1
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Bong JH, Grebenchuk S, Nikolaev KG, Chee CPT, Yang K, Chen S, Baranov D, Woods CR, Andreeva DV, Novoselov KS. Graphene oxide-DNA/graphene oxide-PDDA sandwiched membranes with neuromorphic function. NANOSCALE HORIZONS 2024; 9:863-872. [PMID: 38533738 DOI: 10.1039/d3nh00570d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
The behavior of polyelectrolytes in confined spaces has direct relevance to the protein mediated ion transport in living organisms. In this paper, we govern lithium chloride transport by the interface provided by polyelectrolytes, polycation, poly(diallyldimethylammonium chloride) (PDDA) and, polyanion, double stranded deoxyribonucleic acid (dsDNA), in confined graphene oxide (GO) membranes. Polyelectrolyte-GO interfaces demonstrate neuromorphic functions that were successfully applied with nanochannel ion interactions contributed, resulting in ion memory effects. Excitatory and inhibitory post-synaptic currents were tuned continuously as the number of pulses applied increased accordingly, increasing decay times. Furthermore, we demonstrated the short-term memory of a trained vs untrained device in computation. On account of its simple and safe production along with its robustness and stability, we anticipate our device to be a low dimensional building block for arrays to embed artificial neural networks in hardware for neuromorphic computing. Additionally, incorporating such devices with sensing and actuating parts for a complete feedback loop produces robotics with its own ability to learn by modifying actuation based on sensing data.
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Affiliation(s)
- Jia Hui Bong
- Institute for Functional Intelligent Materials, National University of Singapore, 117544, Singapore.
- Department of Materials Science and Engineering, National University of Singapore, 117575, Singapore
| | - Sergey Grebenchuk
- Institute for Functional Intelligent Materials, National University of Singapore, 117544, Singapore.
- Department of Materials Science and Engineering, National University of Singapore, 117575, Singapore
| | - Konstantin G Nikolaev
- Institute for Functional Intelligent Materials, National University of Singapore, 117544, Singapore.
| | - Celestine P T Chee
- Department of Materials Science and Engineering, National University of Singapore, 117575, Singapore
| | - Kou Yang
- Institute for Functional Intelligent Materials, National University of Singapore, 117544, Singapore.
| | - Siyu Chen
- Institute for Functional Intelligent Materials, National University of Singapore, 117544, Singapore.
- Department of Materials Science and Engineering, National University of Singapore, 117575, Singapore
| | - Denis Baranov
- Institute for Functional Intelligent Materials, National University of Singapore, 117544, Singapore.
| | - Colin R Woods
- Institute for Functional Intelligent Materials, National University of Singapore, 117544, Singapore.
- Department of Materials Science and Engineering, National University of Singapore, 117575, Singapore
| | - Daria V Andreeva
- Institute for Functional Intelligent Materials, National University of Singapore, 117544, Singapore.
- Department of Materials Science and Engineering, National University of Singapore, 117575, Singapore
| | - Kostya S Novoselov
- Institute for Functional Intelligent Materials, National University of Singapore, 117544, Singapore.
- Department of Materials Science and Engineering, National University of Singapore, 117575, Singapore
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2
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Meyer N, Torrent J, Balme S. Characterizing Prion-Like Protein Aggregation: Emerging Nanopore-Based Approaches. SMALL METHODS 2024:e2400058. [PMID: 38644684 DOI: 10.1002/smtd.202400058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 03/10/2024] [Indexed: 04/23/2024]
Abstract
Prion-like protein aggregation is characteristic of numerous neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases. This process involves the formation of aggregates ranging from small and potentially neurotoxic oligomers to highly structured self-propagating amyloid fibrils. Various approaches are used to study protein aggregation, but they do not always provide continuous information on the polymorphic, transient, and heterogeneous species formed. This review provides an updated state-of-the-art approach to the detection and characterization of a wide range of protein aggregates using nanopore technology. For each type of nanopore, biological, solid-state polymer, and nanopipette, discuss the main achievements for the detection of protein aggregates as well as the significant contributions to the understanding of protein aggregation and diagnostics.
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Affiliation(s)
- Nathan Meyer
- Institut Européen des Membranes, UMR5635 University of Montpellier ENCSM CNRS, Place Eugène Bataillon, Cedex 5, Montpellier, 34095, France
- INM, University of Montpellier, INSERM, Montpellier, 34095, France
| | - Joan Torrent
- INM, University of Montpellier, INSERM, Montpellier, 34095, France
| | - Sébastien Balme
- Institut Européen des Membranes, UMR5635 University of Montpellier ENCSM CNRS, Place Eugène Bataillon, Cedex 5, Montpellier, 34095, France
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3
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Ma L, Liu Z, Man J, Li J, Siwy ZS, Qiu Y. Modulation mechanism of ionic transport through short nanopores by charged exterior surfaces. NANOSCALE 2023; 15:18696-18706. [PMID: 37947348 DOI: 10.1039/d3nr04467j] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Short nanopores have various applications in biosensing, desalination, and energy conversion. Here, the modulation of ionic transport by charged exterior surfaces is investigated through simulations with sub-200 nm long nanopores under applied voltages. Detailed analysis of the ionic current, electric field strength, and fluid flow inside and outside nanopores reveals that charged exterior surfaces can increase ionic conductance by increasing both the concentration and migration speed of charge carriers. The electric double layers near charged exterior surfaces provide an ion pool and an additional passageway for counterions, which lead to enhanced exterior surface conductance and ionic concentrations at pore entrances and inside the nanopores. We also report that charges on the membrane surfaces increase the electric field strength inside nanopores. The effective width of a ring with surface charges placed at pore entrances (Lcs) is considered as well by studying the dependence of the current on Lcs. We find a linear relationship between the effective Lcs and the surface charge density and voltage, and an inverse relationship between the geometrical pore length and salt concentration. Our results elucidate the modulation mechanism of ionic transport through short nanopores by charged exterior surfaces, which is important for the design and fabrication of porous membranes.
