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Pyo K, Matus MF, Malola S, Hulkko E, Alaranta J, Lahtinen T, Häkkinen H, Pettersson M. Tailoring the interaction between a gold nanocluster and a fluorescent dye by cluster size: creating a toolbox of range-adjustable pH sensors. NANOSCALE ADVANCES 2022; 4:4579-4588. [PMID: 36425249 PMCID: PMC9606730 DOI: 10.1039/d2na00487a] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
We present a novel strategy for tailoring the fluorescent azadioxatriangulenium (KU) dye-based pH sensor to the target pH range by regulating the pK a value of the gold nanoclusters. Based on the correlation between the pK a and surface curvature of ligand-protected nanoparticles, the pK a value of the gold nanoclusters was controlled by size. In particular, three different-sized para-mercaptobenzoic acid (p-MBA) protected gold nanoclusters, Au25(p-MBA)18, Au102(p-MBA)44, and Au210-230(p-MBA)70-80 were used as the regulator for the pH range of the KU response. The negatively charged gold nanoclusters enabled the positively charged KU to bind to the surface, forming a complex and quenching the fluorescence of the KU by the energy transfer process. The fluorescence was restored after adjusting the surface charge of the gold nanocluster by controlling the solution pH. In addition, the KU exhibited a significantly different pH response behaviour for each gold nanocluster. Au210-230(p-MBA)70-80 showed a higher pH response range than Au102(p-MBA)44, which was intuitive. However, Au25(p-MBA)18 showed an unexpectedly high pH response behaviour. pK a titration measurement, molecular dynamics simulations, and essential dynamics analysis showed that small nanoclusters do not follow the scaling between the curvature and the pK a value. Instead, the behaviour is governed by the distribution and interaction of p-MBA ligands on the nanocluster surface. This work presents an effective design strategy for fabricating a range adjustable pH sensor by understanding the protonation behaviour of the ultrasmall gold nanoclusters in an atomic range.
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Affiliation(s)
- Kyunglim Pyo
- Department of Chemistry, Nanoscience Centre, University of Jyväskylä P. O. Box 35 FI-40014 Finland
| | - María Francisca Matus
- Department of Physics, Nanoscience Centre, University of Jyväskylä P. O. Box 35 FI-40014 Finland
| | - Sami Malola
- Department of Physics, Nanoscience Centre, University of Jyväskylä P. O. Box 35 FI-40014 Finland
| | - Eero Hulkko
- Department of Chemistry, Nanoscience Centre, University of Jyväskylä P. O. Box 35 FI-40014 Finland
| | - Johanna Alaranta
- Department of Chemistry, Nanoscience Centre, University of Jyväskylä P. O. Box 35 FI-40014 Finland
| | - Tanja Lahtinen
- Department of Chemistry, Nanoscience Centre, University of Jyväskylä P. O. Box 35 FI-40014 Finland
| | - Hannu Häkkinen
- Department of Chemistry, Nanoscience Centre, University of Jyväskylä P. O. Box 35 FI-40014 Finland
- Department of Physics, Nanoscience Centre, University of Jyväskylä P. O. Box 35 FI-40014 Finland
| | - Mika Pettersson
- Department of Chemistry, Nanoscience Centre, University of Jyväskylä P. O. Box 35 FI-40014 Finland
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Gopmandal PP, Duval JF. Electrostatics and electrophoresis of engineered nanoparticles and particulate environmental contaminants: beyond zeta potential-based formulation. Curr Opin Colloid Interface Sci 2022. [DOI: 10.1016/j.cocis.2022.101605] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Apel PY, Velizarov S, Volkov AV, Eliseeva TV, Nikonenko VV, Parshina AV, Pismenskaya ND, Popov KI, Yaroslavtsev AB. Fouling and Membrane Degradation in Electromembrane and Baromembrane Processes. MEMBRANES AND MEMBRANE TECHNOLOGIES 2022. [DOI: 10.1134/s2517751622020032] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Dammak L, Fouilloux J, Bdiri M, Larchet C, Renard E, Baklouti L, Sarapulova V, Kozmai A, Pismenskaya N. A Review on Ion-Exchange Membrane Fouling during the Electrodialysis Process in the Food Industry, Part 1: Types, Effects, Characterization Methods, Fouling Mechanisms and Interactions. MEMBRANES 2021; 11:789. [PMID: 34677555 PMCID: PMC8539029 DOI: 10.3390/membranes11100789] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 10/05/2021] [Accepted: 10/11/2021] [Indexed: 11/16/2022]
