liquids at or below 100 degrees C. Ionic conductivity of RTIL is one of the most important physical properties of these unique substances that determine their potential applications as a new medium for capacitors, fuel and solar cells as well as in separation systems. The quality of performance of these devices relies on the understanding of ionic transport of RTIL on a nanoscale. In this letter, we use ionic current carried by RTILs in single nanopores as a probe for their nanoscale transport properties. We show that the conductivity of RTILs through nanopores is significantly less than corresponding bulk values. Our experiments allowed us to address the nature of the interaction of these confined RTILs with charged surfaces. Electrostatic interactions of RTILs with nanopores are the basis for the formation of ionic diodes rectifying transport of the constituent ions.
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Affiliation(s)
- Matthew Davenport
- Department of Physics and Astronomy, University of California, Irvine, Irvine, California 92697, USA
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128
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Mani A, Zangle TA, Santiago JG. On the propagation of concentration polarization from microchannel-nanochannel interfaces. Part I: Analytical model and characteristic analysis. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:3898-908. [PMID: 19275187 PMCID: PMC4816500 DOI: 10.1021/la803317p] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We develop two models to describe ion transport in variable-height micro- and nanochannels. For the first model, we obtain a one-dimensional (unsteady) partial differential equation governing flow and charge transport through a shallow and wide electrokinetic channel. In this model, the effects of electric double layer (EDL) on axial transport are taken into account using exact solutions of the Poisson-Boltzmann equation. The second simpler model, which is approachable analytically, assumes that the EDLs are confined to near-wall regions. Using a characteristics analysis, we show that the latter model captures concentration polarization (CP) effects and provides useful insight into its dynamics. Two distinct CP regimes are identified: CP with propagation in which enrichment and depletion shocks propagate outward, and CP without propagation where polarization effects stay local to micro- nanochannel interfaces. The existence of each regime is found to depend on a nanochannel Dukhin number and mobility of the co-ion nondimensionalized by electroosmotic mobility. Interestingly, microchannel dimensions and axial diffusion are found to play an insignificant role in determining whether CP propagates. The steady state condition of propagating CP is shown to be controlled by channel heights, surface chemistry, and co-ion mobility instead of the reservoir condition. Both models are validated against experimental results in Part II of this two-paper series.
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Affiliation(s)
| | | | - Juan G. Santiago
- 440 Escondido Mall, Bldg 530, room 225, Stanford, CA 94305, , Fax: (650) 723-7657
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129
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Asatekin A, Olivetti EA, Mayes AM. Fouling resistant, high flux nanofiltration membranes from polyacrylonitrile-graft-poly(ethylene oxide). J Memb Sci 2009. [DOI: 10.1016/j.memsci.2009.01.029] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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130
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Astumian RD. Generalized fluctuation-dissipation and reciprocal relations for Brownian sieves and molecular machines. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2009; 79:021119. [PMID: 19391718 DOI: 10.1103/physreve.79.021119] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Revised: 01/09/2009] [Indexed: 05/27/2023]
Abstract
A Brownian sieve is a spatially periodic microstructured device that combines the effects of thermal noise, local spatial asymmetry, and external forces to separate particles based on their transport properties. By treating the motion of an individual particle as a cyclical process in which the particle fluctuates away from and returns to the origin of some unit cell, I derive generalized fluctuation-dissipation and reciprocal relations for the averages (and for all moments) of the number of periodic displacements that are exact and valid for arbitrary values of the external forces. These relations hold not only for Brownian sieves, but for all molecular machines in which a nanoscale system couples two chemical, mechanical, or transport processes by a cycle in which the molecular machine itself fluctuates away from and then returns to some arbitrary reference state, in the process doing or receiving work on or from the environment.
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131
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Li ZR, Liu GR, Han J, Chen YZ, Wang JS, Hadjiconstantinou NG. Transport of biomolecules in asymmetric nanofilter arrays. Anal Bioanal Chem 2009; 394:427-35. [DOI: 10.1007/s00216-008-2558-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2008] [Revised: 11/30/2008] [Accepted: 12/01/2008] [Indexed: 10/21/2022]
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132
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Hibara A, Tsukahara T, Kitamori T. Integrated fluidic systems on a nanometer scale and the study on behavior of liquids in small confinement. J Chromatogr A 2009; 1216:673-83. [DOI: 10.1016/j.chroma.2008.12.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Revised: 12/01/2008] [Accepted: 12/03/2008] [Indexed: 01/25/2023]
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133
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Fissell WH, Dubnisheva A, Eldridge AN, Fleischman AJ, Zydney AL, Roy S. High-Performance Silicon Nanopore Hemofiltration Membranes. J Memb Sci 2009; 326:58-63. [PMID: 20054402 DOI: 10.1016/j.memsci.2008.09.039] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Silicon micromachining provides the precise control of nanoscale features that can be fundamentally enabling for miniaturized, implantable medical devices. Concerns have been raised regarding blood biocompatibility of silicon-based materials and their application to hemodialysis and hemofiltration. A high-performance ultrathin hemofiltration membrane with monodisperse slit-shaped pores was fabricated using a sacrificial oxide technique and then surface-modified with poly(ethylene glycol) (PEG). Fluid and macromolecular transport matched model predictions well. Protein adsorption, fouling, and thrombosis were significantly inhibited by the PEG. The membrane retained hydraulic permeability and molecular selectivity during a 90 hour hemofiltration experiment with anticoagulated bovine whole blood. This is the first report of successful prolonged hemofiltration with a silicon nanopore membrane. The results demonstrate feasibility of renal replacement devices based on these membranes and materials.