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Affiliation(s)
- Long Ma
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education, National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan, 250061, China.
- Shenzhen Research Institute of Shandong University, Shenzhen, 518000, China
| | - Zhe Liu
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education, National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan, 250061, China.
| | - Jia Man
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education, National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan, 250061, China.
| | - Jianyong Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education, National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan, 250061, China.
| | - Zuzanna S Siwy
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | - Yinghua Qiu
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education, National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan, 250061, China.
- Shenzhen Research Institute of Shandong University, Shenzhen, 518000, China
- Suzhou Research Institute of Shandong University, Suzhou, 215123, China
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4
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Marcuccio F, Soulias D, Chau CCC, Radford SE, Hewitt E, Actis P, Edwards MA. Mechanistic Study of the Conductance and Enhanced Single-Molecule Detection in a Polymer-Electrolyte Nanopore. ACS NANOSCIENCE AU 2023; 3:172-181. [PMID: 37096230 PMCID: PMC10119975 DOI: 10.1021/acsnanoscienceau.2c00050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 12/13/2022] [Accepted: 12/14/2022] [Indexed: 04/26/2023]
Abstract
Solid-state nanopores have been widely employed in the detection of biomolecules, but low signal-to-noise ratios still represent a major obstacle in the discrimination of nucleic acid and protein sequences substantially smaller than the nanopore diameter. The addition of 50% poly(ethylene) glycol (PEG) to the external solution is a simple way to enhance the detection of such biomolecules. Here, we demonstrate with finite-element modeling and experiments that the addition of PEG to the external solution introduces a strong imbalance in the transport properties of cations and anions, drastically affecting the current response of the nanopore. We further show that the strong asymmetric current response is due to a polarity-dependent ion distribution and transport at the nanopipette tip region, leading to either ion depletion or enrichment for few tens of nanometers across its aperture. We provide evidence that a combination of the decreased/increased diffusion coefficients of cations/anions in the bath outside the nanopore and the interaction between a translocating molecule and the nanopore-bath interface is responsible for the increase in the translocation signals. We expect this new mechanism to contribute to further developments in nanopore sensing by suggesting that tuning the diffusion coefficients of ions could enhance the sensitivity of the system.
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Affiliation(s)
- Fabio Marcuccio
- School
of Electronic and Electrical Engineering, University of Leeds, LeedsLS2 9JT, U.K.
- Bragg
Centre for Materials Research, University
of Leeds, LeedsLS2 9JT, U.K.
| | - Dimitrios Soulias
- School
of Electronic and Electrical Engineering, University of Leeds, LeedsLS2 9JT, U.K.
- Bragg
Centre for Materials Research, University
of Leeds, LeedsLS2 9JT, U.K.
| | - Chalmers C. C. Chau
- School
of Electronic and Electrical Engineering, University of Leeds, LeedsLS2 9JT, U.K.
- Bragg
Centre for Materials Research, University
of Leeds, LeedsLS2 9JT, U.K.
- School
of Molecular and Cellular Biology and Astbury Centre for Structural
Molecular Biology, University of Leeds, LeedsLS2 9JT, U.K.
| | - Sheena E. Radford
- School
of Molecular and Cellular Biology and Astbury Centre for Structural
Molecular Biology, University of Leeds, LeedsLS2 9JT, U.K.
| | - Eric Hewitt
- School
of Molecular and Cellular Biology and Astbury Centre for Structural
Molecular Biology, University of Leeds, LeedsLS2 9JT, U.K.
| | - Paolo Actis
- School
of Electronic and Electrical Engineering, University of Leeds, LeedsLS2 9JT, U.K.
- Bragg
Centre for Materials Research, University
of Leeds, LeedsLS2 9JT, U.K.
| | - Martin Andrew Edwards
- Department
of Chemistry and Biochemistry, University
of Arkansas, Fayetteville, Arkansas72701, United States
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5
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Lastra LS, Bandara YMNDY, Sharma V, Freedman KJ. Protein and DNA Yield Current Enhancements, Slow Translocations, and an Enhanced Signal-to-Noise Ratio under a Salt Imbalance. ACS Sens 2022; 7:1883-1893. [PMID: 35707962 DOI: 10.1021/acssensors.2c00479] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nanopores are a promising single-molecule sensing device class that captures molecular-level information through resistive or conductive pulse sensing (RPS and CPS). The latter has not been routinely utilized in the nanopore field despite the benefits it could provide, specifically in detecting subpopulations of a molecule. A systematic study was conducted here to study the CPS-based molecular discrimination and its voltage-dependent characteristics. CPS was observed when the cation movement along both electrical and chemical gradients was favored, which led to an ∼3× improvement in SNR (i.e., signal-to-noise ratio) and an ∼8× increase in translocation time. Interestingly, a reversal of the salt gradient reinstates the more conventional resistive pulses and may help elucidate RPS-CPS transitions. The asymmetric salt conditions greatly enhanced the discrimination of DNA configurations including linear, partially folded, and completely folded DNA states, which could help detect subpopulations in other molecular systems. These findings were then utilized for the detection of a Cas9 mutant, Cas9d10a─a protein with broad utilities in genetic engineering and immunology─bound to DNA target strands and the unbound Cas9d10a + sgRNA complexes, also showing significantly longer event durations (>1 ms) than typically observed for proteins.