Abstract
Electrodialysis (ED) was first established for water desalination and is still highly recommended in this field for its high water recovery, long lifetime and acceptable electricity consumption. Today, thanks to technological progress in ED processes and the emergence of new ion-exchange membranes (IEMs), ED has been extended to many other applications in the food industry. This expansion of uses has also generated several problems such as IEMs' lifetime limitation due to different ageing phenomena (because of organic and/or mineral compounds). The current commercial IEMs show excellent performance in ED processes; however, organic foulants such as proteins, surfactants, polyphenols or other natural organic matters can adhere on their surface (especially when using anion-exchange membranes: AEMs) forming a colloid layer or can infiltrate the membrane matrix, which leads to the increase in electrical resistance, resulting in higher energy consumption, lower water recovery, loss of membrane permselectivity and current efficiency as well as lifetime limitation. If these aspects are not sufficiently controlled and mastered, the use and the efficiency of ED processes will be limited since, it will no longer be competitive or profitable compared to other separation methods. In this work we reviewed a significant amount of recent scientific publications, research and reviews studying the phenomena of IEM fouling during the ED process in food industry with a special focus on the last decade. We first classified the different types of fouling according to the most commonly used classifications. Then, the fouling effects, the characterization methods and techniques as well as the different fouling mechanisms and interactions as well as their influence on IEM matrix and fixed groups were presented, analyzed, discussed and illustrated.
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Affiliation(s)
- Lasâad Dammak
- Institut de Chimie et des Matériaux Paris-Est (ICMPE), Université Paris-Est Créteil, CNRS, ICMPE, UMR 7182, 2 Rue Henri Dunant, 94320 Thiais, France; (J.F.); (M.B.); (C.L.); (E.R.)
| | - Julie Fouilloux
- Institut de Chimie et des Matériaux Paris-Est (ICMPE), Université Paris-Est Créteil, CNRS, ICMPE, UMR 7182, 2 Rue Henri Dunant, 94320 Thiais, France; (J.F.); (M.B.); (C.L.); (E.R.)
| | - Myriam Bdiri
- Institut de Chimie et des Matériaux Paris-Est (ICMPE), Université Paris-Est Créteil, CNRS, ICMPE, UMR 7182, 2 Rue Henri Dunant, 94320 Thiais, France; (J.F.); (M.B.); (C.L.); (E.R.)
| | - Christian Larchet
- Institut de Chimie et des Matériaux Paris-Est (ICMPE), Université Paris-Est Créteil, CNRS, ICMPE, UMR 7182, 2 Rue Henri Dunant, 94320 Thiais, France; (J.F.); (M.B.); (C.L.); (E.R.)
| | - Estelle Renard
- Institut de Chimie et des Matériaux Paris-Est (ICMPE), Université Paris-Est Créteil, CNRS, ICMPE, UMR 7182, 2 Rue Henri Dunant, 94320 Thiais, France; (J.F.); (M.B.); (C.L.); (E.R.)
| | - Lassaad Baklouti
- Department of Chemistry, College of Sciences and Arts at Al Rass, Qassim University, Ar Rass 51921, Saudi Arabia;
| | - Veronika Sarapulova
- Department of Physical Chemistry, Kuban State University, 149, Stavropol’skaya Str., 350040 Krasnodar, Russia; (V.S.); (A.K.); (N.P.)
| | - Anton Kozmai
- Department of Physical Chemistry, Kuban State University, 149, Stavropol’skaya Str., 350040 Krasnodar, Russia; (V.S.); (A.K.); (N.P.)
| | - Natalia Pismenskaya
- Department of Physical Chemistry, Kuban State University, 149, Stavropol’skaya Str., 350040 Krasnodar, Russia; (V.S.); (A.K.); (N.P.)
