Ionic Transport through Chemically Functionalized Hydrogen Peroxide-Sensitive Asymmetric Nanopores

Ali, Mubarak; Ahmed, Ishtiaq; Nasir, Saima; Ramı́rez, Patricio; Niemeyer, Christof M.; Mafé, Salvador; Ensinger, Wolfgang

doi:10.1021/acsami.5b06015

Cited by 47 publications

(37 citation statements)

References 30 publications

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“…Surface charge is an essential feature of nanopores with which selectivity and conduction properties of the pore can be influenced [3,53,54,55,56,57]. Surface charge can be manipulated by chemical modifications [58,59,60,61,62], adding components that bind selectively to functional molecules (sensing) [63,60,38,39], or by applying voltage at embedded electrodes [64,7,65,29,8,9,66]. Different charge patterns allow different functions of the nanopore.…”

Section: Introductionmentioning

confidence: 99%

Multiscale analysis of the effect of surface charge pattern on a nanopore’s rectification and selectivity properties: From all-atom model to Poisson-Nernst-Planck

Valiskó

Matejczyk

Ható

et al. 2019

The Journal of Chemical Physics

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We report a multiscale modeling study for charged cylindrical nanopores using three modeling levels that include (1) an all-atom explicit-water model studied with molecular dynamics (MD), and reduced models with implicit water containing (2) hard-sphere ions studied with the Local Equilibrium Monte Carlo simulation method (computing ionic correlations accurately), and (3) point ions studied with Poisson-Nernst-Planck (PNP) theory (mean-field approximation). We show that reduced models are able to reproduce device functions (rectification and selectivity) for a wide variety of charge patterns; that is, reduced models are useful in understanding the mesoscale physics of the device (i.e., how the current is produced). We also analyze the relationship of the reduced implicit-water models with the explicit-water model and show that diffusion coefficients in the reduced models can be used as adjustable parameters with which the results of the explicit-and implicit-water models can be related. We find that the values of the diffusion coefficients are sensitive to the net charge of the pore, but are relatively transferable to different voltages and charge patterns with the same total charge. Multiscale analysis of the effect of surface charge pattern on a nanopore's rectification and selectivity properties: from all-atom model to Poisson-Nernst-Planck -4/15

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Section: Introductionmentioning

confidence: 99%

Multiscale analysis of the effect of surface charge pattern on a nanopore’s rectification and selectivity properties: From all-atom model to Poisson-Nernst-Planck

Valiskó

Matejczyk

Ható

et al. 2019

The Journal of Chemical Physics

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“…with boronic acid [8], aptamers [9], or based on metal ionprotein interaction [10], and with enzymatic reactions, e.g. for hydrogen peroxide sensing [11,12].…”

Section: Polyimide Membranementioning

confidence: 99%

iNAPO - Ion Conducting Nanopores in Polymer Foils Chemically Modified for Biomolecular Sensing

Ensinger¹,

Thiel²,

Duznovic³

et al. 2016

Proceedings of the World Congress on Recent Advances in Nanotechnology

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In the present biomimetic approach, ion-conducting nanopores are fabricated in polymer foils and are chemically modified so that they can be used as the core of a biomolecular sensing system. The basic principles of fabrication and working mechanism of these nanosensors is described. Polyimide foils are irradiated at the heavy ion accelerator at GSI Helmholtz-Center in Darmstadt with a single ion of a heavy element such as gold. The ion is at such a high speed that it penetrates through the membrane in a straight line, forming a so-called latent ion damage track. This track is converted into a single conical nanopore via asymmetric chemical etching, with its smaller aperture being in the range of a few nanometers. At the surface of the nanopore a biorecognition unit (ligand) is immobilized which specifically fit to another molecule (receptor) to be analysed. Only with these analyte molecules recognition unit do react in a keylock principle. For sensing, the polymer foil with the nanopore is placed into an electrochemical cell with two compartments, with the foil acting as separation membrane. Each compartment contains an electrode dipped in electrolyte (potassium chloride) solution. When a potential is applied, an electric current flows through the nanopores. If analyte molecules (receptor) are present, they react with the immobilized ligand at the nanopore walls via specific ligand-receptor interaction, thus changing the transmembrane electrolyte current. Thus, the set-up works as a highly sensitive and specific nanosensor. Fabrication and working principle of this type of nanosensor is described. As an example, results on quantitative sensing of a protein are shown. As an outlook for development and application of this sensing principle, the iNAPO-project will be presented, run by a group of materials scientists, biologists, chemists, physicist and electrical engineers with the aim of creating new types of sensors based on bioinspired ion conducting nanopores.

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“…In this extended study, we examine various asymmetric nanopore designs thus gaining an additional device function to detect the effect of the X + ions thus gaining a dual responsive device. This device function is rectification that appears when the nanopore is asymmetric in its structural features [16,17,18,19,20,21], such as its charge pattern (e.g., bipolar nanopores) or geometry (e.g., conical nanopores). Rectification is defined as the ratio of current magnitudes in the ON (forward biased) and OFF (reversed biased) states taken at the two opposite signs of a given voltage, |I(U)/I(−U)|, where |I(U)| > |I(−U)|.…”

Section: Introductionmentioning

confidence: 99%

The effect of the charge pattern on the applicability of a nanopore as a sensor

Mádai

Valiskó

Boda

2019

Journal of Molecular Liquids

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We investigate a model nanopore sensor that is able to detect analyte ions that are present in the electrolyte solution in very small concentrations. The nanopore selectively binds the analyte ions with which the local concentrations of the ions of the background electrolyte (KCl), and, thus, the ionic current flowing through the pore is changed. Analyte concentration can be determined from calibration curves. In our previous study (Mádai et al. J. Chem. Phys., 147(24):244702, 2017.), we proposed a symmetric model (surface charge is negative all along the pore). The mechanism of sensing was a competition between K + and positive analyte ions, so increasing analyte concentration decreased K + current. Here we allow asymmetric charge patterns on the pore wall (positive/negative/neutral along the pore), thus, gaining an additional device function, rectification, resulting in a dual responsive device. We find that a bipolar nanopore is an efficient geometry with Cl − ions being the main charge carriers. The mechanism of sensing is that more positive analyte ions attract more Cl − ions into the pore thus increasing the current. Also they make the pore less asymmetric and, thus, decrease rectification. We use a hybrid computer simulation method, where a generalization of the grand canonical Monte Carlo method to non-equilibrium (Local Equilibrium Monte Carlo) is coupled to the Nernst-Planck equation with which the flux is computed.

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Ionic Transport through Chemically Functionalized Hydrogen Peroxide-Sensitive Asymmetric Nanopores

Cited by 47 publications

References 30 publications

Multiscale analysis of the effect of surface charge pattern on a nanopore’s rectification and selectivity properties: From all-atom model to Poisson-Nernst-Planck

Multiscale analysis of the effect of surface charge pattern on a nanopore’s rectification and selectivity properties: From all-atom model to Poisson-Nernst-Planck

iNAPO - Ion Conducting Nanopores in Polymer Foils Chemically Modified for Biomolecular Sensing

The effect of the charge pattern on the applicability of a nanopore as a sensor

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