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Affiliation(s)
- Lauren S Lastra
- Department of Bioengineering, University of California, Riverside, 900 University Ave., Riverside, California 92521, United States
| | - Y M Nuwan D Y Bandara
- Department of Bioengineering, University of California, Riverside, 900 University Ave., Riverside, California 92521, United States
| | - Vinay Sharma
- Department of Bioengineering, University of California, Riverside, 900 University Ave., Riverside, California 92521, United States.,Department of Biosciences and Bioengineering, Indian Institute of Technology Jammu, NH-44, Jagti, Jammu and Kashmir, 181221 India
| | - Kevin J Freedman
- Department of Bioengineering, University of California, Riverside, 900 University Ave., Riverside, California 92521, United States
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6
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Lastra LS, Bandara YMNDY, Nguyen M, Farajpour N, Freedman KJ. On the origins of conductive pulse sensing inside a nanopore. Nat Commun 2022; 13:2186. [PMID: 35562332 PMCID: PMC9106702 DOI: 10.1038/s41467-022-29758-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 03/15/2022] [Indexed: 11/17/2022] Open
Abstract
Nanopore sensing is nearly synonymous with resistive pulse sensing due to the characteristic occlusion of ions during pore occupancy, particularly at high salt concentrations. Contrarily, conductive pulses are observed under low salt conditions wherein electroosmotic flow is significant. Most literature reports counterions as the dominant mechanism of conductive events (a molecule-centric theory). However, the counterion theory does not fit well with conductive events occurring via net neutral-charged protein translocation, prompting further investigation into translocation mechanics. Herein, we demonstrate theory and experiments underpinning the translocation mechanism (i.e., electroosmosis or electrophoresis), pulse direction (i.e., conductive or resistive) and shape (e.g., monophasic or biphasic) through fine control of chemical, physical, and electronic parameters. Results from these studies predict strong electroosmosis plays a role in driving DNA events and generating conductive events due to polarization effects (i.e., a pore-centric theory). Conductive events during nanopore sensing, are seen typically under low salt conditions and widely thought to arise from counterions brought into the pore via analyte. Here, authors show that an imbalance of ionic fluxes lead to conductive events.
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Affiliation(s)
- Lauren S Lastra
- Department of Bioengineering, University of California, Riverside, 900 University Avenue, Riverside, CA, 92521, USA
| | - Y M Nuwan D Y Bandara
- Department of Bioengineering, University of California, Riverside, 900 University Avenue, Riverside, CA, 92521, USA
| | - Michelle Nguyen
- Department of Biology, University of California, Riverside, 900 University Avenue, Riverside, CA, 92521, USA
| | - Nasim Farajpour
- Department of Bioengineering, University of California, Riverside, 900 University Avenue, Riverside, CA, 92521, USA
| | - Kevin J Freedman
- Department of Bioengineering, University of California, Riverside, 900 University Avenue, Riverside, CA, 92521, USA.
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7
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Zhao Y, Iarossi M, De Fazio AF, Huang JA, De Angelis F. Label-Free Optical Analysis of Biomolecules in Solid-State Nanopores: Toward Single-Molecule Protein Sequencing. ACS PHOTONICS 2022; 9:730-742. [PMID: 35308409 PMCID: PMC8931763 DOI: 10.1021/acsphotonics.1c01825] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 02/16/2022] [Accepted: 02/17/2022] [Indexed: 06/14/2023]
Abstract
Sequence identification of peptides and proteins is central to proteomics. Protein sequencing is mainly conducted by insensitive mass spectroscopy because proteins cannot be amplified, which hampers applications such as single-cell proteomics and precision medicine. The commercial success of portable nanopore sequencers for single DNA molecules has inspired extensive research and development of single-molecule techniques for protein sequencing. Among them, three challenges remain: (1) discrimination of the 20 amino acids as building blocks of proteins; (2) unfolding proteins; and (3) controlling the motion of proteins with nonuniformly charged sequences. In this context, the emergence of label-free optical analysis techniques for single amino acids and peptides by solid-state nanopores shows promise for addressing the first challenge. In this Perspective, we first discuss the current challenges of single-molecule fluorescence detection and nanopore resistive pulse sensing in a protein sequencing. Then, label-free optical methods are described to show how they address the single-amino-acid identification within single peptides. They include localized surface plasmon resonance detection and surface-enhanced Raman spectroscopy on plasmonic nanopores. Notably, we report new data to show the ability of plasmon-enhanced Raman scattering to record and discriminate the 20 amino acids at a single-molecule level. In addition, we discuss briefly the manipulation of molecule translocation and liquid flow in plasmonic nanopores for controlling molecule movement to allow high-resolution reading of protein sequences. We envision that a combination of Raman spectroscopy with plasmonic nanopores can succeed in single-molecule protein sequencing in a label-free way.
