1
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Mehrafrooz B, Yu L, Siwy Z, Wanunu M, Aksimentiev A. Electro-Osmotic Flow Generation via a Sticky Ion Action. bioRxiv 2023:2023.12.14.571673. [PMID: 38168277 PMCID: PMC10760089 DOI: 10.1101/2023.12.14.571673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Selective transport of ions through nanometer-sized pores is fundamental to cell biology and central to many technological processes such as water desalination and electrical energy storage. Conventional methods for generating ion selectivity include placement of fixed electrical charges at the inner surface of a nanopore through either point mutations in a protein pore or chemical treatment of a solid-state nanopore surface, with each nanopore type requiring a custom approach. Here, we describe a general method for transforming a nanoscale pore into a highly selective, anion-conducting channel capable of generating a giant electro-osmotic effect. Our molecular dynamics simulations and reverse potential measurements show that exposure of a biological nanopore to high concentrations of guanidinium chloride renders the nanopore surface positively charged due to transient binding of guanidinium cations to the protein surface. A comparison of four biological nanopores reveals the relationship between ion selectivity, nanopore shape, composition of the nanopore surface, and electro-osmotic flow. Remarkably, guanidinium ions are also found to produce anion selectivity and a giant electro-osmotic flow in solid-state nanopores via the same mechanism. Our sticky-ion approach to generate electro-osmotic flow can have numerous applications in controlling molecular transport at the nanoscale and for detection, identification, and sequencing of individual proteins.
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Affiliation(s)
- Behzad Mehrafrooz
- Center for Biophysics and Quantitative Biology
- Beckman Institute for Advanced Science and Technology
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Luning Yu
- Department of Physics, Northeastern University, Boston, MA 02115 USA
| | - Zuzanna Siwy
- Department of Physics, University of California at Irvine, Irvine, CA 92697, USA
| | - Meni Wanunu
- Department of Physics, Northeastern University, Boston, MA 02115 USA
- Department of Bioengineering, Northeastern University, Boston, MA 02115, USA
| | - Aleksei Aksimentiev
- Center for Biophysics and Quantitative Biology
- Beckman Institute for Advanced Science and Technology
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois
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2
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Aluru NR, Aydin F, Bazant MZ, Blankschtein D, Brozena AH, de Souza JP, Elimelech M, Faucher S, Fourkas JT, Koman VB, Kuehne M, Kulik HJ, Li HK, Li Y, Li Z, Majumdar A, Martis J, Misra RP, Noy A, Pham TA, Qu H, Rayabharam A, Reed MA, Ritt CL, Schwegler E, Siwy Z, Strano MS, Wang Y, Yao YC, Zhan C, Zhang Z. Fluids and Electrolytes under Confinement in Single-Digit Nanopores. Chem Rev 2023; 123:2737-2831. [PMID: 36898130 PMCID: PMC10037271 DOI: 10.1021/acs.chemrev.2c00155] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
Confined fluids and electrolyte solutions in nanopores exhibit rich and surprising physics and chemistry that impact the mass transport and energy efficiency in many important natural systems and industrial applications. Existing theories often fail to predict the exotic effects observed in the narrowest of such pores, called single-digit nanopores (SDNs), which have diameters or conduit widths of less than 10 nm, and have only recently become accessible for experimental measurements. What SDNs reveal has been surprising, including a rapidly increasing number of examples such as extraordinarily fast water transport, distorted fluid-phase boundaries, strong ion-correlation and quantum effects, and dielectric anomalies that are not observed in larger pores. Exploiting these effects presents myriad opportunities in both basic and applied research that stand to impact a host of new technologies at the water-energy nexus, from new membranes for precise separations and water purification to new gas permeable materials for water electrolyzers and energy-storage devices. SDNs also present unique opportunities to achieve ultrasensitive and selective chemical sensing at the single-ion and single-molecule limit. In this review article, we summarize the progress on nanofluidics of SDNs, with a focus on the confinement effects that arise in these extremely narrow nanopores. The recent development of precision model systems, transformative experimental tools, and multiscale theories that have played enabling roles in advancing this frontier are reviewed. We also identify new knowledge gaps in our understanding of nanofluidic transport and provide an outlook for the future challenges and opportunities at this rapidly advancing frontier.
