scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Microsecond time-scale discrimination among polycytidylic acid, polyadenylic acid, and polyuridylic acid as homopolymers or as segments within single RNA molecules.

01 Dec 1999-Biophysical Journal (The Biophysical Society)-Vol. 77, Iss: 6, pp 3227-3233
TL;DR: It is demonstrated that this nanopore behaves as a detector that can rapidly discriminate between pyrimidine and purine segments along an RNA molecule.
About: This article is published in Biophysical Journal.The article was published on 1999-12-01 and is currently open access. It has received 1044 citations till now. The article focuses on the topics: RNA & DNA.
Citations
More filters
Journal ArticleDOI
TL;DR: A nanopore-based device provides single-molecule detection and analytical capabilities that are achieved by electrophoretically driving molecules in solution through a nano-scale pore, a unique analytical capability that makes inexpensive, rapid DNA sequencing a possibility.
Abstract: A nanopore-based device provides single-molecule detection and analytical capabilities that are achieved by electrophoretically driving molecules in solution through a nano-scale pore. The nanopore provides a highly confined space within which single nucleic acid polymers can be analyzed at high throughput by one of a variety of means, and the perfect processivity that can be enforced in a narrow pore ensures that the native order of the nucleobases in a polynucleotide is reflected in the sequence of signals that is detected. Kilobase length polymers (single-stranded genomic DNA or RNA) or small molecules (e.g., nucleosides) can be identified and characterized without amplification or labeling, a unique analytical capability that makes inexpensive, rapid DNA sequencing a possibility. Further research and development to overcome current challenges to nanopore identification of each successive nucleotide in a DNA strand offers the prospect of 'third generation' instruments that will sequence a diploid mammalian genome for ∼$1,000 in ∼24 h.

2,512 citations

Journal ArticleDOI
12 Jul 2001-Nature
TL;DR: A general strategy for the synthesis of highly ordered, rigid arrays of nanoporous carbon having uniform but tunable diameters is described, which gives rise to promising electrocatalytic activity for oxygen reduction and could prove to be practically relevant for fuel-cell technologies.
Abstract: Nanostructured carbon materials are potentially of great technological interest for the development of electronic1,2, catalytic3,4 and hydrogen-storage systems5,6. Here we describe a general strategy for the synthesis of highly ordered, rigid arrays of nanoporous carbon having uniform but tunable diameters (typically 6 nanometres inside and 9 nanometres outside). These structures are formed by using ordered mesoporous silicas as templates, the removal of which leaves a partially ordered graphitic framework. The resulting material supports a high dispersion of platinum nanoparticles, exceeding that of other common microporous carbon materials (such as carbon black, charcoal and activated carbon fibres). The platinum cluster diameter can be controlled to below 3 nanometres, and the high dispersion of these metal clusters gives rise to promising electrocatalytic activity for oxygen reduction, which could prove to be practically relevant for fuel-cell technologies. These nanomaterials can also be prepared in the form of free-standing films by using ordered silica films as the templates.

2,352 citations

Journal ArticleDOI
TL;DR: The solid-state nanopore proves to be a surprisingly versatile new single-molecule tool for biophysics and biotechnology.
Abstract: The passage of individual molecules through nanosized pores in membranes is central to many processes in biology. Previously, experiments have been restricted to naturally occurring nanopores, but advances in technology now allow artificial solid-state nanopores to be fabricated in insulating membranes. By monitoring ion currents and forces as molecules pass through a solid-state nanopore, it is possible to investigate a wide range of phenomena involving DNA, RNA and proteins. The solid-state nanopore proves to be a surprisingly versatile new single-molecule tool for biophysics and biotechnology.

1,861 citations

Journal ArticleDOI
12 Jul 2001-Nature
TL;DR: It is shown that ion-beam sculpting can be used to fashion an analogous solid-state device: a robust electronic detector consisting of a single nanopore in a Si3N4 membrane, capable of registering single DNA molecules in aqueous solution.
Abstract: Manipulating matter at the nanometre scale is important for many electronic, chemical and biological advances, but present solid-state fabrication methods do not reproducibly achieve dimensional control at the nanometre scale. Here we report a means of fashioning matter at these dimensions that uses low-energy ion beams and reveals surprising atomic transport phenomena that occur in a variety of materials and geometries. The method is implemented in a feedback-controlled sputtering system that provides fine control over ion beam exposure and sample temperature. We call the method "ion-beam sculpting", and apply it to the problem of fabricating a molecular-scale hole, or nanopore, in a thin insulating solid-state membrane. Such pores can serve to localize molecular-scale electrical junctions and switches and function as masks to create other small-scale structures. Nanopores also function as membrane channels in all living systems, where they serve as extremely sensitive electro-mechanical devices that regulate electric potential, ionic flow, and molecular transport across cellular membranes. We show that ion-beam sculpting can be used to fashion an analogous solid-state device: a robust electronic detector consisting of a single nanopore in a Si3N4 membrane, capable of registering single DNA molecules in aqueous solution.