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Affiliation(s)
- Yingqi Zhao
- Istituto
Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Marzia Iarossi
- Istituto
Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | | | - Jian-An Huang
- Faculty
of Medicine, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Aapistie 5 A, 90220 Oulu, Finland
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8
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Bandara YMNDY, Farajpour N, Freedman KJ. Nanopore Current Enhancements Lack Protein Charge Dependence and Elucidate Maximum Unfolding at Protein's Isoelectric Point. J Am Chem Soc 2022; 144:3063-3073. [PMID: 35143193 DOI: 10.1021/jacs.1c11540] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Protein sequencing, as well as protein fingerprinting, has gained tremendous attention in the electrical sensing realm of solid-state nanopores and is challenging due to fast translocations and the use of high molar electrolytes. Despite providing an appreciable signal-to-noise ratio, high electrolyte concentrations can have adverse effects on the native protein structure. Herein, we present a thorough investigation of low electrolyte sensing conditions across a broad pH and voltage range generating conductive pulses (CPs) irrespective of protein net charge. We used Cas9 as the model protein and demonstrated that unfolding is noncooperative, represented by the gradual elongation or stretching of the protein, and sensitive to both the applied voltage and pH (i.e., charge state). The magnitude of unfolding and the isoelectric point (pI) of Cas9 was found to be correlated and a critical factor in our experiments. Electroosmotic flow (EOF) was always aligned with the transit direction, whereas electrophoretic force (EPF) was either reinforcing (pH < pI) or opposing (pH > pI) the protein's movement, which led to slower translocations at higher pH values. Further exploration of higher pH values led to slowing down of protein with > 30% of the population being slower than 0.5 ms. Our results would be critical for protein sensing at very low electrolytes and to retard their translocation speed without resorting to high-bandwidth equipment.
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Affiliation(s)
- Y M Nuwan D Y Bandara
- Department of Bioengineering, University of California, Riverside, 900 University Ave., Riverside, California 92521, United States
| | - Nasim Farajpour
- Department of Bioengineering, University of California, Riverside, 900 University Ave., Riverside, California 92521, United States
| | - Kevin J Freedman
- Department of Bioengineering, University of California, Riverside, 900 University Ave., Riverside, California 92521, United States
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9
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Leong IW, Tsutsui M, Yokota K, Taniguchi M. Salt Gradient Control of Translocation Dynamics in a Solid-State Nanopore. Anal Chem 2021; 93:16700-16708. [PMID: 34860500 DOI: 10.1021/acs.analchem.1c04342] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tuning capture rates and translocation time of analytes in solid-state nanopores are one of the major challenges for their use in detecting and analyzing individual nanoscale objects via ionic current measurements. Here, we report on the use of salt gradient for the fine control of capture-to-translocation dynamics in 300 nm sized SiNx nanopores. We demonstrated a decrease up to a factor of 3 in the electrophoretic speed of nanoparticles at the pore exit along with an over 3-fold increase in particle detection efficiency by subjecting a 5-fold ion concentration difference across the dielectric membrane. The improvement in the sensor performance was elucidated to be a result of the salt-gradient-mediated electric field and electroosmotic flow asymmetry at nanochannel orifices. The present findings can be used to enhance nanopore sensing capability for detecting biomolecules such as amyloids and proteins.
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Affiliation(s)
- Iat Wai Leong
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - Makusu Tsutsui
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - Kazumichi Yokota
- National Institute of Advanced Industrial Science and Technology, Takamatsu, Kagawa 761-0395, Japan
| | - Masateru Taniguchi
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
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10
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Sharma V, Freedman KJ. Pressure-Biased Nanopores for Excluded Volume Metrology, Lipid Biomechanics, and Cell-Adhesion Rupturing. ACS NANO 2021; 15:17947-17958. [PMID: 34739757 DOI: 10.1021/acsnano.1c06393] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Nanopore sensing has been widely used in applications ranging from DNA sequencing to disease diagnosis. To improve these capabilities, pressure-biased nanopores have been explored in the past to-primarily-increase the residence time of the analyte inside the pore. Here, we studied the effect of pressure on the ability to accurately quantify the excluded volume which depends on the current drop magnitude produced by a single entity. Using the calibration standard, the inverse current drop (1/ΔI) decreases linearly with increasing pressure, while the dwell drop reduces exponentially. We therefore had to derive a pressure-corrected excluded volume equation to accurately assess the volume of translocating species under applied pressure. Moreover, a method to probe deformation in nanoliposomes and a single cell is developed as a result. We show that the soft nanoliposomes and even cells deform significantly under applied pressure which can be probed in terms of the shape factor which was introduced in the excluded volume equation. The proposed work has practical applications in mechanobiology, namely, assessing the stiffness and mechanical rigidity of liposomal drug carriers. Pressure-biased pores also enabled multiple observations of cell-cell aggregates as well as their subsequent rupture, potentially allowing for the study of microbial symbioses or pathogen recognition by the human immune system.
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Affiliation(s)
- Vinay Sharma
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, California 92521, United States
- Department of Materials Engineering, Indian Institute of Technology Jammu, Jammu 181221, Jammu and Kashmir, India
| | - Kevin J Freedman
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, California 92521, United States
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11
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Wei X, Zhang Z, Wang X, Lenhart B, Gambarini R, Gray J, Liu C. Insight into the effects of electrochemical factors on host-guest interaction induced signature events in a biological nanopore. NANOTECHNOLOGY AND PRECISION ENGINEERING 2021; 3:2-8. [PMID: 33786424 PMCID: PMC8006565 DOI: 10.1016/j.npe.2019.12.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The signature events caused by host-guest interactions in the nanopore system can be used as a novel and characteristic signal in quantitative detection and analysis of various molecules. However, the effect of several electrochemical factors on the host-guest interactions in nanopore still remains unknown. Here, we systematically studied host-guest interactions, especially oscillation of DNA-azide adamantane@cucurbit[6] in α-Hemolysin nanopore under varying pH, concentration of electrolytes and counterions (Li+, Na+, K+). Our results indicate correlations between the change of pH and the duration of the oscillation signal. In addition, the asymmetric electrolyte concentration and the charge of the counterions affects the frequency of signature events in oscillation signals, and even the integrity of the protein nanopore. This study provides insight into the design of a future biosensing platform based on signature oscillation signals of the host-guest interaction within a nanopore.
