Ionic transport characteristics of negatively and positively charged conical nanopores in 1:1, 2:1, 3:1, 2:2, 1:2, and 1:3 electrolytes

Nasir, Saima; Ali, Mubarak; Cervera, Javier; Gómez, Vicente; Haider, Mustafa; Ensinger, Wolfgang; Mafé, Salvador; Ramı́rez, Patricio

doi:10.1016/j.jcis.2019.06.061

Cited by 21 publications

(15 citation statements)

References 30 publications

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“…3A and Table 1 shows that the channel is cation selective at the smaller Ca 2+ concentrations and anion selective at the higher. We relate this to the so-called "charge inversion", the phenomenon attracting scientists' vivid attention in many disciplines (54)(55)(56)(57). Though it was previously found for a bacterial -barrel porin, OmpF (34,35), now, using reconstituted VDAC as a nanopore sensor we demonstrate this phenomenon for a single polypeptide chainthe C-terminal tail of αSyn, the part of the protein that is responsible for the channel selectivity change (28).…”

Section: Discussionmentioning

confidence: 64%

α-Synuclein emerges as a potent regulator of VDAC-facilitated calcium transport

et al. 2021

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When the Parkinson's disease (PD) related neuronal protein, alpha-synuclein (Syn), is added to the reconstituted mitochondrial voltage-dependent anion channel (VDAC), it reversibly and partially blocks VDAC conductance by its acidic C-terminal tail. Using single-molecule electrophysiology of reconstituted VDAC we now demonstrate that, at CaCl2 concentrations below 150 mM, Syn reverses the channel's selectivity from anionic to cationic. Importantly, we find that the decrease in channel conductance upon its blockage by Syn is hugely overcompensated by a favorable change in the electrostatic environment for calcium, making the blocked state orders-of-magnitude more selective for calcium and thus increasing its net flux. These findings reveal a new regulatory role of Syn, with clear implications for both normal calcium signaling and PD-associated mitochondrial dysfunction.under 17 USC 105 and is also made available for use under a CC0 license.

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Section: Discussionmentioning

confidence: 64%

α-Synuclein emerges as a potent regulator of VDAC-facilitated calcium transport

et al. 2021

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“…Charge inversion also appears in the asymmetric case, as is well known from numerous studies in the last decades. [44,25,10,64,15,47,52] The emphasis, however, was on the case of a negatively charged wall and multivalent cations (the "n" region, in this study). It is well known that the negative surface charge attracts the multivalent cations strongly resulting in an overcharge and in a charge inversion in the second layer.…”

Section: The On Statementioning

confidence: 95%

“…[3,4] and ionic liquids [5]) One can measure phenomena caused by strong ionic correlations in room-temperature aqueous electrolytes (most commonly used in nanofluidic devices) if the electrolyte contains multivalent ions. [6,7,8,9,10,11,12] The most common example is observed when the electrolyte is near a charged wall (a metal electrode or charged groups of an insulator, for example), and the multivalent ions overcharge the wall because they correlate strongly with the surface charge. [13,14,15] Overcharging simply means that more counterions are attracted to the surface than necessary to compensate the surface charge.…”

Section: Introductionmentioning

confidence: 99%

“…Charge inversion causes many experimental phenomena such as the attraction between like-charged particles, [22,23] the reversal of the sign of the electrophoretic mobility [24], or the reversal of the selectivity of nanopores. [25,26,27,8,10] In the latter example, a negatively charged nanopore that is cation selective for KCl becomes anion selective for a 3:1 electrolyte. [25] In that system, the principal device function is selectivity.…”

Section: Introductionmentioning

confidence: 99%

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Rectification of bipolar nanopores in multivalent electrolytes: effect of charge inversion and strong ionic correlations

Fertig

Valiskó

Boda

2020

Phys. Chem. Chem. Phys.

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“…There are various devices with which we can get a detectable signal resulting from these binding events. Ensinger et al [19,20,21,22,36,37] used conical polyethylene terephthalate (PET) nanopores that exhibit rectification due to their asymmetric geometries. When metal ions are bound to the functionalized surfaces thus changing the surface charge pattern on the nanopores' wall, the conduction properties of the pore, including rectification, are changed.…”

Section: Introductionmentioning

confidence: 99%

Application of a bipolar nanopore as a sensor: rectification as an additional device function

Mádai

Valiskó

Boda

2019

Phys. Chem. Chem. Phys.

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We model and simulate a nanopore sensor that selectively binds analyte ions. This binding leads to the modulation of the local concentrations of the ions of the background electrolyte (KCl), and, thus, to the modulation of the ionic current flowing through the pore. The nanopore's wall carries a bipolar charge pattern with a larger positive buffer region determining the anions as the main charge carriers and the smaller negative binding region containing binding sites. This charge pattern proved to be an appropriate one as shown by a previous comparative study of varying charge patterns (Mádai et al. J. Mol. Liq., 2019, 283, 391-398.). Binding of the positive analyte ions attracts more anions in the pore thus increasing the current. The asymmetric nature of the pore results in an additional device function, rectification. Our model, therefore, is a dual response device. Using a reduced model of the nanopore studied by a hybrid computer simulation method (Local Equilibrium Monte Carlo coupled to the Nernst-Planck equation) we show that we can create a sensor whose underlying mechanisms are based on the changes of the local electric field as a response to changing thermodynamic conditions. The change of the electric field results in changes in the local ionic concentrations (depletion zones), and, thus, changes in ionic currents.

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Ionic transport characteristics of negatively and positively charged conical nanopores in 1:1, 2:1, 3:1, 2:2, 1:2, and 1:3 electrolytes

Cited by 21 publications

References 30 publications

α-Synuclein emerges as a potent regulator of VDAC-facilitated calcium transport

α-Synuclein emerges as a potent regulator of VDAC-facilitated calcium transport

Rectification of bipolar nanopores in multivalent electrolytes: effect of charge inversion and strong ionic correlations

Application of a bipolar nanopore as a sensor: rectification as an additional device function

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