101
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Lomas JS. Self- and hetero-association of sterically hindered tertiary alcohols. J PHYS ORG CHEM 2005. [DOI: 10.1002/poc.950] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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102
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Self-assembly of a new series of quadruply hydrogen bonded heterotrimers driven by the donor–acceptor interaction. Tetrahedron 2005. [DOI: 10.1016/j.tet.2005.07.075] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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103
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Frankamp BL, Boal AK, Tuominen MT, Rotello VM. Direct Control of the Magnetic Interaction between Iron Oxide Nanoparticles through Dendrimer-Mediated Self-Assembly. J Am Chem Soc 2005; 127:9731-5. [PMID: 15998077 DOI: 10.1021/ja051351m] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cationic superparamagnetic iron oxide nanoparticles were assembled using a series of anionic polyamidoamine dendrimers. The resulting assemblies featured systematically increasing average interparticle spacing over a 2.4 nm range with increasing dendrimer generation. This increase in spacing modulated the collective magnetic behavior by effective lowering of the dipolar coupling between particles. The results obtained in these studies deviate from the predicted dependence of collective behavior on interparticle spacing, suggesting that a dense assembly of magnetically "free" particles can exist with a surprisingly small space between particles.
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Affiliation(s)
- Benjamin L Frankamp
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, USA
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104
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Johnson JM, Tang J, Nyame Y, Willits D, Young MJ, Zlotnick A. Regulating self-assembly of spherical oligomers. NANO LETTERS 2005; 5:765-770. [PMID: 15826125 DOI: 10.1021/nl050274q] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In multistep reactions, stability of intermediates is critical to the rate of product formation and a significant factor in generating kinetic traps. The capsid protein of cowpea chlorotic mottle virus (CCMV) can be induced to assemble into spherical particles of 30, 60, and 90 dimers. Based on examining assembly kinetics and reaction end points, we find that formation of uniform, ordered structures is not always a result of reactions that reach equilibrium. Equilibration or, alternatively, kinetic trapping can be identified by a straightforward analysis. Altering the assembly path of "spherical" particles is a means of controlling the distribution of products, which has broad applicability to self-assembly reactions.
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Affiliation(s)
- Jennifer M Johnson
- Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73190, USA
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105
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Schalley CA. Elements for the construction of molecular devices: template effects and self‐assembly. J PHYS ORG CHEM 2004. [DOI: 10.1002/poc.826] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Christoph A. Schalley
- Kekulé‐Institut für Organische Chemie und Biochemie der Universität, Gerhard‐Domagk‐Strasse 1, D‐53121 Bonn, Germany
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106
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Li XQ, Feng DJ, Jiang XK, Li ZT. Donor–acceptor interaction-mediated arrangement of hydrogen bonded dimers. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.06.104] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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107
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Abstract
Molecular simulations are performed to study the self-assembly of particles with discrete, attractive interaction sites - "patches" - at prescribed locations on the particle surface. Chains, sheets, rings, icosahedra, square pyramids, tetrahedra, and twisted and staircase structures are obtained through suitable design of the surface pattern of patches. Our simulations predict that the spontaneous formation of two-dimensional sheets and icosahedra occurs via a first-order transition while the formation of chains occurs via a continuous disorder-to-order transition as in equilibrium polymerization. Our results show how precise arrangements of patches combined with patch "recognition" or selectivity may be used to control the relative position of particles and the overall structure of particle assemblies. In this context, patchy particles represent a new class of building block for the fabrication of precise structures.
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Affiliation(s)
- Zhenli Zhang
- Departments of Chemical Engineering and Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136
| | - Sharon C Glotzer
- Departments of Chemical Engineering and Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136
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108
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Clark J, Singer EM, Korns DR, Smith SS. Design and analysis of nanoscale bioassemblies. Biotechniques 2004; 36:992-6, 998-1001. [PMID: 15211750 DOI: 10.2144/04366rv01] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Bionanotechnology is an emerging field in nanotechnology. In general, it uses concepts from chemistry, biochemistry, and molecular biology to identify components and processes for the construction of self-assembling materials and devices. Distant goals of the science of bionanotechnology range from developing programmable nanoscale devices that can sample or alter their environments to developing assemblies capable of Darwinian evolution. At the heart of these approaches is the concept of the production of supramolecular assemblies (SMAs; also known as supramolecular aggregates) by programmed self-assembly in an aqueous medium. Ordered arrays, planar and closed-shell tilings, dynamic machines, and switches have been designed and constructed by using DNA-DNA, protein-protein, and protein-nucleic acid biospecificities. We review the designs and the analytical techniques that have been employed in the production of SMAs that do not occur in nature.