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Affiliation(s)
- Xiaojun Wei
- Biomedical Engineering Program, University of South Carolina, Columbia, SC 29208, USA.,Department of Chemical Engineering, University of South Carolina, Columbia, SC 29208, USA
| | - Zehui Zhang
- Biomedical Engineering Program, University of South Carolina, Columbia, SC 29208, USA
| | - Xiaoqin Wang
- Department of Chemical Engineering, University of South Carolina, Columbia, SC 29208, USA
| | - Brian Lenhart
- Department of Chemical Engineering, University of South Carolina, Columbia, SC 29208, USA
| | - Roberto Gambarini
- Biomedical Engineering Program, University of South Carolina, Columbia, SC 29208, USA
| | - Jonathan Gray
- Biomedical Engineering Program, University of South Carolina, Columbia, SC 29208, USA
| | - Chang Liu
- Biomedical Engineering Program, University of South Carolina, Columbia, SC 29208, USA.,Department of Chemical Engineering, University of South Carolina, Columbia, SC 29208, USA
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12
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Zhou T, Ge J, Shi L, Liu Z, Deng Y, Peng Y, He X, Tang R, Wen L. Electrokinetic Translocation of a Deformable Nanoparticle through a Nanopore. ACS APPLIED BIO MATERIALS 2020; 3:5160-5168. [PMID: 35021692 DOI: 10.1021/acsabm.0c00606] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The nanopore-based biosensing technology is built up on the fluctuation of the ionic current induced by the electrokinetic translation of a particle penetrating the nanopore. It is expected that the current change of a deformable bioparticle is dissimilar from that of a rigid one. This study theoretically investigated the transient translocation process of a deformable particle through a nanopore for the first time. The mathematical model considers the Poisson equation for the electric potential, the Nernst-Planck equations for the ionic transport, the Navier-Stokes equations for the flow field, and the stress-strain equation for the dynamics of the deformable bioparticle. The arbitrary Lagrangian-Eulerian method is used for the fully coupled particle-fluid dynamic interaction. Results show that the deformation degree of the particle, the velocity deviation, and the current is different from the rigid particle. The deformation degree of the particle will reach the maximum when the particle passes a nanopore. Because of the deformation of particles, the total force applied on deformable particles is larger than that of rigid particles, resulting in larger velocity deviation and current deviation. The influences of the ratio of the nanoparticle radius to the Debye length and surface charge density of the nanopore are also studied. The research results illustrate the translocation mechanism of a deformable nanoparticle in the nanopore, which can provide theoretical guidance for the biosensing technology based on the nanopore.
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Affiliation(s)
- Teng Zhou
- Mechanical and Electrical Engineering College, Hainan University, Haikou 570228, Hainan, China
| | - Jian Ge
- Mechanical and Electrical Engineering College, Hainan University, Haikou 570228, Hainan, China
| | - Liuyong Shi
- Mechanical and Electrical Engineering College, Hainan University, Haikou 570228, Hainan, China
| | - Zhenyu Liu
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Sciences, Changchun 130033, China
| | - Yongbo Deng
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Sciences, Changchun 130033, China
| | - Yinyin Peng
- Mechanical and Electrical Engineering College, Hainan University, Haikou 570228, Hainan, China
| | - Xiaohan He
- Mechanical and Electrical Engineering College, Hainan University, Haikou 570228, Hainan, China
| | - Rongnian Tang
- Mechanical and Electrical Engineering College, Hainan University, Haikou 570228, Hainan, China
| | - Liping Wen
- CAS Key Laboratory of Bio-inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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13
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Zhang Y, Zhao J, Kan Y, Ji R, Pan J, Huang W, Xu Z, Si W, Sha J. Concentration effects on capture rate and translocation configuration of nanopore-based DNA detection. Electrophoresis 2020; 41:1523-1528. [PMID: 32529653 DOI: 10.1002/elps.202000016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 01/21/2023]
Abstract
Nanopore is a kind of powerful tool to detect single molecules and investigate fundamental biological processes. In biological cells or real detection systems, concentration of DNA molecules is various. Here, we report an experimental study of the effects of DNA concentration on capture rate and translocation configuration with different sized nanopores and applied voltages. Three classes of DNA translocation configurations have been observed including linear translocation, folded translocation, and cotranslocation. In the case of relatively large sized nanopore or high applied voltage, considerable cotranslocation events have been detected. The percentage of cotranslocation events also increases with DNA concentration, which leads to the relationship between capture rate and DNA concentration deviates from linearity. Therefore, in order to reflect the number of translocation molecules accurately, the capture rate should be corrected by double-counting cotranslocation events. These results will provide a valuable reference for the design of nanopore sensors.