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Pismenskaya N, Sarapulova V, Klevtsova A, Mikhaylin S, Bazinet L. Adsorption of Anthocyanins by Cation and Anion Exchange Resins with Aromatic and Aliphatic Polymer Matrices. Int J Mol Sci 2020; 21:ijms21217874. [PMID: 33114195 PMCID: PMC7660631 DOI: 10.3390/ijms21217874] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 10/19/2020] [Accepted: 10/20/2020] [Indexed: 01/06/2023] Open
Abstract
This study examines the mechanisms of adsorption of anthocyanins from model aqueous solutions at pH values of 3, 6, and 9 by ion-exchange resins making the main component of heterogeneous ion-exchange membranes. This is the first report demonstrating that the pH of the internal solution of a KU-2-8 aromatic cation-exchange resin is 2-3 units lower than the pH of the external bathing anthocyanin-containing solution, and the pH of the internal solution of some anion-exchange resins with an aromatic (AV-17-8, AV-17-2P) or aliphatic (EDE-10P) matrix is 2-4 units higher than the pH of the external solution. This pH shift is caused by the Donnan exclusion of hydroxyl ions (in the KU-2-8 resin) or protons (in the AV-17-8, AV-17-2P, and EDE-10P resins). The most significant pH shift is observed for the EDE-10P resin, which has the highest ion-exchange capacity causing the highest Donnan exclusion. Due to the pH shift, the electric charge of anthocyanin inside an ion-exchange resin differs from its charge in the external solution. At pH 6, the external solution contains uncharged anthocyanin molecules. However, in the AV-17-8 and AV-17-2P resins, the anthocyanins are present as singly charged anions, while in the EDE-10P resin, they are in the form of doubly charged anions. Due to the electrostatic interactions of these anions with the positively charged fixed groups of anion-exchange resins, the adsorption capacities of AV-17-8, AV-17-2P, and EDE-10P were higher than expected. It was established that the electrostatic interactions of anthocyanins with the charged fixed groups increase the adsorption capacity of the aromatic resin by a factor of 1.8-2.5 compared to the adsorption caused by the π-π (stacking) interactions. These results provide new insights into the fouling mechanism of ion-exchange materials by polyphenols; they can help develop strategies for membrane cleaning and for extracting anthocyanins from juices and wine using ion-exchange resins and membranes.
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Affiliation(s)
- Natalia Pismenskaya
- Kuban State University, 149 Stavropolskaya st., 350040 Krasnodar, Russia; (V.S.); (A.K.)
- Correspondence: ; Tel.: +7-918-48-91-292
| | - Veronika Sarapulova
- Kuban State University, 149 Stavropolskaya st., 350040 Krasnodar, Russia; (V.S.); (A.K.)
| | - Anastasia Klevtsova
- Kuban State University, 149 Stavropolskaya st., 350040 Krasnodar, Russia; (V.S.); (A.K.)
| | - Sergey Mikhaylin
- Department of Food Sciences, Institute of Nutrition and Functional Foods (INAF), Laboratory of Food Processing and ElectroMembrane Process (LTAPEM), University Laval, Québec, QC G1V, Canada; (S.M.); (L.B.)
| | - Laurent Bazinet
- Department of Food Sciences, Institute of Nutrition and Functional Foods (INAF), Laboratory of Food Processing and ElectroMembrane Process (LTAPEM), University Laval, Québec, QC G1V, Canada; (S.M.); (L.B.)
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Karakhim SO, Zhuk PF, Kosterin SO. Kinetics simulation of transmembrane transport of ions and molecules through a semipermeable membrane. J Bioenerg Biomembr 2020; 52:47-60. [PMID: 31933026 DOI: 10.1007/s10863-019-09821-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 12/16/2019] [Indexed: 11/26/2022]
Abstract
We have developed a model to study the kinetics of the redistribution of ions and molecules through a semipermeable membrane in complex mixtures of substances penetrating and nonpenetrating through a membrane. It takes into account the degree of dissociation of these substances, their initial concentrations in solutions separated by a membrane, and volumes of these solutions. The model is based on the assumption that only uncharged particles (molecules or ion pairs) diffuse through a membrane (and not ions as in the Donnan model). The developed model makes it possible to calculate the temporal dependencies of concentrations for all processing ions and molecules at system transition from the initial state to equilibrium. Under equilibrium conditions, the ratio of ion concentrations in solutions separated by a membrane obeys the Donnan distribution. The Donnan effect is the result of three factors: equality of equilibrium concentrations of penetrating molecules on each side of a membrane, dissociation of molecules into ions, and Le Chatelier's principle. It is shown that the Donnan distribution (irregularity of ion distribution) and accordingly absolute value of the Donnan membrane potential increases if: (i) the nonpenetrating salt concentration (in one of the solutions) and its dissociation constant increases, (ii) the total penetrating salt concentration and its dissociation constant decreases, and (iii) the volumes ratio increases (between solutions with and without a nonpenetrating substance). It is shown also that only a slight difference between the degrees of dissociation of two substances can be used for their membrane separation.