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Affiliation(s)
- Narayana R Aluru
- Oden Institute for Computational Engineering and Sciences, Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, 78712TexasUnited States
| | - Fikret Aydin
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Martin Z Bazant
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
- Department of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Daniel Blankschtein
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Alexandra H Brozena
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland20742, United States
| | - J Pedro de Souza
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Menachem Elimelech
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut06520-8286, United States
| | - Samuel Faucher
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - John T Fourkas
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland20742, United States
- Institute for Physical Science and Technology, University of Maryland, College Park, Maryland20742, United States
- Maryland NanoCenter, University of Maryland, College Park, Maryland20742, United States
| | - Volodymyr B Koman
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Matthias Kuehne
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Heather J Kulik
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Hao-Kun Li
- Department of Mechanical Engineering, Stanford University, Stanford, California94305, United States
| | - Yuhao Li
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Zhongwu Li
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Arun Majumdar
- Department of Mechanical Engineering, Stanford University, Stanford, California94305, United States
| | - Joel Martis
- Department of Mechanical Engineering, Stanford University, Stanford, California94305, United States
| | - Rahul Prasanna Misra
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Aleksandr Noy
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
- School of Natural Sciences, University of California Merced, Merced, California95344, United States
| | - Tuan Anh Pham
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Haoran Qu
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland20742, United States
| | - Archith Rayabharam
- Oden Institute for Computational Engineering and Sciences, Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, 78712TexasUnited States
| | - Mark A Reed
- Department of Electrical Engineering, Yale University, 15 Prospect Street, New Haven, Connecticut06520, United States
| | - Cody L Ritt
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut06520-8286, United States
| | - Eric Schwegler
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Zuzanna Siwy
- Department of Physics and Astronomy, Department of Chemistry, Department of Biomedical Engineering, University of California, Irvine, Irvine92697, United States
| | - Michael S Strano
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - YuHuang Wang
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland20742, United States
- Maryland NanoCenter, University of Maryland, College Park, Maryland20742, United States
| | - Yun-Chiao Yao
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
- School of Natural Sciences, University of California Merced, Merced, California95344, United States
| | - Cheng Zhan
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Ze Zhang
- Department of Mechanical Engineering, Stanford University, Stanford, California94305, United States
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3
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Abstract
Properties of solid-liquid interfaces and surface charge characteristics mediate ionic and molecular transport through porous systems, affecting many processes such as separations. Herein, we report experiments designed to probe the electrochemical properties of solid-liquid interfaces using a model system of a single polyethylene terephthalate (PET) pore in contact with aqueous and propylene carbonate solutions of LiClO4. First, the existence and polarity of surface charges were inferred from current-voltage curves recorded when a pore was placed in contact with a LiClO4 concentration gradient. Second, the electro-osmotic transport of uncharged polystyrene particles through the PET pore provided information on the polarity and the magnitude of the pore walls' zeta potential. Our experiments show that the PET pores become effectively positively charged when in contact with LiClO4 solutions in propylene carbonate, even though in aqueous LiClO4, the same pores are negatively charged. Additionally, the electro-osmotic velocity of the particles revealed a significantly higher magnitude of the positive zeta potential of the pores in propylene carbonate compared to the magnitude of the negative zeta potential in water. The presented methods of probing the properties of solid-liquid interfaces are expected to be applicable to a wide variety of solid and liquid systems.
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Affiliation(s)
| | - Zuzanna Siwy
- Department of Chemistry, University of California Irvine, Irvine, California 92697, USA
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4
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Siwy Z, Ensinger W, Laube B, Baldwin R. Preface. Anal Chim Acta 2019; 1086:14-15. [DOI: 10.1016/j.aca.2019.09.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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5
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Li T, Li SX, Kong W, Chen C, Hitz E, Jia C, Dai J, Zhang X, Briber R, Siwy Z, Reed M, Hu L. A nanofluidic ion regulation membrane with aligned cellulose nanofibers. Sci Adv 2019; 5:eaau4238. [PMID: 30801009 PMCID: PMC6386557 DOI: 10.1126/sciadv.aau4238] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 01/11/2019] [Indexed: 05/19/2023]
Abstract
The advancement of nanofluidic applications will require the identification of materials with high-conductivity nanoscale channels that can be readily obtained at massive scale. Inspired by the transpiration in mesostructured trees, we report a nanofluidic membrane consisting of densely packed cellulose nanofibers directly derived from wood. Numerous nanochannels are produced among an expansive array of one-dimensional cellulose nanofibers. The abundant functional groups of cellulose enable facile tuning of the surface charge density via chemical modification. The nanofiber-nanofiber spacing can also be tuned from ~2 to ~20 nm by structural engineering. The surface-charge-governed ionic transport region shows a high ionic conductivity plateau of ~2 mS cm-1 (up to 10 mM). The nanofluidic membrane also exhibits excellent mechanical flexibility, demonstrating stable performance even when the membrane is folded 150°. Combining the inherent advantages of cellulose, this novel class of membrane offers an environmentally responsible strategy for flexible and printable nanofluidic applications.