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Affiliation(s)
- Jarrod Clark
- Kaplan Clinical Research Laboratory, City of Hope National Medical Center, 1500 E. Duarte Road, Duarte, CA, USA.
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109
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110
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Nowicki W, Nowicka G. The interfacial energy of two-dimensional bidisperse cellular fluids. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2004; 13:409-415. [PMID: 15170540 DOI: 10.1140/epje/i2003-10086-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Abstract. The mixing energy of two biphasic fluid systems (dispersions of two liquids or a liquid and a gas, A and B in a liquid C), confined between two parallel plates, is calculated. Our attention is limited to concentrated and monodisperse systems, i.e. emulsions and foam/emulsions consisting of equal-size (if of the same composition) cells separated by a thin liquid film. It is demonstrated that the multiphase mixtures ordered into regular patterns can be stable in a wide range of interfacial tensions acting along A-C and B-C interfaces and also in a wide range of volume fractions of fluid A. Anisotropic properties of such well-ordered structures are also demonstrated.
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Affiliation(s)
- W Nowicki
- Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780, Poznan, Poland.
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111
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112
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113
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Pan Z, Zhu H, Zhang Z, Im HJ, Dai S, Beach DB, Lowndes DH. Patterned Growth of Vertically Aligned Carbon Nanotubes on Pre-patterned Iron/Silica Substrates Prepared by Sol−Gel and Shadow Masking. J Phys Chem B 2003. [DOI: 10.1021/jp026850d] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zhengwei Pan
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6201, and Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056
| | - Haoguo Zhu
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6201, and Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056
| | - Zongtao Zhang
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6201, and Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056
| | - Hee-jung Im
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6201, and Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056
| | - Sheng Dai
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6201, and Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056
| | - David B. Beach
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6201, and Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056
| | - Douglas H. Lowndes
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6201, and Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056
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114
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Schmuck C, Wienand W. Highly stable self-assembly in water: ion pair driven dimerization of a guanidiniocarbonyl pyrrole carboxylate zwitterion. J Am Chem Soc 2003; 125:452-9. [PMID: 12517158 DOI: 10.1021/ja028485+] [Citation(s) in RCA: 164] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of a novel water-soluble guanidiniocarbonyl pyrrole carboxylate zwitterion 2 is described, and its self-association in aqueous solutions is studied. Zwitterion 2 forms extremely stable 1:1 dimers which are held together by an extensive hydrogen bonding network in combination with two mutual interacting ion pairs as could be shown by ESI MS and X-ray structure determination. NMR dilution studies in different highly polar solvents showed that dimerization is fast on the NMR time scale with association constants ranging from an estimated 10(10) M(-1) in DMSO to a surprisingly high 170 M(-1) in water. Hence, zwitterion 2 belongs to the most efficient self-assembling systems solely on the basis of electrostatic interactions reported so far. Furthermore, an amidopyridine pyrrole carboxylic acid 10 was developed as a neutral analogue of zwitterion 2, which also dimerizes with an essentially identical hydrogen bonding pattern (according to ESI MS and X-ray structure determination) but lacking the ionic interactions. NMR binding studies demonstrated that the solely hydrogen-bonded neutral dimer of 10 is stable only in organic solvents of low polarity (K > 10(4) M(-1) in CDCl3 but <10 M(-1) in 5% DMSO in CDCl3). The comparison of both systems impressively underlines the importance of ion pair interactions for stable self-association of such H-bonded binding motifs in water.
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Affiliation(s)
- Carsten Schmuck
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, Germany
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115
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Affiliation(s)
- Tianwei Lin
- Department of Molecular Biology, Center for Integrative Molecular Biosciences, Scripps Research Institute, La Jolla, California 92037, USA
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116
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Field-configured self-assembly: manufacturing at the mesoscale. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2003. [DOI: 10.1016/s0928-4931(02)00226-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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117
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Mao C, Thalladi VR, Wolfe DB, Whitesides S, Whitesides GM. Dissections: self-assembled aggregates that spontaneously reconfigure their structures when their environment changes. J Am Chem Soc 2002; 124:14508-9. [PMID: 12465940 DOI: 10.1021/ja021043d] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This Communication describes a new strategy for the design of adaptive structures based on reconfigurable mesoscale self-assembly. Several sets of millimeter-scale objects have been designed that can self-assemble into two different, regular aggregates at the interface between an aqueous solution and perfluorodecalin; the choice between the two aggregates is determined by the density of the aqueous phase.
