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Zhang LL, Zhong CB, Huang TJ, Zhang LM, Yan F, Ying YL. High-throughput single biomarker identification using droplet nanopore. Chem Sci 2024; 15:8355-8362. [PMID: 38846401 PMCID: PMC11151865 DOI: 10.1039/d3sc06795e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 03/28/2024] [Indexed: 06/09/2024] Open
Abstract
Biomarkers are present in various metabolism processes, demanding precise and meticulous analysis at the single-molecule level for accurate clinical diagnosis. Given the need for high sensitivity, biological nanopore have been applied for single biomarker sensing. However, the detection of low-volume biomarkers poses challenges due to their low concentrations in dilute buffer solutions, as well as difficulty in parallel detection. Here, a droplet nanopore technique is developed for low-volume and high-throughput single biomarker detection at the sub-microliter scale, which shows a 2000-fold volume reduction compared to conventional setups. To prove the concept, this nanopore sensing platform not only enables multichannel recording but also significantly lowers the detection limit for various types of biomarkers such as angiotensin II, to 42 pg. This advancement enables direct biomarker detection at the picogram level. Such a leap forward in detection capability positions this nanopore sensing platform as a promising candidate for point-of-care testing of biomarker at single-molecule level, while substantially minimizing the need for sample dilution.
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Affiliation(s)
- Lin-Lin Zhang
- Molecular Sensing and Imaging Center, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 P. R. China
| | - Cheng-Bing Zhong
- Molecular Sensing and Imaging Center, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 P. R. China
| | - Ting-Jing Huang
- Molecular Sensing and Imaging Center, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 P. R. China
| | - Li-Min Zhang
- School of Electronic Science and Engineering, Nanjing University Nanjing 210023 P. R. China
| | - Feng Yan
- School of Electronic Science and Engineering, Nanjing University Nanjing 210023 P. R. China
| | - Yi-Lun Ying
- Molecular Sensing and Imaging Center, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 P. R. China
- State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University Nanjing 210023 P. R. China
- Chemistry and Biomedicine Innovation Center, Nanjing University Nanjing 210023 P. R. China
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2
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Ngassam VN, Su WC, Gettel DL, Deng Y, Yang Z, Wang-Tomic N, Sharma VP, Purushothaman S, Parikh AN. Recurrent dynamics of rupture transitions of giant lipid vesicles at solid surfaces. Biophys J 2021; 120:586-597. [PMID: 33460597 DOI: 10.1016/j.bpj.2021.01.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 11/20/2020] [Accepted: 01/07/2021] [Indexed: 10/22/2022] Open
Abstract
Single giant unilamellar vesicles (GUVs) rupture spontaneously from their salt-laden suspension onto solid surfaces. At hydrophobic surfaces, the GUVs rupture via a recurrent, bouncing ball rhythm. During each contact, the GUVs, rendered tense by the substrate interactions, porate, and spread a molecularly transformed motif of a monomolecular layer on the hydrophobic surface from the point of contact in a symmetric manner. The competition from pore closure, however, limits the spreading and produces a daughter vesicle, which re-engages with the substrate. At solid hydrophilic surfaces, by contrast, GUVs rupture via a distinctly different recurrent burst-heal dynamics; during burst, single pores nucleate at the contact boundary of the adhering vesicles, facilitating asymmetric spreading and producing a "heart"-shaped membrane patch. During the healing phase, the competing pore closure produces a daughter vesicle. In both cases, the pattern of burst-reseal events repeats multiple times, splashing and spreading the vesicular fragments as bilayer patches at the solid surface in a pulsatory manner. These remarkable recurrent dynamics arise, not because of the elastic properties of the solid surface, but because the competition between membrane spreading and pore healing, prompted by the surface-energy-dependent adhesion, determine the course of the topological transition.