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Affiliation(s)
- Tian Li
- Department of Materials Science and Engineering, University of Maryland College Park, College Park, MD 20742, USA
| | - Sylvia Xin Li
- Department of Physics, Yale University, New Haven, CT 06511, USA
| | - Weiqing Kong
- Department of Materials Science and Engineering, University of Maryland College Park, College Park, MD 20742, USA
| | - Chaoji Chen
- Department of Materials Science and Engineering, University of Maryland College Park, College Park, MD 20742, USA
| | - Emily Hitz
- Department of Materials Science and Engineering, University of Maryland College Park, College Park, MD 20742, USA
| | - Chao Jia
- Department of Materials Science and Engineering, University of Maryland College Park, College Park, MD 20742, USA
| | - Jiaqi Dai
- Department of Materials Science and Engineering, University of Maryland College Park, College Park, MD 20742, USA
| | - Xin Zhang
- Department of Materials Science and Engineering, University of Maryland College Park, College Park, MD 20742, USA
| | - Robert Briber
- Department of Materials Science and Engineering, University of Maryland College Park, College Park, MD 20742, USA
| | - Zuzanna Siwy
- Department of Physics and Astronomy, University of California, Irvine, Irvine, CA 92697, USA
| | - Mark Reed
- Departments of Electrical Engineering and Applied Physics, Yale University, New Haven, CT 06520, USA
| | - Liangbing Hu
- Department of Materials Science and Engineering, University of Maryland College Park, College Park, MD 20742, USA
- Corresponding author.
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6
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Alzahrani H, Antoine C, Baker L, Balme S, Bhattacharya G, Bohn PW, Cai Q, Chikere C, Crooks RM, Das N, Edwards M, Ehi-Eromosele C, Ermann N, Jiang L, Kanoufi F, Kranz C, Long Y, MacPherson J, McKelvey K, Mirkin M, Nichols R, Nogala W, Pelta J, Ren H, Rudd J, Schuhmann W, Siwy Z, Tian Z, Unwin P, Wen L, White H, Willets K, Wu Y, Ying Y. Processes at nanopores and bio-nanointerfaces: general discussion. Faraday Discuss 2018; 210:145-171. [PMID: 30230491 DOI: 10.1039/c8fd90023j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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7
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Gilpin C, Darmon D, Siwy Z, Martens C. Information Dynamics of a Nonlinear Stochastic Nanopore System. Entropy (Basel) 2018; 20:e20040221. [PMID: 33265312 PMCID: PMC7512734 DOI: 10.3390/e20040221] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 03/19/2018] [Accepted: 03/21/2018] [Indexed: 12/22/2022]
Abstract
Nanopores have become a subject of interest in the scientific community due to their potential uses in nanometer-scale laboratory and research applications, including infectious disease diagnostics and DNA sequencing. Additionally, they display behavioral similarity to molecular and cellular scale physiological processes. Recent advances in information theory have made it possible to probe the information dynamics of nonlinear stochastic dynamical systems, such as autonomously fluctuating nanopore systems, which has enhanced our understanding of the physical systems they model. We present the results of local (LER) and specific entropy rate (SER) computations from a simulation study of an autonomously fluctuating nanopore system. We learn that both metrics show increases that correspond to fluctuations in the nanopore current, indicating fundamental changes in information generation surrounding these fluctuations.
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Affiliation(s)
- Claire Gilpin
- Department of Physics and Astronomy, University of California-Irvine, Irvine, CA 92697-4575, USA
- Correspondence:
| | - David Darmon
- Department of Military and Emergency Medicine, Uniformed Services University, Bethesda, MD 20814, USA
| | - Zuzanna Siwy
- Department of Physics and Astronomy, University of California-Irvine, Irvine, CA 92697-4575, USA
| | - Craig Martens
- Department of Chemistry, University of California-Irvine, Irvine, CA 92697-2025, USA
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8
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Alzahrani H, Antoine C, Aoki K, Baker L, Balme S, Bentley C, Bhattacharya G, Bohn PW, Cai Q, Cao C, Commandeur D, Crooks RM, Edwards M, Ewing A, Fu K, Galeyeva A, Gao R, Hersbach T, Hillman R, Hu YX, Jiang L, Kanoufi F, Kranz C, Liu S, Löffler T, Long Y, MacPherson J, McKelvey K, Minteer S, Mirkin M, Mount A, Nichols R, Nogala W, Öhl D, Qiu K, Ren H, Rudd J, Schuhmann W, Siwy Z, Tian Z, Unwin P, Wang Y, Wilde P, Wu Y, Yang Z, Ying Y. Processes at nanoelectrodes: general discussion. Faraday Discuss 2018; 210:235-265. [DOI: 10.1039/c8fd90024h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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9
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Abstract
Our manuscript addresses the issue of probing an effective surface charge that any surface can acquire at the solid/liquid interface. Even if a particle is predicted to be neutral based on its chemical structure, the particle can carry finite surface charges when placed in a solution. We present tools to probe the presence of surface charge densities of meso-particles, characterized with zeta potentials below 10 mV. The tools are based on the resistive-pulse technique, which uses single pores to probe properties of individual objects including molecules, particles, and cells. The presented experiments were performed with particles 280 and 400 nm in diameter and single pores with opening diameter tuned between ∼ 200 nm and one micron. Surface charge properties were probed in two modes: (i) the passage of the particles through pores of diameters larger than the particles, as well as (ii) an approach curve of a particle to a pore that is smaller than the particle diameter. The curve in the latter mode has a biphasic character starting with a low-amplitude current decrease, followed by a current enhancement reaching an amplitude of ∼10% of the baseline current. The current increase was long-lasting and stable, and shown to strongly depend on the particle surface charge density. The results are explained via voltage-modulation of ionic concentrations in the pore.