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Affiliation(s)
- Yin Zhang
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, P. R. China
| | - Jiabin Zhao
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, P. R. China
| | - Yajing Kan
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, P. R. China
| | - Rui Ji
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, P. R. China
| | - Jianqiang Pan
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, P. R. China
| | - Weichi Huang
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, P. R. China
| | - Zheng Xu
- Key Laboratory for Micro/Nano Technology and System of Liaoning Province, Dalian University of Technology, Dalian, P. R. China
| | - Wei Si
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, P. R. China
| | - Jingjie Sha
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, P. R. China
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14
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Zeng S, Wen C, Li S, Chen X, Chen S, Zhang SL, Zhang Z. Controlled size reduction and its underlying mechanism to form solid-state nanopores via electron beam induced carbon deposition. NANOTECHNOLOGY 2019; 30:455303. [PMID: 31394513 DOI: 10.1088/1361-6528/ab39a2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Solid-state nanopores have drawn considerable attention for their potential applications in DNA sequencing and nanoparticle analysis. However, fabrication of nanopores, especially those of diameter below 30 nm, requires sophisticated techniques. Here, a versatile method to controllably reduce the diameter of prefabricated large-size pores down to sub-30 nm without greatly increasing the effective pore depth from the original membrane thickness is shown. This method exploits carbon deposition achieved via hydrocarbon evaporation, induced by an incident beam of electrons, and subsequent dissociation of hydrocarbon to solid carbon deposits. The carbon deposition employs a conventional scanning electron microscope equipped with direct visual feedback, along with a stable hydrocarbon source nearby the sample. This work systematically studies how electron beam accelerating voltage, imaging magnification, initial pore size and membrane composition affect the process of pore size reduction. Secondary electrons generated in the membrane material are confirmed to be the main cause of the dissociation of hydrocarbon. Thicker carbon deposited on one side than on the other of the membrane results in an asymmetric nanopore shape and a rectifying ionic transport. A physico-phenomenological model combined with Monte Carlo simulations is proposed to account for the observed carbon deposition behaviors.
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Affiliation(s)
- Shuangshuang Zeng
- Division of Solid-State Electronics, Department of Engineering Sciences, Uppsala University, SE-751 21 Uppsala, Sweden
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15
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Mo J, Sha J, Li D, Li Z, Chen Y. Fluid release pressure for nanochannels: the Young-Laplace equation using the effective contact angle. NANOSCALE 2019; 11:8408-8415. [PMID: 30985837 DOI: 10.1039/c8nr08987f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Releasing fluids from nanochannels is quite challenging, yet crucial for the application of nanofluidic systems, e.g. drug delivery and nanoprinting. Previous work suggests that the pressure required to activate the releasing is enormously high (50 to above 300 MPa), while its underlying mechanism still remains unclear. In this work, through molecular dynamics simulations, we have identified a critical tilt angle of the hydrophilic nanochannel, below which spontaneous release of water is achieved. A significant increase in the contact angle is observed during the fluid releasing process due to the transition from the solid fluid contact to the fluid vapor contact. Such transition in nanoscale channels can significantly raise the release pressure by at most ∼30 MPa depending on the channel height and surface property, which makes the classical Young-Laplace equation underestimate the release pressure. By incorporating the derived formula for the largest effective contact angle, a modified Young-Laplace equation is developed, which predicts the release pressure well for both hydrophobic and hydrophilic channels down to the nanoscale. Furthermore, it is discovered that for nanoscale channels, the decreased rate of the normalized release pressure as a function of the contact angle becomes fast when the surface energy of the channel grows strong. The fast decreased rate is mainly caused by the adsorption of water molecules at the exit when the surface becomes highly hydrophilic.
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Affiliation(s)
- Jingwen Mo
- Jiangsu Key Laboratory for Design & Manufacture of Micro/Nano Biomedical Instruments and School of Mechanical Engineering, Southeast University, Nanjing 210096, P.R. China.
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16
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Sui XJ, Li MY, Ying YL, Yan BY, Wang HF, Zhou JL, Gu Z, Long YT. Aerolysin Nanopore Identification of Single Nucleotides Using the AdaBoost Model. JOURNAL OF ANALYSIS AND TESTING 2019. [DOI: 10.1007/s41664-019-00088-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Roshan KA, Tang Z, Guan W. High fidelity moving Z-score based controlled breakdown fabrication of solid-state nanopore. NANOTECHNOLOGY 2019; 30:095502. [PMID: 30523901 DOI: 10.1088/1361-6528/aaf48e] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We investigate the current transport characteristics in the electrolyte-dielectric-electrolyte structure commonly used in the in situ controlled breakdown (CBD) fabrication of solid-state nanopores. It is found that the stochastic breakdown process could lead to fidelity issues of false positives (an incorrect indication of a true nanopore formation) and false negatives (inability to detect initial nanopore formation). Robust and deterministic detection of initial physical breakdown to alleviate false positives and false negatives is critical for precise nanopore size control. To this end, we report a high fidelity moving Z-score method based CBD fabrication of solid-state nanopore. We demonstrate 100% success rate of realizing the initial nanopore conductance of 3 ± 1 nS (corresponds to size of 1.7 ± 0.6 nm) regardless of the dielectric membrane characteristics. Our study also elucidates the Joule heating is the dominant mechanism for electric field-based nanopore enlargement. Single DNA molecule sensing using nanopores fabricated by this method was successfully demonstrated. We anticipate the moving Z-score based CBD method could enable broader access to the solid state nanopore-based single molecule analysis.