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Affiliation(s)
- S O Karakhim
- Palladin Institute of Biochemistry of the National Academy of Sciences of Ukraine, Kyiv, Ukraine.
| | - P F Zhuk
- National Aviation University, Kyiv, Ukraine
| | - S O Kosterin
- Palladin Institute of Biochemistry of the National Academy of Sciences of Ukraine, Kyiv, Ukraine
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Belashova E, Pismenskaya N, Nikonenko V, Sistat P, Pourcelly G. Current-voltage characteristic of anion-exchange membrane in monosodium phosphate solution. Modelling and experiment. J Memb Sci 2017. [DOI: 10.1016/j.memsci.2017.08.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Sarapulova V, Nevakshenova E, Pismenskaya N, Dammak L, Nikonenko V. Unusual concentration dependence of ion-exchange membrane conductivity in ampholyte-containing solutions: Effect of ampholyte nature. J Memb Sci 2015. [DOI: 10.1016/j.memsci.2015.01.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Ali M, Nasir S, Ramirez P, Cervera J, Mafe S, Ensinger W. Calcium binding and ionic conduction in single conical nanopores with polyacid chains: model and experiments. ACS NANO 2012; 6:9247-9257. [PMID: 22978291 DOI: 10.1021/nn303669g] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Calcium binding to fixed charge groups confined over nanoscale regions is relevant to ion equilibrium and transport in the ionic channels of the cell membranes and artificial nanopores. We present an experimental and theoretical description of the dissociation equilibrium and transport in a single conical nanopore functionalized with pH-sensitive carboxylic acid groups and phosphonic acid chains. Different phenomena are simultaneously present in this basic problem of physical and biophysical chemistry: (i) the divalent nature of the phosphonic acid groups fixed to the pore walls and the influence of the pH and calcium on the reversible dissociation equilibrium of these groups; (ii) the asymmetry of the fixed charge density; and (iii) the effects of the applied potential difference and calcium concentration on the observed ionic currents. The significant difference between the carboxylate and phosphonate groups with respect to the calcium binding is clearly observed in the corresponding current-voltage (I-V) curves and can be rationalized by using a simple molecular model based on the grand partition function formalism of statistical thermodynamics. The I-V curves of the asymmetric nanopore can be described by the Poisson and Nernst-Planck equations. The results should be of interest for the basic understanding of divalent ion binding and transport in biological ion channels, desalination membranes, and controlled drug release devices.
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Affiliation(s)
- Mubarak Ali
- Department of Material- and Geo-Sciences, Materials Analysis, Technische Universität Darmstadt, D-64287 Darmstadt, Germany.
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Droge S, Goss KU. Effect of sodium and calcium cations on the ion-exchange affinity of organic cations for soil organic matter. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:5894-901. [PMID: 22540998 DOI: 10.1021/es204449r] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Sorption of organic cations to soil organic matter was studied using dynamic column experiments with different compositions of electrolytes in aqueous eluents. The sorption affinity of the tested variety of charged compounds, including primary, secondary, and tertiary amines and quaternary ammonium compounds, all showed the same response to different medium compositions. The sorption affinity to Pahokee peat (i) strongly decreased with increasing electrolyte concentration, up to a factor 250 due to tested electrolyte compositions alone, (ii) was higher in NaCl solutions than in CaCl(2) solutions of similar ionic strength, and (iii) was more sensitive to a decrease in NaCl than to a decrease in CaCl(2), though the selectivity coefficients were not significantly different. For a weak base that was tested in eluent pH either above or below its pK(a), we demonstrated that the sorption affinity of (iv) the neutral base was hardly affected by different electrolyte compositions, comparable to a neutral reference compound, (v) the protonated weak base was strongly affected by different electrolyte compositions, and (vi) the protonated base was in the same range, or stronger, compared to the neutral base. Mass action law equations for ion-exchange reactions predicted similar trends in a qualitative but not in a quantitative way. More complex models are required to fully account for the contributions of ionic interactions to the sorption of organic cations. These results imply that risk assessment models for organic bases should take ion-exchange processes into account when estimating soil sorption coefficients and bioavailability.