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Affiliation(s)
- Yinghua Qiu
- Department of Physics and Astronomy, University of California, Irvine, CA 92697, USA.
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10
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11
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Abstract
DNA strands can be analyzed at the single-molecule level by isolating them inside nanoscale holes. The strategy is used for the label-free and portable sequencing with nanopores. Nanochannels can also be applied to map genomes with high resolution, as shown by Jeffet et al. in this issue of ACS Nano. Here, we compare the two strategies in terms of biophysical similarities and differences and describe that both are complementary and can improve the DNA analysis for genomic research and diagnostics.
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Affiliation(s)
- Stefan Howorka
- Department of Chemistry, Institute of Structural Molecular Biology, University College London , London WC1H 0AJ, United Kingdom
| | - Zuzanna Siwy
- Department of Physics and Astronomy, University of California, Irvine , 210G Rowland Hall, Irvine, California 92697, United States
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12
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Yang C, Menestrina J, Hinkle P, Vlassiouk I, Siwy Z. Charge Induced Rectification in Single Nanopores. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.3486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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13
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Buchsbaum S, Guo S, Hinkle P, Meshot E, Pham A, Siwy Z, Fornasiero F. Anomalous Ionic Conductance in Carbon Nanotube Nanochannels. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.2698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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14
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Qiu Y, Hinkle P, Yang C, Vlassiouk IV, Siwy Z. Anomalous Transit Time and Pulse Amplitude of Highly Charged Particles in Resistive Pulsing. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.2704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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15
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Hinkle P, Qiu Y, Yang C, Siwy Z, Imhof A, Bakker H. A New Procedure for Measuring Particle Length using the Resistive Pulse Technique with Irregular Single Micropores. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.2706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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16
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Ramirez P, Gomez V, Cervera J, Nasir S, Ali M, Ensinger W, Siwy Z, Mafe S. Voltage-controlled current loops with nanofluidic diodes electrically coupled to solid state capacitors. RSC Adv 2016. [DOI: 10.1039/c6ra08277g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Nanofluidic diodes electrically coupled to solid state capacitors show electrical properties reminiscent of a resistor with memory.
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Affiliation(s)
- P. Ramirez
- Departament de Física Aplicada
- Universitat Politècnica de València
- E-46022 València
- Spain
| | - V. Gomez
- Departament de Física Aplicada
- Universitat Politècnica de València
- E-46022 València
- Spain
| | - J. Cervera
- Departament de Física de la Tierra i Termodinàmica
- Universitat de València
- E-46100 Burjassot
- Spain
| | - S. Nasir
- Department of Material- and Geo-Sciences
- Materials Analysis
- Technische Universität Darmstadt
- D-64287 Darmstadt
- Germany
| | - M. Ali
- Department of Material- and Geo-Sciences
- Materials Analysis
- Technische Universität Darmstadt
- D-64287 Darmstadt
- Germany
| | - W. Ensinger
- Department of Material- and Geo-Sciences
- Materials Analysis
- Technische Universität Darmstadt
- D-64287 Darmstadt
- Germany
| | - Z. Siwy
- Department of Physics and Astronomy
- University of California
- Irvine
- USA
| | - S. Mafe
- Departament de Física de la Tierra i Termodinàmica
- Universitat de València
- E-46100 Burjassot
- Spain
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17
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Plett TS, Gamble T, Gillette E, Siwy Z. Ion Transport Through Synthetic Nanopores Deposited in Porous Manganese Oxide Wires. Biophys J 2015. [DOI: 10.1016/j.bpj.2014.11.952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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18
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Yang C, Hinkle P, Melnikov D, Bakker HE, Imhof A, Toimil-Molares E, Gracheva M, Siwy Z. Pores with Undulating Opening Diameter can Determine Particles by Size and Shape. Biophys J 2015. [DOI: 10.1016/j.bpj.2014.11.1791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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19
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Guo S, Buchsbaum SF, Meshot ER, Davenport MW, Siwy Z, Fornasiero F. Giant Conductance and Anomalous Concentration Dependence in Sub-5 nm Carbon Nanotube Nanochannels. Biophys J 2015. [DOI: 10.1016/j.bpj.2014.11.967] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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20
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Menestrina J, Yang C, Vlassiouk IV, Siwy Z. Electrophoresis and Electroomosis Influence Local Ionic Concentrations and Shape of Ion Current Pulses in Resistive-Pulse Based Detection. Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.1262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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21
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Gamble TP, Pietschmann JF, Decker K, Aksimentiev A, Siwy Z. Binding of Alkali Metals to Pore Walls in Nanopores Modulates Transmembrane Ion Current and Ionic Rectification. Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.1260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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22
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Guo S, Davenport M, Meshot E, Buchsbaum S, Siwy Z, Fornasiero F. A Simple, Single-Carbon-Nanotube Nanofludic Platform for Fundamental Transport Studies. Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.1245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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23
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Buchsbaum SF, Mitchell N, Martin H, Wiggin M, Marziali A, Coveney PV, Siwy Z, Howorka S. Disentangling Steric and Electrostatic Factors in Nanoscale Transport through Confined Space. Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.1244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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24
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Buchsbaum SF, Mitchell N, Martin H, Wiggin M, Marziali A, Coveney PV, Siwy Z, Howorka S. Disentangling steric and electrostatic factors in nanoscale transport through confined space. Nano Lett 2013; 13:3890-3896. [PMID: 23819625 DOI: 10.1021/nl401968r] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The voltage-driven passage of biological polymers through nanoscale pores is an analytically, technologically, and biologically relevant process. Despite various studies on homopolymer translocation there are still several open questions on the fundamental aspects of pore transport. One of the most important unresolved issues revolves around the passage of biopolymers which vary in charge and volume along their sequence. Here we exploit an experimentally tunable system to disentangle and quantify electrostatic and steric factors. This new, fundamental framework facilitates the understanding of how complex biopolymers are transported through confined space and indicates how their translocation can be slowed down to enable future sensing methods.