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Affiliation(s)
- Kamyar Akbari Roshan
- Department of Electrical Engineering, Pennsylvania State University, University Park 16802, United States of America
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18
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Hu ZL, Li MY, Liu SC, Ying YL, Long YT. A lithium-ion-active aerolysin nanopore for effectively trapping long single-stranded DNA. Chem Sci 2019; 10:354-358. [PMID: 30746084 PMCID: PMC6334748 DOI: 10.1039/c8sc03927e] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 11/12/2018] [Indexed: 12/15/2022] Open
Abstract
Wild-type aerolysin (AeL) nanopores allow direct single nucleotide discrimination of very short oligonucleotides (≤10 nt) without labelling, which shows great potential for DNA sensing. To achieve real applications, one major obstacle of AeL is its poor capture ability of long single-stranded DNA (ssDNA, >10 nt). Here, we have proposed a novel and robust strategy for the electrostatic focusing of long ssDNA into a lithium-chloride (LiCl)-active AeL. By using this method, for the first time we have demonstrated AeL detection of ssDNA longer than 100 nt. Due to screening more negative charges, LiCl improves AeL capture ability of long ssDNA (i.e. 60 nt) by 2.63- to 10.23-fold compared to KCl. Further calculations and molecular dynamics simulations revealed that strong binding between Li+ and the negatively charged residue neutralized the AeL, leading to a reduction in the energy barrier for ssDNA capture. These findings facilitate the future high-throughput applications of AeL in genetic and epigenetic diagnostics.
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Affiliation(s)
- Zheng-Li Hu
- Key Laboratory for Advanced Materials , School of Chemistry and Molecular Engineering , East China University of Science and Technology , Shanghai , 200237 , P. R. China . ; Tel: +86-21-64252339
| | - Meng-Yin Li
- Key Laboratory for Advanced Materials , School of Chemistry and Molecular Engineering , East China University of Science and Technology , Shanghai , 200237 , P. R. China . ; Tel: +86-21-64252339
| | - Shao-Chuang Liu
- Key Laboratory for Advanced Materials , School of Chemistry and Molecular Engineering , East China University of Science and Technology , Shanghai , 200237 , P. R. China . ; Tel: +86-21-64252339
| | - Yi-Lun Ying
- Key Laboratory for Advanced Materials , School of Chemistry and Molecular Engineering , East China University of Science and Technology , Shanghai , 200237 , P. R. China . ; Tel: +86-21-64252339
| | - Yi-Tao Long
- Key Laboratory for Advanced Materials , School of Chemistry and Molecular Engineering , East China University of Science and Technology , Shanghai , 200237 , P. R. China . ; Tel: +86-21-64252339
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19
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Sha J, Si W, Xu B, Zhang S, Li K, Lin K, Shi H, Chen Y. Identification of Spherical and Nonspherical Proteins by a Solid-State Nanopore. Anal Chem 2018; 90:13826-13831. [DOI: 10.1021/acs.analchem.8b04136] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Jingjie Sha
- School of Mechanical Engineering, Southeast University, Nanjing 211189, China
- Jiangsu Key Laboratory for Design and Manufacture of Micro-nano Biomedical Instruments, Southeast University, Nanjing 211189, China
| | - Wei Si
- School of Mechanical Engineering, Southeast University, Nanjing 211189, China
- Jiangsu Key Laboratory for Design and Manufacture of Micro-nano Biomedical Instruments, Southeast University, Nanjing 211189, China
| | - Bing Xu
- School of Mechanical Engineering, Southeast University, Nanjing 211189, China
- Jiangsu Key Laboratory for Design and Manufacture of Micro-nano Biomedical Instruments, Southeast University, Nanjing 211189, China
| | - Shuai Zhang
- School of Mechanical Engineering, Southeast University, Nanjing 211189, China
- Jiangsu Key Laboratory for Design and Manufacture of Micro-nano Biomedical Instruments, Southeast University, Nanjing 211189, China
| | - Kun Li
- School of Mechanical Engineering, Southeast University, Nanjing 211189, China
- Jiangsu Key Laboratory for Design and Manufacture of Micro-nano Biomedical Instruments, Southeast University, Nanjing 211189, China
| | - Kabin Lin
- School of Mechanical Engineering, Southeast University, Nanjing 211189, China
- Jiangsu Key Laboratory for Design and Manufacture of Micro-nano Biomedical Instruments, Southeast University, Nanjing 211189, China
| | - Hongjiao Shi
- School of Mechanical Engineering, Southeast University, Nanjing 211189, China
- Jiangsu Key Laboratory for Design and Manufacture of Micro-nano Biomedical Instruments, Southeast University, Nanjing 211189, China
| | - Yunfei Chen
- School of Mechanical Engineering, Southeast University, Nanjing 211189, China
- Jiangsu Key Laboratory for Design and Manufacture of Micro-nano Biomedical Instruments, Southeast University, Nanjing 211189, China
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20
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Wang Y, Yan S, Zhang P, Zeng Z, Zhao D, Wang J, Chen H, Huang S. Osmosis-Driven Motion-Type Modulation of Biological Nanopores for Parallel Optical Nucleic Acid Sensing. ACS APPLIED MATERIALS & INTERFACES 2018; 10:7788-7797. [PMID: 29431423 DOI: 10.1021/acsami.7b18347] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Recent developments in nanopore sequencing have inspired new concepts in precision medicine but limited in throughput. By optically encoding calcium flux from an array of nanopores, parallel measurements from hundreds of nanopores were reported, while lateral drifts of biological nanopores set obstacles for signal processing. In this paper, optical single-channel recording (oSCR) serves to track nanopores with high precision and a general principle of nanopore motion kinetics is quantitatively investigated. By finely adjusting the osmosis-oriented interactions between the lipid/substrate interfaces, motions of nanopores could be controllably restricted. Improved signal-to-noise ratio is observed from motion-restricted nanopores, which is experimentally demonstrated. To systematically evaluate oSCR with asymmetric salt concentrations, a finite element method simulation is established. oSCR with an array of immobilized nanopores suggests new strategies for sequencing DNA by microscopic imaging in high throughput and is widely applicable to the investigation of other transmembrane proteins.