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Affiliation(s)
- William H Fissell
- Departments of Nephrology and Hypertension, Cleveland Clinic, Cleveland, Ohio
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134
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Choi S, Song S, Choi C, Park JK. Hydrophoretic Sorting of Micrometer and Submicrometer Particles Using Anisotropic Microfluidic Obstacles. Anal Chem 2008; 81:50-5. [DOI: 10.1021/ac801720x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sungyoung Choi
- Department of Bio and Brain Engineering, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Seungjeong Song
- Department of Bio and Brain Engineering, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Chulhee Choi
- Department of Bio and Brain Engineering, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Je-Kyun Park
- Department of Bio and Brain Engineering, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Republic of Korea
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135
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Plecis A, Nanteuil C, Haghiri-Gosnet AM, Chen Y. Electropreconcentration with Charge-Selective Nanochannels. Anal Chem 2008; 80:9542-50. [DOI: 10.1021/ac8017907] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Adrien Plecis
- Laboratoire de Photonique et Nanostructures, CNRS, 91460 Marcoussis, France
| | - Clément Nanteuil
- Laboratoire de Photonique et Nanostructures, CNRS, 91460 Marcoussis, France
| | | | - Yong Chen
- Laboratoire de Photonique et Nanostructures, CNRS, 91460 Marcoussis, France
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136
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Affiliation(s)
- Xiangchun Xuan
- Department of Mechanical Engineering, Clemson University, Clemson, SC, USA
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137
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Zhou J, Xu J, Xie Y, Qu F, Deng Y, Geng L. Semi-crosslinked polyacrylamides as high-resolution and dynamic self-coating sieving matrices for protein capillary electrophoresis. Sci Bull (Beijing) 2008. [DOI: 10.1007/s11434-008-0430-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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138
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Yao X, Ito T, Higgins DA. Grayscale patterning of polymer thin films with nanometer precision by direct-write multiphoton photolithography. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:8939-8943. [PMID: 18646728 DOI: 10.1021/la8008877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The fabrication of arbitrary grayscale patterns in poly(ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) thin films is demonstrated. Patterns are formed by ablative direct-write multiphoton lithography using a sample scanning microscope and 870-nm light from a mode-locked Ti:sapphire laser. The surface profiles of all etched samples are characterized by atomic force microscopy. Grayscale patterns are produced by modulating the laser focus during etching. Quantitative models describing the etch depth as a function of laser power and focus are presented and employed to reproducibly control film patterning. PEDOT:PSS is found to be etched by a combination of linear and nonlinear optical processes. Sensitization by PEDOT in the composite is concluded to facilitiate removal of PSS. An ultimate etch depth precision of 1 nm is achieved.
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Affiliation(s)
- Xiao Yao
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, USA
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139
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Fu J, Mao P, Han J. Artificial molecular sieves and filters: a new paradigm for biomolecule separation. Trends Biotechnol 2008; 26:311-20. [PMID: 18430480 DOI: 10.1016/j.tibtech.2008.02.009] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Revised: 02/28/2008] [Accepted: 02/28/2008] [Indexed: 10/22/2022]
Abstract
Patterned regular sieves and filters with comparable molecular dimensions hold great promise as an alternative to conventional polymeric gels and fibrous membranes to improve biomolecule separation. Recent developments of microfabricated nanofluidic sieves and filters have demonstrated superior performance for both analytical and preparative separation of various physiologically relevant macromolecules, including proteins. The insights gained from designing these artificial molecular sieves and filters, along with the promising results gathered from their first applications, serve to illustrate the impact that they can have on improving future separation of complex biological samples. Further development of artificial sieves and filters with more elaborate geometrical constraints and tailored surface functionality is believed to provide more promising ideals and results for biomolecule separation, which has great implications for proteomic research and biomarker discovery.
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Affiliation(s)
- Jianping Fu
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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140
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Nanochannels fabricated in polydimethylsiloxane using sacrificial electrospun polyethylene oxide nanofibers. ACTA ACUST UNITED AC 2008. [DOI: 10.1116/1.2975199] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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