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Affiliation(s)
- Steven F Buchsbaum
- School of Physical Sciences, University of California, Irvine, California 92697, United States
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Pietschmann JF, Wolfram MT, Burger M, Trautmann C, Nguyen G, Pevarnik M, Bayer V, Siwy Z. Rectification properties of conically shaped nanopores: consequences of miniaturization. Phys Chem Chem Phys 2013; 15:16917-26. [DOI: 10.1039/c3cp53105h] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Nguyen G, Buchsbaum S, Siwy Z. Voltage-Gated Synthetic Pores for Controlled Transport of Ions and Neutral Molecules. Biophys J 2013. [DOI: 10.1016/j.bpj.2012.11.2877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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27
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Nguyen G, Howorka S, Siwy Z. Voltage Gating of Abiotic Nanopores with Electromechanical DNA Gates. Biophys J 2012. [DOI: 10.1016/j.bpj.2011.11.1104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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28
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Pevarnik M, Healy K, Siwy Z. Polystyrene Beads as a Model System for Virus Particles Reveal Pore Substructure as they Translocate. Biophys J 2012. [DOI: 10.1016/j.bpj.2011.11.3881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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29
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Ali M, Ramirez P, Tahir MN, Mafe S, Siwy Z, Neumann R, Tremel W, Ensinger W. Biomolecular conjugation inside synthetic polymer nanopores via glycoprotein-lectin interactions. Nanoscale 2011; 3:1894-1903. [PMID: 21423941 DOI: 10.1039/c1nr00003a] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We demonstrate the supramolecular bioconjugation of concanavalin A (Con A) protein with glycoenzyme horseradish peroxidase (HRP) inside single nanopores, fabricated in heavy ion tracked polymer membranes. Firstly, the HRP-enzyme was covalently immobilized on the inner wall of the pores using carbodiimide coupling chemistry. The immobilized HRP-enzyme molecules bear sugar (mannose) groups available for the binding of Con A protein. Secondly, the bioconjugation of Con A on the pore wall was achieved through its biospecific interactions with the mannose residues of the HRP enzyme. The immobilization of biomolecules inside the nanopore leads to the reduction of the available area for ionic transport, and this blocking effect can be exploited to tune the conductance and selectivity of the nanopore in aqueous solution. Both cylindrical and conical nanopores were used in the experiments. The possibility of obtaining two or more conductance states (output), dictated by the degree of nanopore blocking resulted from the different biomolecules in solution (input), as well as the current rectification properties obtained with the conical nanopore, could also allow implementing information processing at the nanometre scale. Model simulations based on the transport equations further verify the feasibility of the sensing procedure that involves concepts from supramolecular chemistry, molecular imprinting, recognition, and nanotechnology.
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Affiliation(s)
- Mubarak Ali
- Technische Universität Darmstadt, Fachbereich Material-u. Geowissenschaften, Fachgebiet Materialanalytik, Petersenstraβe 23, D-64287, Darmstadt, Germany.