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Affiliation(s)
- Viviane N Ngassam
- Department of Biomedical Engineering, University of California, Davis, California
| | - Wan-Chih Su
- Department of Chemistry, University of California, Davis, California
| | - Douglas L Gettel
- Department of Chemical Engineering, University of California, Davis, California
| | - Yawen Deng
- Department of Biomedical Engineering, University of California, Davis, California
| | - Zexu Yang
- Department of Biomedical Engineering, University of California, Davis, California
| | - Neven Wang-Tomic
- Department of Biomedical Engineering, University of California, Davis, California
| | - Varun P Sharma
- Department of Biomedical Engineering, University of California, Davis, California
| | - Sowmya Purushothaman
- Department of Biomedical Engineering, University of California, Davis, California
| | - Atul N Parikh
- Department of Biomedical Engineering, University of California, Davis, California; Department of Chemistry, University of California, Davis, California; Department of Chemical Engineering, University of California, Davis, California; Department of Materials Science and Engineering, University of California, Davis, California.
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3
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Jõemetsa S, Spustova K, Kustanovich K, Ainla A, Schindler S, Eigler S, Lobovkina T, Lara-Avila S, Jesorka A, Gözen I. Molecular Lipid Films on Microengineering Materials. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:10286-10298. [PMID: 31369272 DOI: 10.1021/acs.langmuir.9b01120] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In this study, we have systematically investigated the formation of molecular phospholipid films on a variety of solid substrates fabricated from typical surface engineering materials and the fluidic properties of the lipid membranes formed on these substrates. The surface materials comprise of borosilicate glass, mica, SiO2, Al (native oxide), Al2O3, TiO2, ITO, SiC, Au, Teflon AF, SU-8, and graphene. We deposited the lipid films from small unilamellar vesicles (SUVs) by means of an open-space microfluidic device, observed the formation and development of the films by laser scanning confocal microscopy, and evaluated the mode and degree of coverage, fluidity, and integrity. In addition to previously established mechanisms of lipid membrane-surface interaction upon bulk addition of SUVs on solid supports, we observed nontrivial lipid adhesion phenomena, including reverse rolling of spreading bilayers, spontaneous nucleation and growth of multilamellar vesicles, and the formation of intact circular patches of double lipid bilayer membranes. Our findings allow for accurate prediction of membrane-surface interactions in microfabricated devices and experimental environments where model membranes are used as functional biomimetic coatings.
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Affiliation(s)
- Silver Jõemetsa
- Department of Physics , Chalmers University of Technology , Fysikgränd 3 , 412 96 Gothenburg , Sweden
| | - Karolina Spustova
- Centre for Molecular Medicine Norway, Faculty of Medicine , University of Oslo , Gaustadalléen 21 , 0349 Oslo , Norway
| | - Kiryl Kustanovich
- Department of Chemistry and Chemical Engineering , Chalmers University of Technology , Kemigården 4 , 412 96 Gothenburg , Sweden
| | - Alar Ainla
- International Iberian Nanotechnology Laboratory , Av. Mestre José Veiga , 4715-330 Braga , Portugal
| | - Severin Schindler
- Department of Chemistry and Chemical Engineering , Chalmers University of Technology , Kemigården 4 , 412 96 Gothenburg , Sweden
| | - Siegfried Eigler
- Institut für Chemie und Biochemie , Freie Universität Berlin , Takustraße 3 , 14195 Berlin , Germany
| | - Tatsiana Lobovkina
- Department of Chemistry and Chemical Engineering , Chalmers University of Technology , Kemigården 4 , 412 96 Gothenburg , Sweden
| | - Samuel Lara-Avila
- Department of Microtechnology and Nanoscience , Chalmers University of Technology , Kemivägen 9 , 412 96 , Gothenburg , Sweden
- National Physical Laboratory , Hampton Road , TW11 0LW Teddington , U.K
| | - Aldo Jesorka
- Department of Chemistry and Chemical Engineering , Chalmers University of Technology , Kemigården 4 , 412 96 Gothenburg , Sweden
| | - Irep Gözen
- Centre for Molecular Medicine Norway, Faculty of Medicine , University of Oslo , Gaustadalléen 21 , 0349 Oslo , Norway
- Department of Chemistry and Chemical Engineering , Chalmers University of Technology , Kemigården 4 , 412 96 Gothenburg , Sweden
- Department of Chemistry, Faculty of Mathematics and Natural Sciences , University of Oslo , Sem Sælands vei 26 , 0371 Oslo , Norway
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4
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Bilayer membrane interactions with nanofabricated scaffolds. Chem Phys Lipids 2015; 192:75-86. [DOI: 10.1016/j.chemphyslip.2015.07.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 07/16/2015] [Accepted: 07/25/2015] [Indexed: 01/17/2023]