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Affiliation(s)
- Chengde Mao
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA
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118
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Park JS, Lee GS, Lee YJ, Park YS, Yoon KB. Organization of microcrystals on glass by adenine-thymine hydrogen bonding. J Am Chem Soc 2002; 124:13366-7. [PMID: 12418872 DOI: 10.1021/ja0270569] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Shaking of adenine-tethering glass plates in an aqueous suspension of micrometer-sized, thymine-tethering zeolite crystals such as ZSM-5 (0.6 mum x 1.7 mum x 2.5 mum) or zeolite-A (1.7 mum x 1.7 mum x 1.7 mum) for 3 h at room temperature leads to facile assembly of monolayers of the zeolite microcrystals on the glass plates through the hydrogen-bonding interaction between the tethered adenine and thymine. Control experiments show that the presence of adenine and thymine on the respective solid surface is essential for the monolayer assembly. This establishes that even the micrometer-sized building blocks can be organized by a large number of well-defined weak hydrogen bonding. Increase in the assembly temperature to annealing temperatures leads to a marked increase in the rate of monolayer assembly and in the size of the domain in which zeolite crystals are closely packed in the same three-dimensional orientation.
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Affiliation(s)
- Jin Seon Park
- Center for Microcrystal Assembly, Department of Chemistry, Sogang University, Seoul 121-742, Korea
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119
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Thalladi VR, Schwartz A, Phend JN, Hutchinson JW, Whitesides GM. Simulation of indentation fracture in crystalline materials using mesoscale self-assembly. J Am Chem Soc 2002; 124:9912-7. [PMID: 12175253 DOI: 10.1021/ja020577b] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new physical model based on mesoscale self-assembly is developed to simulate indentation fracture in crystalline materials. Millimeter-scale hexagonal objects exhibiting atom-like potential functions were designed and allowed to self-assemble into two-dimensional (2D) aggregates at the interface between water and perfluorodecalin. Indentation experiments were performed on these aggregates, and the stresses and strains involved in these processes were evaluated. The stress field in the aggregates was analyzed theoretically using the 2D elastic Hertz solution. Comparison of the experimental results with theoretical analysis revealed that fracture develops in regions subjected to high shear stress and some, albeit low, tensile stress. The potential for the broader application of the model is illustrated using indentation of assemblies with point defects and adatoms introduced at predetermined locations, and using a two-phase aggregate simulating a compliant film on a stiff substrate.
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Affiliation(s)
- Venkat R Thalladi
- Department of Chemistry and Chemical Biology, and Division of Engineering and Applied Sciences, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA
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120
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Clark TD, Ferrigno R, Tien J, Paul KE, Whitesides GM. Template-directed self-assembly of 10-microm-sized hexagonal plates. J Am Chem Soc 2002; 124:5419-26. [PMID: 11996582 DOI: 10.1021/ja020056o] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This article presents a strategy for the fabrication of ordered microstructures using concepts of design inspired by molecular self-assembly and template-directed synthesis. The self-assembling components are 4-microm-thick hexagonal metal plates having sides 10 microm in length ("hexagons"), and each template consists of a 4-microm-thick circular metal plate surrounding a central cavity, the perimeter of which is complementary in shape to the external edges of a two-dimensional, close-packed array of hexagons. The hexagons and templates (collectively, "pieces") were fabricated via standard procedures and patterned into hydrophobic and hydrophilic regions using self-assembled monolayers (SAMs). Templated self-assembly occurs in water through capillary interactions between thin films of a nonpolar liquid adhesive coating the hydrophobic faces of the pieces. The hexagons tile the cavities enclosed by the templates, and the boundaries of the cavities determine the sizes and shapes of the assemblies. Curing the adhesive with ultraviolet light furnishes mechanically stable arrays having well-defined morphologies. By allowing control over the structures of the resulting aggregates, this work represents a step toward the development of practical methods for microfabrication based on self-assembly.