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Ali M, Tahir MN, Siwy Z, Neumann R, Tremel W, Ensinger W. Hydrogen Peroxide Sensing with Horseradish Peroxidase-Modified Polymer Single Conical Nanochannels. Anal Chem 2011; 83:1673-80. [DOI: 10.1021/ac102795a] [Citation(s) in RCA: 153] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Mubarak Ali
- Technische Universität Darmstadt, Fachbereich Material-u. Geowissenschaften, Fachgebiet Materialanalytik, Petersenstrasse 23, D-64287 Darmstadt, Germany
- GSI Helmholtzzentrum für Schwerionenforschung, Planckstrasse 1, D-64291 Darmstadt, Germany
| | - Muhammad Nawaz Tahir
- Department of Chemistry, Johannes Gutenberg-Universität, Duesbergweg 10-14, 55099 Mainz, Germany
| | - Zuzanna Siwy
- Department of Physics and Astronomy, University of California, Irvine, California 92697, United States
| | - Reinhard Neumann
- GSI Helmholtzzentrum für Schwerionenforschung, Planckstrasse 1, D-64291 Darmstadt, Germany
| | - Wolfgang Tremel
- Department of Chemistry, Johannes Gutenberg-Universität, Duesbergweg 10-14, 55099 Mainz, Germany
| | - Wolfgang Ensinger
- Technische Universität Darmstadt, Fachbereich Material-u. Geowissenschaften, Fachgebiet Materialanalytik, Petersenstrasse 23, D-64287 Darmstadt, Germany
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31
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Powell M, Healy K, Davenport M, Niya S, Baker L, Letant S, Siwy Z. Noise Properties of Ion Current in Rectifying Nanopores. Biophys J 2011. [DOI: 10.1016/j.bpj.2010.12.3504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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32
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Powell M, Vlassiouk I, Letant S, Siwy Z. Studying Voltage Dependent Noise in Polymer and Solid State Nanopores. Biophys J 2010. [DOI: 10.1016/j.bpj.2009.12.3271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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33
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Pevarnik M, Davenport M, Brailsford J, Shea K, Siwy Z. Hydrophobic Gating in Synthetic Nanopores. Biophys J 2010. [DOI: 10.1016/j.bpj.2009.12.3268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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34
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Davenport M, Shea K, Siwy Z. Conductivity of Room Temperature Ionic Liquids in Single Nanopores. Biophys J 2009. [DOI: 10.1016/j.bpj.2008.12.3841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Abstract
Recently reported experimental and theoretical studies of nanofluidic nonlinear devices, such as bipolar and unipolar ionic diodes, have yet to answer the question about the possibility of their further miniaturization. In this Article, we theoretically investigate the effects of size reduction, applied bias, and solution ionic strength in such devices. We compare the numerical solutions of the Poisson, Nernst-Planck (PNP), and Navier-Stokes (NS) equations with their one-dimensional, analytical approximations. We demonstrate that the contribution of electroosmosis is insignificant and find analytical approximations to PNP for bipolar and unipolar diodes that are in good agreement with numerical 3D solutions. We identify the minimal dimensions for such diodes that demonstrate ion current rectification behavior and demonstrate the importance of the edge effect in very short diodes.
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Affiliation(s)
- Ivan Vlassiouk
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA.
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37
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Abstract
There has been an increasing interest in single nanochannel ionic devices, such as ionic filters that control the type of transported ions and ionic diodes that rectify the ionic flow. In this article, we theoretically investigate the importance of the dimensions, surface charge, electrolyte concentration, and applied bias on nanopore performance. We compare numerical solutions of the Poisson, Nernst-Planck (PNP), and Navier-Stokes (NS) equations with their one-dimensional, analytical approximations. We show that by decreasing the length of the nanopore, the ionic current and ionic selectivity become affected by processes outside the nanochannel. The contribution of electroosmosis is noticeable, especially for highly charged nanochannels, but is insignificant, justifying the use of the simple one-dimensional approximation in many cases. Estimates for the critical electric field at which the nanopore selectivity decreases and the ion current starts to saturate are provided.
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Affiliation(s)
- Ivan Vlassiouk
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA.
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38
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Pépy G, Boesecke P, Kuklin A, Manceau E, Schiedt B, Siwy Z, Toulemonde M, Trautmann C. Cylindrical nanochannels in ion-track polycarbonate membranes studied by small-angle X-ray scattering. J Appl Crystallogr 2007. [DOI: 10.1107/s0021889807000088] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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39
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Fraser SP, Diss JKJ, Chioni AM, Mycielska ME, Pan H, Yamaci RF, Pani F, Siwy Z, Krasowska M, Grzywna Z, Brackenbury WJ, Theodorou D, Koyutürk M, Kaya H, Battaloglu E, De Bella MT, Slade MJ, Tolhurst R, Palmieri C, Jiang J, Latchman DS, Coombes RC, Djamgoz MBA. Voltage-gated sodium channel expression and potentiation of human breast cancer metastasis. Clin Cancer Res 2006; 11:5381-9. [PMID: 16061851 DOI: 10.1158/1078-0432.ccr-05-0327] [Citation(s) in RCA: 339] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Ion channel activity is involved in several basic cellular behaviors that are integral to metastasis (e.g., proliferation, motility, secretion, and invasion), although their contribution to cancer progression has largely been ignored. The purpose of this study was to investigate voltage-gated Na(+) channel (VGSC) expression and its possible role in human breast cancer. EXPERIMENTAL DESIGN Functional VGSC expression was investigated in human breast cancer cell lines by patch clamp recording. The contribution of VGSC activity to directional motility, endocytosis, and invasion was evaluated by in vitro assays. Subsequent identification of the VGSC alpha-subunit(s) expressed in vitro was achieved using reverse transcription-PCR, immunocytochemistry, and Western blot techniques and used to investigate VGSCalpha expression and its association with metastasis in vivo. RESULTS VGSC expression was significantly up-regulated in metastatic human breast cancer cells and tissues, and VGSC activity potentiated cellular directional motility, endocytosis, and invasion. Reverse transcription-PCR revealed that Na(v)1.5, in its newly identified "neonatal" splice form, was specifically associated with strong metastatic potential in vitro and breast cancer progression in vivo. An antibody specific for this form confirmed up-regulation of neonatal Na(v)1.5 protein in breast cancer cells and tissues. Furthermore, a strong correlation was found between neonatal Na(v)1.5 expression and clinically assessed lymph node metastasis. CONCLUSIONS Up-regulation of neonatal Na(v)1.5 occurs as an integral part of the metastatic process in human breast cancer and could serve both as a novel marker of the metastatic phenotype and a therapeutic target.
