MATERIALS SCIENCE: Enhanced: Self-Assembly of Unusual Nanoparticle Crystals

Science ◽  
2006 ◽  
Vol 312 (5772) ◽  
pp. 376-377 ◽  
Author(s):  
O. D. Velev
Keyword(s):  
Self Assembly ◽  
Materials Science

Investigation of Au SAMs Photoclick Derivatization by PM-IRRAS

2019 ◽  
Author(s):  
Mark Workentin ◽  
François Lagugné-Labarthet ◽  
Sidney Legge
Keyword(s):  
Cell Adhesion ◽  
Self Assembly ◽  
Materials Science ◽  
Fibroblast Cell ◽  
Fine Tuning ◽  
Chemical System ◽  
Infrared Reflection ◽  
Assembled Monolayers ◽  
One Step ◽  
High Degree

In this work we present a clean one-step process for modifying headgroups of self-assembled monolayers (SAMs) on gold using photo-enabled click chemistry. A thiolated, cyclopropenone-caged strained alkyne precursor was first functionalized onto a flat gold substrate through self-assembly. Exposure of the cyclopropenone SAM to UV-A light initiated the efficient photochemical decarbonylation of the cyclopropenone moiety, revealing the strained alkyne capable of undergoing the interfacial strain-promoted alkyne-azide cycloaddition (SPAAC). Irradiated SAMs were derivatized with a series of model azides with varied hydrophobicity to demonstrate the generality of this chemical system for the modification and fine-tuning of the surface chemistry on gold substrates. SAMs were characterized at each step with polarization-modulation infrared reflection-absorption spectroscopy (PM-IRRAS) to confirm successful functionalization and reactivity. Furthermore, to showcase the compatibility of this approach with biochemical applications, cyclopropenone SAMs were irradiated and modified with azide-bearing cell adhesion peptides to promote human fibroblast cell adhesion, then imaged by live cell fluorescence microscopy. Thus, the “photoclick” methodology reported here represents an improved, versatile, catalyst-free protocol that allows for a high degree of control over the modification of material surfaces, with applicability in materials science as well as biochemistry.<br>

DNA-based self-assembly of nanostructures

2017 ◽  
Author(s):  
Joshua D. Carter ◽  
Chenxiang Lin ◽  
Yan Liu ◽  
Hao Yan ◽  
Thomas H. LaBean
Keyword(s):  
Self Assembly ◽  
Materials Science ◽  
Directed Assembly ◽  
Building Blocks ◽  
Hierarchical Assembly ◽  
Synthetic Dna ◽  
Nanoscale Manufacturing ◽  
Covalently Linked ◽  
Design Construction ◽  
Proteins And Peptides

This article examines the DNA-based self-assembly of nanostructures. It first reviews the development of DNA self-assembly and DNA-directed assembly, focusing on the main strategies and building blocks available in the modern molecular construction toolbox, including the design, construction, and analysis of nanostructures composed entirely of synthetic DNA, as well as origami nanostructures formed from a mixture of synthetic and biological DNA. In particular, it considers the stepwise covalent synthesis of DNA nanomaterials, unmediated assembly of DNA nanomaterials, hierarchical assembly, nucleated assembly, and algorithmic assembly. It then discusses DNA-directed assembly of heteromaterials such as proteins and peptides, gold nanoparticles, and multicomponent nanostructures. It also describes the use of complementary DNA cohesion as 'smart glue' for bringing together covalently linked functional groups, biomolecules, and nanomaterials. Finally, it evaluates the potential future of DNA-based self-assembly for nanoscale manufacturing for applications in medicine, electronics, photonics, and materials science.