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Affiliation(s)
| | | | | | - Zidao Zeng
- Department of Chemistry , University of Pittsburgh , 219 Parkman Avenue , Pittsburgh , Pennsylvania 15260 , United States
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21
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Lam J, Lutsko JF. Solute particle near a nanopore: influence of size and surface properties on the solvent-mediated forces. NANOSCALE 2017; 9:17099-17108. [PMID: 29087410 DOI: 10.1039/c7nr07218j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Nanoscopic pores are used in various systems to attract nanoparticles. In general the behaviour is a result of two types of interactions: the material specific affinity and the solvent-mediated influence also called the depletion force. The latter is more universal but also much more complex to understand since it requires modeling both the nanoparticle and the solvent. Here, we employed classical density functional theory to determine the forces acting on a nanoparticle near a nanoscopic pore as a function of its hydrophobicity and its size. A simple capillary model is constructed to predict those depletion forces for various surface properties. For a nanoscopic pore, complexity arises from both the specific geometry and the fact that hydrophobic pores are not necessarily filled with liquid. Taking all of these effects into account and including electrostatic effects, we establish a phase diagram describing the entrance and the rejection of the nanoparticle from the pore.
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Affiliation(s)
- Julien Lam
- Center for Nonlinear Phenomena and Complex Systems, Code Postal 231, Université Libre de Bruxelles, Boulevard du Triomphe, 1050 Brussels, Belgium.
| | - James F Lutsko
- Center for Nonlinear Phenomena and Complex Systems, Code Postal 231, Université Libre de Bruxelles, Boulevard du Triomphe, 1050 Brussels, Belgium.
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22
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Qiu Y, Siwy Z. Probing charges on solid-liquid interfaces with the resistive-pulse technique. NANOSCALE 2017; 9:13527-13537. [PMID: 28871289 DOI: 10.1039/c7nr03998k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Our manuscript addresses the issue of probing an effective surface charge that any surface can acquire at the solid/liquid interface. Even if a particle is predicted to be neutral based on its chemical structure, the particle can carry finite surface charges when placed in a solution. We present tools to probe the presence of surface charge densities of meso-particles, characterized with zeta potentials below 10 mV. The tools are based on the resistive-pulse technique, which uses single pores to probe properties of individual objects including molecules, particles, and cells. The presented experiments were performed with particles 280 and 400 nm in diameter and single pores with opening diameter tuned between ∼ 200 nm and one micron. Surface charge properties were probed in two modes: (i) the passage of the particles through pores of diameters larger than the particles, as well as (ii) an approach curve of a particle to a pore that is smaller than the particle diameter. The curve in the latter mode has a biphasic character starting with a low-amplitude current decrease, followed by a current enhancement reaching an amplitude of ∼10% of the baseline current. The current increase was long-lasting and stable, and shown to strongly depend on the particle surface charge density. The results are explained via voltage-modulation of ionic concentrations in the pore.
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Affiliation(s)
- Yinghua Qiu
- Department of Physics and Astronomy, University of California, Irvine, CA 92697, USA.
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23
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Ivica J, Williamson PTF, de Planque MRR. Salt Gradient Modulation of MicroRNA Translocation through a Biological Nanopore. Anal Chem 2017; 89:8822-8829. [DOI: 10.1021/acs.analchem.7b01246] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Josip Ivica
- Electronics
and Computer Science, ‡Centre for Biological Sciences, and §Institute for
Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Philip T. F. Williamson
- Electronics
and Computer Science, ‡Centre for Biological Sciences, and §Institute for
Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Maurits R. R. de Planque
- Electronics
and Computer Science, ‡Centre for Biological Sciences, and §Institute for
Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
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24
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Aaronson BDB, Wigmore D, Johns MA, Scott JL, Polikarpov I, Marken F. Cellulose ionics: switching ionic diode responses by surface charge in reconstituted cellulose films. Analyst 2017; 142:3707-3714. [DOI: 10.1039/c7an00918f] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cellulose films as well as chitosan-modified cellulose films of approximately 5 μm thickness, reconstituted from ionic liquid media onto a poly(ethylene-terephthalate) (PET, 6 μm thickness) film with a 5, 10, 20, or 40 μm diameter laser-drilled microhole, show significant current rectification in aqueous NaCl.
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Affiliation(s)
| | - David Wigmore
- Department of Chemistry
- University of Bath
- Bath BA2 7AY
- UK
| | - Marcus A. Johns
- Department of Chemistry
- University of Bath
- Bath BA2 7AY
- UK
- Centre for Sustainable Chemical Technologies
| | | | - Igor Polikarpov
- São Carlos Institute of Physics-IFSC
- University of São Paulo- USP
- 13566-590 São Carlos
- Brazil
| | - Frank Marken
- Department of Chemistry
- University of Bath
- Bath BA2 7AY
- UK
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