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Affiliation(s)
- Thomas D Clark
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA
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121
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Whitesides GM, Boncheva M. Beyond molecules: self-assembly of mesoscopic and macroscopic components. Proc Natl Acad Sci U S A 2002; 99:4769-74. [PMID: 11959929 PMCID: PMC122665 DOI: 10.1073/pnas.082065899] [Citation(s) in RCA: 911] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Self-assembly is a process in which components, either separate or linked, spontaneously form ordered aggregates. Self-assembly can occur with components having sizes from the molecular to the macroscopic, provided that appropriate conditions are met. Although much of the work in self-assembly has focused on molecular components, many of the most interesting applications of self-assembling processes can be found at larger sizes (nanometers to micrometers). These larger systems also offer a level of control over the characteristics of the components and over the interactions among them that makes fundamental investigations especially tractable.
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Affiliation(s)
- George M Whitesides
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
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122
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Boncheva M, Gracias DH, Jacobs HO, Whitesides GM. Biomimetic self-assembly of a functional asymmetrical electronic device. Proc Natl Acad Sci U S A 2002; 99:4937-40. [PMID: 11959945 PMCID: PMC122698 DOI: 10.1073/pnas.032667599] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
This paper introduces a biomimetic strategy for the fabrication of asymmetrical, three-dimensional electronic devices modeled on the folding of a chain of polypeptide structural motifs into a globular protein. Millimeter-size polyhedra-patterned with logic devices, wires, and solder dots-were connected in a linear string by using flexible wire. On self-assembly, the string folded spontaneously into two domains: one functioned as a ring oscillator, and the other one as a shift register. This example demonstrates that biomimetic principles of design and self-organization can be applied to generate multifunctional electronic systems of complex, three-dimensional architecture.
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Affiliation(s)
- Mila Boncheva
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
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123
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Lehn JM. Toward complex matter: supramolecular chemistry and self-organization. Proc Natl Acad Sci U S A 2002; 99:4763-8. [PMID: 11929970 PMCID: PMC122664 DOI: 10.1073/pnas.072065599] [Citation(s) in RCA: 926] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Jean-Marie Lehn
- Institut de Science et d'Ingénierie Supramoléculaires, Université Louis Pasteur, 67000 Strasbourg, France.
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124
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Jacobs HO, Tao AR, Schwartz A, Gracias DH, Whitesides GM. Fabrication of a cylindrical display by patterned assembly. Science 2002; 296:323-5. [PMID: 11951039 DOI: 10.1126/science.1069153] [Citation(s) in RCA: 318] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We demonstrate the patterned assembly of integrated semiconductor devices onto planar, flexible, and curved substrates on the basis of capillary interactions involving liquid solder. The substrates presented patterned, solder-coated areas that acted both as receptors for the components of the device during its assembly and as electrical connections during its operation. The components were suspended in water and agitated gently. Minimization of the free energy of the solder-water interface provided the driving force for the assembly. One hundred and thirteen GaAlAs light-emitting diodes with a chip size of 280 micrometers were fabricated into a prototype cylindrical display. It was also possible to assemble 1500 silicon cubes, on an area of 5 square centimeters, in less than 3 minutes, with a defect rate of approximately 2%.
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Affiliation(s)
- Heiko O Jacobs
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA.
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125
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126
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127
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128
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129
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Affiliation(s)
- Qian Wang
- Department of Chemistry, The Scripps Research Institute, 10550 N. Torrey Pines Rd., La Jolla, CA 92037, USA
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130
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131
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Clark TD, Boncheva M, German JM, Weck M, Whitesides GM. Design of three-dimensional, millimeter-scale models for molecular folding. J Am Chem Soc 2002; 124:18-9. [PMID: 11772052 DOI: 10.1021/ja0120633] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This communication describes the fabrication of three-dimensional structures of organic polymers using principles of design inspired by protein folding. The structures consist of rigid polyhedral components with dimensions of a few millimeters ("microdomains"), representing alpha-helical and beta-sheet secondary structures, connected with flexible linkers representing loops or turns. These structures were fabricated from polyurethane using photolithographic and soft lithographic techniques. The surfaces of the microdomains were patterned into hydrophobic and hydrophilic regions, and a hydrophobic photocurable liquid (serving both as lubricant and adhesive) was selectively precipitated onto the hydrophobic areas. The unfolded structures were suspended in water and agitated by tumbling. Self-assembly occurred through coalescence of the thin films of hydrophobic liquid, and was caused by minimization of the free energy of the interface between the liquid adhesive and the water. The self-assembled structures were locked in place by curing the adhesive with UV light. These results demonstrate the use of concepts abstracted from the study of proteins-including attractive hydrophobic interactions, shape complementarity, and conformational constraint-in the self-assembly of complex, three-dimensional structures on the millimeter scale.