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5
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Shaali M, Lara-Avila S, Dommersnes P, Ainla A, Kubatkin S, Jesorka A. Nanopatterning of mobile lipid monolayers on electron-beam-sculpted Teflon AF surfaces. ACS NANO 2015; 9:1271-1279. [PMID: 25541906 DOI: 10.1021/nn5050867] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Direct electron-beam lithography is used to fabricate nanostructured Teflon AF surfaces, which are utilized to pattern surface-supported monolayer phospholipid films with 50 nm lateral feature size. In comparison with unexposed Teflon AF coatings, e-beam-irradiated areas show reduced surface tension and surface potential. For phospholipid monolayer spreading experiments, these areas can be designed to function as barriers that enclose unexposed areas of nanometer dimensions and confine the lipid film within. We show that the effectiveness of the barrier is defined by pattern geometry and radiation dose. This surface preparation technique represents an efficient, yet simple, nanopatterning strategy supporting studies of lipid monolayer behavior in ultraconfined spaces. The generated structures are useful for imaging studies of biomimetic membranes and other specialized surface applications requiring spatially controlled formation of self-assembled, molecularly thin films on optically transparent patterned polymer surfaces with very low autofluorescence.
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Affiliation(s)
- Mehrnaz Shaali
- Department of Chemical and Biological Engineering and ‡Quantum Device Physics Laboratory, Chalmers University of Technology , 41296 Gothenburg, Sweden
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6
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Hannestad JK, Brune R, Czolkos I, Jesorka A, El-Sagheer AH, Brown T, Albinsson B, Orwar O. Kinetics of diffusion-mediated DNA hybridization in lipid monolayer films determined by single-molecule fluorescence spectroscopy. ACS NANO 2013; 7:308-315. [PMID: 23215045 DOI: 10.1021/nn304010p] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We use single-molecule fluorescence microscopy to monitor individual hybridization reactions between membrane-anchored DNA strands, occurring in nanofluidic lipid monolayer films deposited on Teflon AF substrates. The DNA molecules are labeled with different fluorescent dyes, which make it possible to simultaneously monitor the movements of two different molecular species, thus enabling tracking of both reactants and products. We employ lattice diffusion simulations to determine reaction probabilities upon interaction. The observed hybridization rate of the 40-mer DNA was more than 2-fold higher than that of the 20-mer DNA. Since the lateral diffusion coefficient of the two different constructs is nearly identical, the effective molecule radius determines the overall kinetics. This implies that when two DNA molecules approach each other, hydrogen bonding takes place distal from the place where the DNA is anchored to the surface. Strand closure then propagates bidirectionally through a zipper-like mechanism, eventually bringing the lipid anchors together. Comparison with hybridization rates for corresponding DNA sequences in solution reveals that hybridization rates are lower for the lipid-anchored strands and that the dependence on strand length is stronger.
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Affiliation(s)
- Jonas K Hannestad
- Department of Chemical and Biological Engineering, Chalmers University of Technology, 412 96, Göteborg, Sweden
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7
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Czolkos I, Hakonen B, Orwar O, Jesorka A. High-resolution micropatterned Teflon AF substrates for biocompatible nanofluidic devices. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:3200-3205. [PMID: 22204476 DOI: 10.1021/la2044784] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We describe a general photolithography-based process for the microfabrication of surface-supported Teflon AF structures. Teflon AF patterns primarily benefit from superior optical properties such as very low autofluorescence and a low refractive index. The process ensures that the Teflon AF patterns remain strongly hydrophobic in order to allow rapid lipid monolayer spreading and generates a characteristic edge morphology which assists directed cell growth along the structured surfaces. We provide application examples, demonstrating the well-controlled mixing of lipid films on Teflon AF structures and showing how the patterned surfaces can be used as biocompatible growth-directing substrates for cell culture. Chinese hamster ovary (CHO) cells develop in a guided fashion along the sides of the microstructures, selectively avoiding to grow over the patterned areas.