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Affiliation(s)
- Scott P Fraser
- Neuroscience Solutions to Cancer Research Group, Department of Biological Sciences, Imperial College London, UK
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Abstract
There is increasing interest in the concept of using nanopores as the sensing elements in biosensors. The nanopore most often used is the alpha-hemolysin protein channel, and the sensor consists of a single channel embedded within a lipid bilayer membrane. An ionic current is passed through the channel, and analyte species are detected as transient blocks in this current associated with translocation of the analyte through the channel-stochastic sensing. While this is an extremely promising sensing paradigm, it would be advantageous to eliminate the very fragile lipid bilayer membrane and perhaps to replace the biological nanopore with an abiotic equivalent. We describe here a new family of protein biosensors that are based on conically shaped gold nanotubes embedded within a mechanical and chemically robust polymeric membrane. While these sensors also function by passing an ion current through the nanotube, the sensing paradigm is different from the previous devices in that a transient change in the current is not observed. Instead, the protein analyte binds to a biochemical molecular-recognition agent at the mouth of the conical nanotube, resulting in complete blockage of the ion current. Three different molecular-recognition agents, and correspondingly three different protein analytes, were investigated: (i) biotin/streptavidin, (ii) protein-G/immunoglobulin, and (iii) an antibody to the protein ricin with ricin as the analyte.
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Affiliation(s)
- Zuzanna Siwy
- Department of Chemistry and Center for Research at the Bio/Nano Interface, University of Florida, Gainesville, Florida 32611-7200, USA
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Abstract
We show that diffusion currents for a membrane containing a single conical nanopore with a fixed surface charge and small enough opening diameter depend on the concentration gradient direction. We interpret the results based on the effect of salt concentration on the thickness of the electrical double layer within the nanopore associated with the nanopore's surface charge and the distribution of electric fields inside the pore. The experimental observations are described by a diffusional model based on the Smoluchowski-Nernst-Planck equation.
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Affiliation(s)
- Z Siwy
- University of Florida, Department of Chemistry, Gainesville, Florida 32611, USA
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Abstract
There is considerable interest in developing chemical devices that mimic the function of biological ion channels. We recently described such a device, which consisted of a single conically shaped gold nanotube embedded within a polymeric membrane. This device mimicked one of the key functions of voltage-gated ion channels: the ability to strongly rectify the ionic current flowing through it. The data obtained were interpreted using a simple electrostatic model. While the details are still being debated, it is clear that ion-current-rectification in biological ion channels is more complicated and involves physical movement of an ionically charged portion of the channel in response to a change in the transmembrane potential. We report here artificial ion channels that rectify the ion current flowing through them via this "electromechanical" mechanism. These artificial channels are also based on conical gold nanotubes, but with the critical electromechanical response provided by single-stranded DNA molecules attached to the nanotube walls.
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Affiliation(s)
- C Chad Harrell
- Department of Chemistry and Center for Research at the Bio/Nano Interface, University of Florida, Gainesville, Florida 32611-7200, USA
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43
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Abstract
Ion channels are protein pores that span cell membranes and open and close in response to stimuli like changes in the transmembrane potential, binding of a ligand, or mechanical stress. When open, ions pass through the pore, and hence across the cell membrane, and when closed, ion-transport is precluded. Hence, these channels are nanodevices that have a current-rectification function. There is intense research effort aimed at understanding the molecular-level mechanism for this function. One approach for elucidating the mechanism is to construct a simple abiotic system that mimics this function and to use the mechanistic details of this mimic as a guide to understand the more complex biological channel. We describe here such an abiotic mimic: a synthetic membrane that contains a single conical gold nanotube. The advantage of this mimic is that the surface charge and chemistry of the nanotube wall can be varied, at will, by judicious choice of electrolyte or by thiol chemisorption. This has allowed us to make conical Au nanotubes that rectify the ion current and, just as importantly, to definitively elucidate the mechanism of this function.