1,597 citations

Journal ArticleDOI
TL;DR: This article reviews the use of nanopore technology in DNA sequencing, genetics and medical diagnostics and suggests that nanopore-based sensors could be competitive with other third-generation DNA sequencing technologies.
Abstract: Nanopore analysis is an emerging technique that involves using a voltage to drive molecules through a nanoscale pore in a membrane between two electrolytes, and monitoring how the ionic current through the nanopore changes as single molecules pass through it. This approach allows charged polymers (including single-stranded DNA, double-stranded DNA and RNA) to be analysed with subnanometre resolution and without the need for labels or amplification. Recent advances suggest that nanopore-based sensors could be competitive with other third-generation DNA sequencing technologies, and may be able to rapidly and reliably sequence the human genome for under $1,000. In this article we review the use of nanopore technology in DNA sequencing, genetics and medical diagnostics.

1,299 citations

References
More filters
Journal ArticleDOI
TL;DR: It is shown that an electric field can drive single-stranded RNA and DNA molecules through a 2.6-nm diameter ion channel in a lipid bilayer membrane, which could in principle provide direct, high-speed detection of the sequence of bases in single molecules of DNA or RNA.
Abstract: We show that an electric field can drive single-stranded RNA and DNA molecules through a 2.6-nm diameter ion channel in a lipid bilayer membrane. Because the channel diameter can accommodate only a single strand of RNA or DNA, each polymer traverses the membrane as an extended chain that partially blocks the channel. The passage of each molecule is detected as a transient decrease of ionic current whose duration is proportional to polymer length. Channel blockades can therefore be used to measure polynucleotide length. With further improvements, the method could in principle provide direct, high-speed detection of the sequence of bases in single molecules of DNA or RNA.

3,251 citations

Journal ArticleDOI
13 Dec 1996-Science
TL;DR: The structure proves the heptameric subunit stoichiometry of the α-hemolysin oligomer, shows that a glycine-rich and solvent-exposed region of a water-soluble protein can self-assemble to form a transmembrane pore of defined structure, and provides insight into the principles of membrane interaction and transport activity of β barrel pore-forming toxins.
Abstract: The structure of the Staphylococcus aureus α-hemolysin pore has been determined to 1.9 A resolution. Contained within the mushroom-shaped homo-oligomeric heptamer is a solvent-filled channel, 100 A in length, that runs along the sevenfold axis and ranges from 14 A to 46 A in diameter. The lytic, transmembrane domain comprises the lower half of a 14-strand antiparallel β barrel, to which each protomer contributes two β strands, each 65 A long. The interior of the β barrel is primarily hydrophilic, and the exterior has a hydrophobic belt 28 A wide. The structure proves the heptameric subunit stoichiometry of the α-hemolysin oligomer, shows that a glycine-rich and solvent-exposed region of a water-soluble protein can self-assemble to form a transmembrane pore of defined structure, and provides insight into the principles of membrane interaction and transport activity of β barrel pore-forming toxins.

2,238 citations

Journal ArticleDOI
28 Jul 1994-Nature
TL;DR: This work shows that natural channel-forming peptides incorporated into a bilayer lipid membrane can be used to detect the passage of single molecules with gyration radii as small as 5–15 Å, and infer both the average number and the diffusion coefficients of poly(ethylene glycol) molecules in the pore.
Abstract: The change in conductance of a small electrolyte-filled capillary owing to the passage of sub-micrometre-sized particles has long been used for particle counting and sizing. A commercial device for such measurements, the Coulter counter, is able to detect particles of sizes down to several tenths of a micrometre. Nuclepore technology (in which pores are etched particle tracks) has extended the lower limit of size detection to 60-nm particles by using a capillary of diameter 0.45 micron (ref. 4). Here we show that natural channel-forming peptides incorporated into a bilayer lipid membrane can be used to detect the passage of single molecules with gyration radii as small as 5-15 A. From our experiments with alamethicin pores we infer both the average number and the diffusion coefficients of poly(ethylene glycol) molecules in the pore. Our approach provides a means of observing the statistics and mechanics of flexible polymers moving within the confines of precisely defined single-molecule structures.

418 citations


"Microsecond time-scale discriminati..." refers background in this paper

  • ...Previous reports have shown that channel conductance can be used to detect the presence of macromolecules in a channel pore ( Bezrukov et al., 1994, 1996; Bustamante et al., 1995; Kasianowicz et al., 1996)....

    [...]

  • ...Previous reports have shown that channel conductance can be used to detect the presence of macromolecules in a channel pore (Bezrukov et al., 1994, 1996; Bustamante et al., 1995; Kasianowicz et al., 1996)....

    [...]

Journal ArticleDOI
TL;DR: The stability and structural properties of oligomers and the high polymer of adenylic acid were measured, using circular dichroism and absorption spectroscopy as the principal methods, which indicate that poly A and oligo A exist in a single-strand conformation stabilized by base stacking.

353 citations

Journal ArticleDOI
TL;DR: In this article, the thermodynamic and kinetic properties of different sized polymers within their confines were investigated. But the authors focused on the dynamics of different sizes of polymers in the nanoscale pores.
Abstract: Membrane-bound proteinaceous nanoscale pores allow us to simultaneously observe the thermodynamic and kinetic properties of differently sized polymers within their confines. We determine the dynami...

274 citations