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Affiliation(s)
- Ilja Czolkos
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 412 96 Göteborg, Sweden
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8
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Kleinert J, Kim S, Velev OD. Electric-field-controlled flow in nanoscale-thin wetting films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:3037-3044. [PMID: 22195978 DOI: 10.1021/la204774s] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A novel nanofluidic system based on electroosmotic flow in nanoscale-thin aqueous wetting films is reported. The water films formed spontaneously on mica substrates in a saturation humidity environment. The film thickness was determined to be a few tens of nanometers by optical interference and fluorescence intensity measurements and was consistent with a theoretical evaluation of the thickness of a film based on the competing forces of electrostatic repulsion and capillary pressure. Lateral flow was induced by applying a dc electric field tangential to the film and characterized by tracking the position of a fluorescent probe. The mobilities of the thin fluid layer and the flow marker were lower than the predictions of the electrokinetic theory, which may be a result of adsorption of the fluorescent molecules to the mica. Confinement of the film to two-dimensional "channels" was achieved by microcontact printing of patterned hydrophobic monolayers onto the substrate. This system has the advantage of simple and inexpensive fabrication in comparison to nanofluidic devices made by traditional lithography techniques.
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Affiliation(s)
- Jairus Kleinert
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695-7905, United States
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9
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Zan GH, Tan C, Deserno M, Lanni F, Lösche M. Hemifusion of giant unilamellar vesicles with planar hydrophobic surfaces: a fluorescence microscopy study. SOFT MATTER 2012; 8:10877-10886. [PMID: 25383087 PMCID: PMC4222682 DOI: 10.1039/c2sm25702e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Vesicle adhesion and fusion to interfaces are frequently used for the construction of biomimetic surfaces in biosensors and drug delivery. Ubiquitous in cell biology, vesicle fusion involves the transformation of two separate membranes into one contiguous lipid bilayer. In distinction, the deposition of vesicle membranes to hydrophobic surfaces requires the transformation of a lipidic bilayer into a monomolecular layer - a topologically distinct process termed hemifusion. Here, we used hydrophobically terminated self-assembled monolayers (SAMs) on solid surfaces to track the hemifusion of fluorescently labeled giant unilamellar vesicles (GUVs) at the single vesicle level with video time resolution (≈53 ms). We observed that a dilute monolayer, consisting of lipid extracted from the outer GUV leaflet, spreads outward across the hydrophobic surface from the vesicle adhesion site. Subsequently, bilayer hemifusion occurs by vesicle rupture near the hydrophobic surface, followed by spreading of lipid in a dense monolayer. GUV lipids thus transfer to the SAM surface in two concentric zones: an outer hemifusion zone comprises lipids drawn from the outer GUV leaflet and an inner hemifusion zone comprises lipids from both the inner and outer GUV leaflets and grows at a rate of ≈1000 µm2 s-1 (dA/dt = 970 ± 430 µm2 s-1 in n = 22 independent experiments). This growth rate is quantitatively consistent with the assumption that the spreading of the monolayer is entirely driven by the difference in surface energies of the hydrophobic and the lipid-covered SAM surfaces, which is dissipated by friction of the spreading monolayer on the SAM. Lipid transfer between the inner and outer GUV leaflets occurs via a hemifusion pore that forms early in the process near the membrane contact site. This pore also permits expulsion of water from the GUV interior as the vesicle contracts onto the contact site.