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Affiliation(s)
- Steven Droge
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, 04318 Leipzig, Germany.
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M. Cuong N, Ishizaka S, Kitamura N. Donnan Electric Potential Dependence of Intraparticle Diffusion of Malachite Green in Single Cation Exchange Resin Particles: A Laser Trapping-Microspectroscopy Study. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/ajac.2012.33027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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12
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Maity A, Ghosh P, Das T, Dash J, Purkayastha P. Interaction of a new surface sensitive probe compound with anionic surfactants of varying hydrophobic chain length. J Colloid Interface Sci 2011; 364:395-9. [PMID: 21925672 DOI: 10.1016/j.jcis.2011.08.058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 08/23/2011] [Accepted: 08/24/2011] [Indexed: 10/17/2022]
Abstract
The amide derivative of a bis-phenylethynyl compound meta linked to 2,6-pyridine (BPEAP) poses inherent equilibrium between its neutral and zwitterionic forms in the excited state. BPEAP has been found to bind to the surface of anionic micelles instead of penetrating inside. This phenomenon has been exploited to attempt controlling the process of equilibrium using sodium dodecyl sulfate (SDS) at its pre-micellar and near-micellar aggregation concentrations. The anionic surfactant has been found to alter the equilibrium between the said forms of BPEAP depending on its concentration in solution. The process has been further verified by using sodium decyl sulfate (SDeS), which has smaller hydrophobic chain length than SDS as also varies in the critical micellar concentration (CMC) and aggregation number. The binding constant of the probe to the surfactant aggregates varies depending on the extent of surface available to the fluorophore for attachment.
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Affiliation(s)
- Arnab Maity
- Department of Chemical Sciences, Indian Institute of Science Education and Research, Kolkata, Mohanpur Campus, Mohanpur 741252, WB, India
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Bastakoti BP, Guragain S, Yokoyama Y, Yusa SI, Nakashima K. Incorporation and release behavior of amitriptylene in core–shell–corona type triblock copolymer micelles. Colloids Surf B Biointerfaces 2011; 88:734-40. [DOI: 10.1016/j.colsurfb.2011.08.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Revised: 08/01/2011] [Accepted: 08/10/2011] [Indexed: 10/17/2022]
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García-Giménez E, López ML, Aguilella VM, Alcaraz A. Linearity, saturation and blocking in a large multiionic channel: divalent cation modulation of the OmpF porin conductance. Biochem Biophys Res Commun 2010; 404:330-4. [PMID: 21134352 DOI: 10.1016/j.bbrc.2010.11.118] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 11/27/2010] [Indexed: 11/16/2022]
Abstract
Measurement of unitary conductance is a fundamental step in the characterization of a protein ion channel permeabilizing a membrane. We study here the effect of salts of divalent cations on the OmpF channel conductance with a particular emphasis in dissecting the role of the electrolyte itself, the role of the counterion accumulation induced by the protein channel charges and other effects not found in salts of monovalent cations. We show that current saturation and blocking are not exclusive properties of narrow (single-file) ion channels but may be observed in large, multiionic channels like bacterial porins. Single-channel conductance measurements performed over a wide range of salt concentrations (up to 3 M) combined with continuum electrodiffusion calculations demonstrate that current saturation cannot be simply ascribed to ion interaction with protein channel residues.
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Affiliation(s)
- Elena García-Giménez
- Laboratory of Molecular Biophysics, Department of Physics, Universitat Jaume I, Av. Sos Baynat s/n, 12080 Castellón, Spain
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López ML, García-Giménez E, Aguilella VM, Alcaraz A. Critical assessment of OmpF channel selectivity: merging information from different experimental protocols. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:454106. [PMID: 21339594 DOI: 10.1088/0953-8984/22/45/454106] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The ion selectivity of a channel can be quantified in several ways by using different experimental protocols. A wide, mesoscopic channel, the OmpF porin of the outer membrane of E. coli, serves as a case study for comparing and analysing several measures of the channel cation-anion permeability in chlorides of alkali metals (LiCl, NaCl, KCl, CsCl). We show how different insights can be gained and integrated to rationalize the global image of channel selectivity. To this end, reversal potential, channel conductance and bi-ionic potential (two different salts with a common anion on each side of the channel but with the same concentration) experiments are discussed in light of an electrodiffusion model based on the Poisson-Nernst-Planck formalism. Measurements and calculations based on the atomic crystal structure of the channel show that each protocol displays a particular balance between the different sources of selectivity.