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Affiliation(s)
- Thomas D Clark
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA
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132
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Selbstkomplementäre Vier-Wasserstoffbrücken-Bindungsmotive als funktionales Prinzip: von dimeren Übermolekülen zu supramolekularen Polymeren. Angew Chem Int Ed Engl 2001. [DOI: 10.1002/1521-3757(20011203)113:23<4493::aid-ange4493>3.0.co;2-e] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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133
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Smith DP, Radford SE. Role of the single disulphide bond of beta(2)-microglobulin in amyloidosis in vitro. Protein Sci 2001; 10:1775-84. [PMID: 11514668 PMCID: PMC2253195 DOI: 10.1110/ps.4901] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2001] [Revised: 05/17/2001] [Accepted: 05/29/2001] [Indexed: 10/16/2022]
Abstract
The aggregation of beta(2)-microglobulin (beta(2)m) into amyloid fibrils occurs in the condition known as dialysis-related amyloidosis (DRA). The protein has a beta-sandwich fold typical of the immunoglobulin family, which is stabilized by a highly conserved disulphide bond linking Cys25 and Cys80. Oxidized beta(2)m forms amyloid fibrils rapidly in vitro at acidic pH and high ionic strength. Here we investigate the role of the single disulphide bond of beta(2)m in amyloidosis in vitro. We show that reduction of the disulphide bond destabilizes the native protein such that non-native molecules are populated at neutral pH. These species are prone to oligomerization but do not form amyloid fibrils when incubated for up to 8 mo at pH 7.0 in 0.4 M NaCl. Over the pH range 4.0-1.5 in the presence of 0.4 M NaCl, however, amyloid fibrils of reduced beta(2)m are formed. These fibrils are approximately 10 nm wide, but are shorter and assemble more rapidly than those produced from the oxidized protein. These data show that population of non-native conformers of beta(2)m at neutral pH by reduction of its single disulphide bond is not sufficient for amyloid formation. Instead, association of one or more specific partially unfolded molecules formed at acid pH are necessary for the formation of beta(2)m amyloid in vitro. Further experiments will now be needed to determine the role of different oligomeric species of beta(2)m in the toxicity of the protein in vivo.
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Affiliation(s)
- D P Smith
- School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT UK
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134
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Oliver SR, Clark TD, Bowden N, Whitesides GM. Three-dimensional self-assembly of complex, millimeter-scale structures through capillary bonding. J Am Chem Soc 2001; 123:8119-20. [PMID: 11506570 DOI: 10.1021/ja010845q] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- S R Oliver
- Department of Chemistry and Chemical Biology Harvard University, 12 Oxford Street Cambridge, Massachusetts 02138, USA
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135
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Clark TD, Tien J, Duffy DC, Paul KE, Whitesides GM. Self-assembly of 10-microm-sized objects into ordered three-dimensional arrays. J Am Chem Soc 2001; 123:7677-82. [PMID: 11480990 DOI: 10.1021/ja010634l] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This paper describes the self-assembly of small objects--polyhedral metal plates with largest dimensions of 10 to 30 microm--into highly ordered, three-dimensional arrays. The plates were fabricated using photolithography and electrodeposition techniques, and the faces of the plates were functionalized to be hydrophobic or hydrophilic using self-assembled monolayers (SAMs). Self-assembly occurs in water through capillary interactions between thin films of a hydrophobic liquid (a liquid prepolymer adhesive) coated onto the hydrophobic faces of the plates; coalescence of the adhesive films reduces the interfacial free energy of the system and drives self-assembly. By altering the size and surface-patterning of the plates, the external morphologies of the aggregates were varied. Curing the adhesive furnished mechanically stable aggregates that were characterized by scanning electron microscopy (SEM). For assemblies formed by plates partially composed of a sacrificial material, a subsequent etching step furnished fully open, three-dimensional microstructures. This work validates the use of capillary interactions for three-dimensional mesoscale self-assembly in the 10-microm-size regime and opens new avenues for the fabrication of complex, three-dimensional microscructures.
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Affiliation(s)
- T D Clark
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA
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