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Affiliation(s)
- Goh Haw Zan
- Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213-3890, USA
| | - Cheemeng Tan
- Ray and Stephanie Lane Center for Computational Biology, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213-3890, USA
| | - Markus Deserno
- Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213-3890, USA
| | - Frederick Lanni
- Department of Biological Sciences, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213-3890, USA
| | - Mathias Lösche
- Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213-3890, USA
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213-3890, USA
- National Institute of Standards and Technology, Center for Neutron Research, Gaithersburg, MD 20899-6102, USA
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10
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Wittenberg NJ, Im H, Johnson TW, Xu X, Warrington AE, Rodriguez M, Oh SH. Facile assembly of micro- and nanoarrays for sensing with natural cell membranes. ACS NANO 2011; 5:7555-64. [PMID: 21842844 PMCID: PMC3183111 DOI: 10.1021/nn202554t] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Microarray technology has facilitated many powerful high-throughput studies in the fields of genetics and proteomics, among others. However, preparation of microarrays composed of cell-derived membranes with embedded receptors has proven difficult. Here we describe a new method for forming microarrays composed of synthetic lipid vesicles and natural cell membranes. The method is based upon assembly of vesicles and natural membranes into recessed micro- and nanowells and using a polydimethylsiloxane (PDMS) block as a "squeegee." This method is used to assemble phospholipid vesicles into arrays with micrometer and nanoscale dimensions. Native myelin and neuronal lipid raft arrays are also formed in 30 min or less. We show the natural membrane arrays can be used for sensing lipid-protein interactions by detecting cholera toxin binding to ganglioside GM1 in neuronal lipid rafts. In multicomponent arrays myelin can be distinguished from neuronal rafts by antibody binding to cell-specific surface antigens. Finally, myelin arrays formed in gold nanowells are used for surface plasmon resonance sensing. This assembly approach is simple, broadly applicable, and opens up new avenues of research not easily accomplished with standard microarray technology.
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Affiliation(s)
- Nathan J. Wittenberg
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Hyungsoon Im
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Timothy W. Johnson
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Xiaohua Xu
- Departments of Neurology and Immunology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Arthur E. Warrington
- Departments of Neurology and Immunology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Moses Rodriguez
- Departments of Neurology and Immunology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Sang-Hyun Oh
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA
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11
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Börjesson K, Tumpane J, Ljungdahl T, Wilhelmsson LM, Nordén B, Brown T, Mårtensson J, Albinsson B. Membrane-anchored DNA assembly for energy and electron transfer. J Am Chem Soc 2010; 131:2831-9. [PMID: 19199439 DOI: 10.1021/ja8038294] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this work we examine the trapping and conversion of visible light energy into chemical energy using a supramolecular assembly. The assembly consists of a light-absorbing antenna and a porphyrin redox center, which are covalently attached to two complementary 14-mer DNA strands, hybridized to form a double helix and anchored to a lipid membrane. The excitation energy is finally trapped in the lipid phase of the membrane as a benzoquinone radical anion that could potentially be used in subsequent chemical reactions. In addition, in this model complex, the hydrophobic porphyrin moiety acts as an anchor into the liposome positioning the DNA construct on the lipid membrane surface. The results show the suitability of our system as a prototype for DNA-based light-harvesting devices, in which energy transfer from the aqueous phase to the interior of the lipid membrane is followed by charge separation.
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Affiliation(s)
- Karl Börjesson
- Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-41296 Gothenburg, Sweden
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12
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Controlled solvent-exchange deposition of phospholipid membranes onto solid surfaces. Biointerphases 2010; 5:1-8. [DOI: 10.1116/1.3319326] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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13
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Ainla A, Gözen I, Orwar O, Jesorka A. A microfluidic diluter based on pulse width flow modulation. Anal Chem 2009; 81:5549-56. [PMID: 19476370 DOI: 10.1021/ac9010028] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We demonstrate that pulse width flow modulation (PWFM) can be used to design fast, accurate, and precise multistage dilution modules for microfluidic devices. The PWFM stage unit presented here yields 10-fold dilution, but several PWFM stages can be connected in series to yield higher-order dilutions. We have combined two stages in a device thus capable of diluting up to 100-fold, and we have experimentally determined a set of rules that can be conveniently utilized to design multistage diluters. Microfabrication with resist-based molds yielded geometrical channel height variances of 7% (22.9(16) microm) with corresponding hydraulic resistance variances of approximately 20%. Pulsing frequencies, channel lengths, and flow pressures can be chosen within a wide range to establish the desired diluter properties. Finally, we illustrate the benefits of on-chip dilution in an example application where we investigate the effect of the Ca(2+) concentration on a phospholipid bilayer spreading from a membrane reservoir onto a SiO(2) surface. This is one of many possible applications where flexible concentration control is desirable.