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Affiliation(s)
- M L López
- Department of Physics, Laboratory of Molecular Biophysics, Universitat Jaume I, Avenida Sos Baynat s/n, 12080 Castellón, Spain
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García-Giménez E, Alcaraz A, Aguilella VM, Ramírez P. Directional ion selectivity in a biological nanopore with bipolar structure. J Memb Sci 2009. [DOI: 10.1016/j.memsci.2009.01.026] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Hänninen K, Kaukonen AM, Murtomäki L, Hirvonen J. Mechanistic evaluation of factors affecting compound loading into ion-exchange fibers. Eur J Pharm Sci 2007; 31:306-17. [PMID: 17582748 DOI: 10.1016/j.ejps.2007.04.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Revised: 04/25/2007] [Accepted: 04/29/2007] [Indexed: 11/28/2022]
Abstract
Donnan theory was applied to gain mechanistic understanding on the factors affecting drug loading process, compound-fiber affinity and subsequent release from fibrous ion-exchangers. Impact of initial loading solution concentration on fiber occupancy and loading efficiency of compounds were assessed experimentally and theoretically. Relative affinity towards the anion-exchange fibers was studied by dual loading of monovalent salicylic acid and either more lipophilic 3-isopropylsalicylic acid or divalent 5-hydroxyisophthalic acid. The effect of fiber framework on compound binding was evaluated separately for weakly and strongly basic fibers of similar ion-exchange capacities. The results revealed that loading into the ion-exchange fibers can be efficiently adjusted by the concentration of loading solution, leading to improved controllability of drug release from the fiber and minimised drug loss during the loading procedure. Ion-exchange fibers can be utilised successfully in simultaneous delivery of two ionic drugs, which offers a potential drug delivery system for synergistically active drugs. However, physicochemical characteristics of the drug (lipophilicity, valence) and framework of fibrous ion-exchanger affect the relative affinity of the drug towards the fiber, and should not be neglected when selecting appropriate ion-exchange fiber or optimising the external conditions during loading/release. Application of Donnan theory in modelling calculations supported precisely the experimental observations of compound loading (fiber occupancy and loading efficiency).
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Affiliation(s)
- Kaisa Hänninen
- Division of Pharmaceutical Technology, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, FIN-00014 Helsinki, Finland.
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El‐Hag Ali A, El‐Rehiem HAA, Hegazy EA, Ghobashy MM. Characterization and Potential Application of Electro‐Active Acrylamido‐2‐methyl Propane Sulfonic Acid/Acrylic Acid Copolymer Prepared by Ionizing Radiation. JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY 2007. [DOI: 10.1080/10601320601044559] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Tong W, Song H, Gao C, Möhwald H. Equilibrium Distribution of Permeants in Polyelectrolyte Microcapsules Filled with Negatively Charged Polyelectrolyte: The Influence of Ionic Strength and Solvent Polarity. J Phys Chem B 2006; 110:12905-9. [PMID: 16805590 DOI: 10.1021/jp055258w] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The effects of ionic strength and solvent polarity on the equilibrium distribution of fluorescein (FL) and FITC-dextran between the interior of polyelectrolyte multilayer microcapsules filled with negatively charged strong polyelectrolyte and the bulk solution were systematically investigated. A negatively charged strong polyelectrolyte, poly(styrene sulfonate) (PSS), used for CaCO3 core fabrication, was entrapped inside the capsules. Due to the semipermeability of the capsule wall, a Donnan equilibrium between the inner solution within the capsules and the bulk solution was created. The equilibrium distribution of the negatively charged permeants was investigated by means of confocal laser scanning microscopy as a function of ionic strength and solvent polarity. The equilibrium distribution of the negatively charged permeants could be tuned by increasing the bulk ionic strength to decrease the Donnan potential. Decreasing the solvent polarity also could enhance the permeation of FL, which induces a sudden increase of permeation when the ethanol volume fraction was higher than 0.7. This is mainly attributed to the precipitation of PSS. A theoretical model combining the Donnan equilibrium and Manning counterion condensation was employed to discuss the results.
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Affiliation(s)
- Weijun Tong
- Department of Polymer Science and Engineering, and Key Laboratory of Macromolecule Synthesis and Functionalization, Ministry of Education, and The College of Management, Zhejiang University, Hangzhou 310027, China
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