Solid-state nanopore channels with DNA selectivity

Iqbal, Samir M.; Akin, Demir; Bashir, Rashid

doi:10.1038/nnano.2007.78

Cited by 377 publications

(378 citation statements)

References 24 publications

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“…As recently demonstrated [70], binding of a purified subunit of the nuclear pore complex allowed for the functionality and thus translocation control to be mimicked. Other groups used this idea to detect the sequence of DNA by binding either DNA [71,72] or peptide nucleic acid (PNA) [73] to the interior of solid-state nanopores. Alternatively, the transport of ions through nanopores can be controlled by adding temperaturedependent polymers to the nanopore walls [74].…”

Section: Solid-state Nanoporesmentioning

confidence: 99%

Controlling molecular transport through nanopores

Keyser

2011

J. R. Soc. Interface.

172

191

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Nanopores are emerging as powerful tools for the detection and identification of macromolecules in aqueous solution. In this review, we discuss the recent development of active and passive controls over molecular transport through nanopores with emphasis on biosensing applications. We give an overview of the solutions developed to enhance the sensitivity and specificity of the resistive-pulse technique based on biological and solid-state nanopores.

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Section: Solid-state Nanoporesmentioning

confidence: 99%

Controlling molecular transport through nanopores

Keyser

2011

J. R. Soc. Interface.

172

191

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“…The amplitude and direction of the current shift can depend on the electrolyte concentration, indicating that the electrostatic charge and the pore blockage influence the current and translocation (17). The translocation time and current shift also depend on interactions with the pore walls, and such devices have been shown to detect base-pair mismatches in ssDNA modified pores (15).…”

Section: Nano-scale Detection Of Nucleic Acidsmentioning

confidence: 99%

Electrochemical Characterization of Regularly-Aligned Nanopore Array Membranes Filled with Electrolyte Solutions and Their Use for Detection of Nucleic Acid Hybridization

et al. 2011

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We report on the electrochemical characterization of regularlyaligned cylindrical nanopore arrays supported in silicon nitride membranes and preliminary results for the detection of nucleic acid hybridization on the nanopore walls. A range of nanopore arrays with diameters between 40 and 150 nm were examined. We tested the effect of pore diameter, number of pores, electrolyte concentration and surface chemistry on the conductance of the nanopore membranes. The pores were functionalized with singlestranded DNA and conductance measurements were performed before and after hybridization. In many cases, changes in current rectification were observed following hybridization, which is discussed as a strategy for nucleic acid hybridization and interactions. IntroductionNanopore electrochemistry has received significant attention in recent years as a technique for the detection of biochemical interactions (1). Measurements of biochemical events in nano-scale confinement offer a number of advantages over conventional bulk techniques. These include i) faster response times and shorter diffusion lengths due to the increased surface-to-volume ratios, ii) improved control of molecular transport through manipulation of the electrical double layer, iii) a move towards single-molecule biosensing, and iv) the ability to probe interactions on biologically relevant length scales. Additionally, recent advances in micro-and nano-fabrication techniques have improved the reproducibility of making such nano-scale detection systems.Electrochemical measurements are performed within nano-scale channels, typically supported within thin membranes. These can include single channels or arrays of channels. In the typical setup, the channel is filled with an electrolyte solution and a potential is applied across the membrane. Geometric and surface properties of the channels can be determined from conductance measurements, and a variety of techniques can be used to detect biochemical interactions within the pores.To explore the use of arrayed nanopore membranes in biosensing, we present preliminary results for i) the characterization of nanopore array membranes using conductance measurements, and ii) electrochemical detection of nucleic acid hybridization at functionalized pore walls. Conductance measurements were performed on nanopore membranes in potassium chloride electrolyte over a broad range of ionic strengths. A variety of pore diameters, array sizes and surface treatments are tested, including biochemical functionalization with single-stranded DNA (ssDNA). Then, the effects of solution-based nucleic acids on the conductance of the nanopore membranes were measured for both untreated and nucleic acid-functionalized nanopores. In certain cases, current rectification behavior was observed, which is characterized by nonlinearity of the current-potential curve. Rectification has been attributed to asymmetric geometry and charge distributions on the device surface (2,3), and has been proposed as a method to detect biochemical interactions on the...

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“…Transport through channels and pores has been recently proposed as a method for separating molecular mixtures. Several artificial molecular pore systems, which behave similarly to biological channels, have been developed and successfully tested [4][5][6][7][8][9]. The main idea of this method is to mimic biological systems where very efficient, fast and robust separations are achieved on a large scale in many cellular systems [3].…”

Section: Introductionmentioning

confidence: 99%

Theoretical analysis of selectivity mechanisms in molecular transport through channels and nanopores

Agah

Pasquali

Kolomeisky

2015

The Journal of Chemical Physics

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Selectivity is one of the most fundamental concepts in natural sciences, and it is also critically important in various technological, industrial and medical applications. Although there are many experimental methods that allow to separate molecules, frequently they are expensive and not efficient. Recently, a new method of separation of chemical mixtures based on utilization of channels and nanopores has been proposed and successfully tested in several systems. However, mechanisms of selectivity in the molecular transport during the translocation are still not well understood. Here we develop a simple theoretical approach to explain the origin of selectivity in molecular fluxes through channels. Our method utilizes discrete-state stochastic models that take into account all relevant chemical transitions and can be solved analytically. More specifically, we analyze channels with one and two binding sites employed for separating mixtures of two types of molecules. The effects of the symmetry and the strength of the molecular-pore interactions are examined. It is found that for one-site binding channels the differences in the strength of interactions for two species drive the separation. At the same time, in more realistic two-site systems the symmetry of interaction potential becomes also important. The most efficient separation is predicted when the specific binding site is located near the entrance to the nanopore. In addition, the selectivity is higher for large entrance rates into the the channel. It is also found that the molecular transport is more selective for repulsive interactions than for attractive interactions. The physical-chemical origin of the observed phenomena are discussed.

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Solid-state nanopore channels with DNA selectivity

Cited by 377 publications

References 24 publications

Controlling molecular transport through nanopores

Controlling molecular transport through nanopores

Electrochemical Characterization of Regularly-Aligned Nanopore Array Membranes Filled with Electrolyte Solutions and Their Use for Detection of Nucleic Acid Hybridization

Theoretical analysis of selectivity mechanisms in molecular transport through channels and nanopores

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