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Affiliation(s)
- Alar Ainla
- Department of Chemical and Biological Engineering, and Microtechnology Centre (MC2), Chalmers University of Technology, SE-412 96, Göteborg, Sweden
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14
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Czolkos I, Hannestad JK, Jesorka A, Kumar R, Brown T, Albinsson B, Orwar O. Platform for controlled supramolecular nanoassembly. NANO LETTERS 2009; 9:2482-2486. [PMID: 19507892 DOI: 10.1021/nl901254f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We here present a two-dimensional (2D) micro/nano-fluidic technique where reactant-doped liquid-crystal films spread and mix on micro- and nanopatterned substrates. Surface-supported phospholipid monolayers are individually doped with complementary DNA molecules which hybridize when these lipid films mix. Using lipid films to convey reactants reduces the dimensionality of traditional 3D chemistry to 2D, and possibly to 1D by confining the lipid film to nanometer-sized lanes. The hybridization event was observed by FRET using single-molecule-sensitive confocal fluorescence detection. We could successfully detect hybridization in lipid streams on 250 nm wide lanes. Our results show that the number and density of reactants as well as sequence of reactant addition can be controlled within confined liquid crystal films, providing a platform for nanochemistry with potential for kinetic control.
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Affiliation(s)
- Ilja Czolkos
- Department of Chemical and Biological Engineering, Chalmers University of Technology, 412 96, Goteborg, Sweden
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15
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Tagami Y, Matsufuji T, Ikigai H, Narita T, Oishi Y. Pressure Dependence of Aggregation State of (DMPC/Cholesterol) Mixed Monolayer Based on AFM Observation. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2009. [DOI: 10.1246/bcsj.82.536] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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16
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Complex Nanotube-Liposome Networks. Methods Enzymol 2009. [DOI: 10.1016/s0076-6879(09)64015-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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17
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Xia D, Brueck SRJ. Strongly anisotropic wetting on one-dimensional nanopatterned surfaces. NANO LETTERS 2008; 8:2819-2824. [PMID: 18680349 DOI: 10.1021/nl801394w] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
This communication reports strongly anisotropic wetting behavior on one-dimensional nanopatterned surfaces. Contact angles, degree of anisotropy, and droplet distortion are measured on micro- and nanopatterned surfaces fabricated with interference lithography. Both the degree of anisotropy and the droplet distortion are extremely high as compared with previous reports because of the well-defined nanostructural morphology. The surface is manipulated to tune with the wetting from hydrophobic to hydrophilic while retaining the structural wetting anisotropy with a simple silica nanoparticle overcoat. The wetting mechanisms are discussed. Potential applications in microfluidic devices and evaporation-induced pattern formation are demonstrated.
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Affiliation(s)
- Deying Xia
- Center for High Technology Materials and Department of Electrical and Computer Engineering, University of New Mexico, 1313 Goddard, SE, Albuquerque, New Mexico 87106, USA
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18
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Erkan Y, Halma K, Czolkos I, Jesorka A, Dommersnes P, Kumar R, Brown T, Orwar O. Controlled release of chol-TEG-DNA from Nano- and micropatterned SU-8 surfaces by a spreading lipid film. NANO LETTERS 2008; 8:227-231. [PMID: 18069872 DOI: 10.1021/nl0725087] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We report the controlled release of immobilized cholesteryl-tetraethyleneglycol-DNA (chol-DNA) from micropatterned SU-8 surfaces by a spreading lipid film. The release of chol-DNA is rapid and on the order of the spreading rate of the lipid film beta = 1-3 microm2/s ( approximately 10(5) molecules of DNA per second). The lipid film serves as a poor solvent for the DNA adduct, which upon contact redistributes into the aqueous phase. Thus, the release of DNA is accompanied by a change in surface hydrophobicity. The method can be used for creating arbitrary concentration profiles of DNA in solution over time or to dynamically change surface properties on demand in, for example, micro- and nanofluidic devices. Examples of DNA release from spiral, comb, meander, and triangular as well as from nanoscale SU-8 lanes are shown.
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Affiliation(s)
- Yavuz Erkan
- Department of Chemical and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
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