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Affiliation(s)
- Zuzanna Siwy
- Department of Chemistry, Center for Research at the Bio/Nano Interface, University of Florida, Gainesville, FL 32611-7200, USA
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45
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Siwy Z, Mycielska ME, Djamgoz MBA. Statistical and fractal analyses of rat prostate cancer cell motility in a direct current electric field: comparison of strongly and weakly metastatic cells. Eur Biophys J 2003; 32:12-21. [PMID: 12632202 DOI: 10.1007/s00249-002-0267-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2002] [Revised: 10/17/2002] [Accepted: 10/24/2002] [Indexed: 10/25/2022]
Abstract
The problems addressed here comprised (1) possible differences in galvanotactic properties of strongly versus weakly metastatic rat prostate cancer cells, with MAT-LyLu and AT-2 as examples, respectively; (2) quantitative description of the responses of the MAT-LyLu cells to direct current (dc) electric fields (EFs) of physiological strength (0.3-3 V/cm); and (3) voltage and time dependency of the cells' responses to the dcEFs. These issues were studied by application of statistical and fractal analyses of the cells' trajectories. The results showed that the MAT-LyLu cells responded strongly to the applied dcEFs by migrating towards the cathode. On the other hand, the galvanotactic response of the AT-2 cells was weak and towards the anode. Further studies of the MAT-LyLu cell motility in dcEFs of increasing strength showed that their response consisted of two voltage domains. Weaker fields (approximately 0.6 V/cm) induced "straightening" of the cells' trajectories without the cells showing a clear tendency to move along the applied field. Stronger fields (>0.6 V/cm) made the cells' movement oriented with respect to the direction of the applied field, without further changing the trajectories' structure. The results also showed that the cells do not perform a directed movement instantaneously after switching on a dcEF of 3 V/cm; approximately 30 min lapsed before the cells were able to fully follow the direction of the applied field. Possible biophysical bases and pathophysiological significance of the results obtained are discussed.
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Affiliation(s)
- Zuzanna Siwy
- Institute of Physical Chemistry and Technology of Polymers, Silesian University of Technology, Gliwice, Poland.
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Abstract
We present a synthetic nanodevice, which transports potassium ions against their concentration gradient if stimulated with external field fluctuations. It consists of a single, conical pore, created in a thin polyethylene terephthalate film. The pumping mechanism is similar to one of longitudinally oscillating deterministic ratchets.
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Affiliation(s)
- Z Siwy
- Silesian University of Technology, Strzody 9, 44-100 Gliwice, Poland
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48
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Abstract
The transport characteristics of nanofabricated synthetic pores of similar dimensions to those of biological channels is reported. By comparison of the ion current through single synthetic and biological channels we show that the 1/f(alpha) noise indeed originates from the channel's opening-closing process. Strong evidence has been provided that the latter is related to the underlying motions of channel wall constituents.
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Affiliation(s)
- Z Siwy
- Silesian University of Technology, Strzody 9, 44-100 Gliwice, Poland
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49
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Siwy Z, Ausloos M, Ivanova K. Correlation studies of open and closed state fluctuations in an ion channel: Analysis of ion current through a large-conductance locust potassium channel. Phys Rev E Stat Nonlin Soft Matter Phys 2002; 65:031907. [PMID: 11909109 DOI: 10.1103/physreve.65.031907] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2001] [Indexed: 05/23/2023]
Abstract
Ion current fluctuations occurring within open and closed states of a large-conductance locust potassium channel (BK channel) were investigated for the existence of correlation. Both the time series, extracted from the ion current signal, were studied by the autocorrelation function and the detrended fluctuation analysis (DFA) methods. The persistent character of the short- and middle-range correlations of time series is shown by the slow decay of the autocorrelation function. The DFA exponent alpha is significantly larger than 0.5. The existence of strongly persistent long-range correlations was detected only for closed state fluctuations, with alpha=0.98+/-0.02. The long-range correlation of the BK channel action is therefore determined by the character of closed states. The main outcome of this study reveals that the memory effect is present not only between successive conducting states of the channel but also independently within the open and closed states themselves. As the ion current fluctuations give information about the dynamics of the channel protein, our results point to the correlated character of the protein movement regardless of whether the channel is in its open or closed state.
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Affiliation(s)
- Zuzanna Siwy
- Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, 44-100 Gliwice, Poland.
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Mercik S, Weron K, Siwy Z. Statistical analysis of ionic current fluctuations in membrane channels. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 1999; 60:7343-8. [PMID: 11970679 DOI: 10.1103/physreve.60.7343] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/1999] [Indexed: 11/07/2022]
Abstract
The statistical analysis of an ionic current signal recorded from a single channel of a biological membrane is presented. We find the main characteristics of the ionic current probability density, the closed- and open-state distributions, and the autocorrelation function of the current recordings by using procedures based on the kernel and tail estimators, the bootstrap methodology; and the Zipf plots. The results provide evidence for the non-Markovian character of the channel kinetics of the investigated data.
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Affiliation(s)
- S Mercik
- Institute of Physics, Wroclaw University of Technology, 50-370 Wroclaw, Poland.
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