Zeolates: A Coordination Chemistry View of Metal-Ligand Bonding in Intrazeolite MOCVD Type Precursors and Semiconductor Nanoclusters

1992 ◽  
Vol 277 ◽  
Author(s):  
Geoffrey A. Ozin ◽  
Carol L. Bowes ◽  
Mark R. Steele
Keyword(s):  
Self Assembly ◽  
Materials Science ◽  
Zeolite Y ◽  
Chemical Vapour ◽  
Internal Surface ◽  
Building Blocks ◽  
Structural Features ◽  
Organic Chemical ◽  
Wide Range ◽  
Shape Selective

ABSTRACTVarious MOCVD (metal-organic chemical vapour deposition) type precursors and their self-assembled semiconductor nanocluster products [1] have been investigated in zeolite Y hosts. From analysis of in situ observations (FTIR, UV-vis reflectance, Mössbauer, MAS-NMR) of the reaction sequences and structural features of the precursors and products (EXAFS and Rietveld refinement of powder XRD data) the zeolite is viewed as providing a macrospheroidal, multidendate coordination environment towards encapsulated guests. By thinking about the α- and β-cages of the zeolite Y host effectively as a zeolate ligand composed of interconnected aluminosilicate “crown ether-like” building blocks, the materials chemist is able to better understand and exploit the reactivity and coordination properties of the zeolite internal surface for the anchoring and self-assembly of a wide range of encapsulated guests. This approach helps with the design of synthetic strategies for creating novel guest-host inclusion compounds having possible applications in areas of materials science such as nonlinear optics, quantum electronics, and size/shape selective catalysis.

MATERIALS SCIENCE: Directing Self-Assembly Toward Perfection

Science ◽  
2008 ◽  
Vol 321 (5891) ◽  
pp. 919-920 ◽  
Author(s):  
R. A. Segalman
Keyword(s):  
Self Assembly ◽  
Materials Science

Self Assembling Nanostructured Delivery Vehicles for Biochemically Reactive Pairs

1994 ◽  
Vol 351 ◽  
Author(s):  
Nir Kossovsky ◽  
A. Gelman ◽  
H.J. Hnatyszyn ◽  
E. Sponsler ◽  
G.-M. Chow
Keyword(s):  
Physical Properties ◽  
Self Assembly ◽  
Materials Science ◽  
Technology Development ◽  
Biological Behavior ◽  
X Ray Diffraction ◽  
Self Assembling ◽  
Transmission Electron ◽  
Carbon Ceramic

ABSTRACTIntrigued by the deceptive simplicity and beauty of macromolecular self-assembly, our laboratory began studying models of self-assembly using solids, glasses, and colloidal substrates. These studies have defined a fundamental new colloidal material for supporting members of a biochemically reactive pair.The technology, a molecular transportation assembly, is based on preformed carbon ceramic nanoparticles and self assembled calcium-phosphate dihydrate particles to which glassy carbohydrates are then applied as a nanometer thick surface coating. This carbohydrate coated core functions as a dehydroprotectant and stabilizes surface immobilized members of a biochemically reactive pair. The final product, therefore, consists of three layers. The core is comprised of the ceramic, the second layer is the dehydroprotectant carbohydrate adhesive, and the surface layer is the biochemically reactive molecule for which delivery is desired.We have characterized many of the physical properties of this system and have evaluated the utility of this delivery technology in vitro and in animal models. Physical characterization has included standard and high resolution transmission electron microscopy, electron and x-ray diffraction and ζ potential analysis. Functional assays of the ability of the system to act as a nanoscale dehydroprotecting delivery vehicle have been performed on viral antigens, hemoglobin, and insulin. By all measures at present, the favorable physical properties and biological behavior of the molecular transportation assembly point to an exciting new interdisciplinary area of technology development in materials science, chemistry and biology.

scholarly journals Living supramolecular polymerization of fluorinated cyclohexanes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Oleksandr Shyshov ◽  
Shyamkumar Vadakket Haridas ◽  
Luca Pesce ◽  
Haoyuan Qi ◽  
Andrea Gardin ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Self Assembly ◽  
Materials Science ◽  
Helical Structure ◽  
The Self ◽  
Supramolecular Polymers ◽  
Aliphatic Compound ◽  
Double Helical Structure ◽  
Key Driver ◽  
Supramolecular Polymerization

AbstractThe development of powerful methods for living covalent polymerization has been a key driver of progress in organic materials science. While there have been remarkable reports on living supramolecular polymerization recently, the scope of monomers is still narrow and a simple solution to the problem is elusive. Here we report a minimalistic molecular platform for living supramolecular polymerization that is based on the unique structure of all-cis 1,2,3,4,5,6-hexafluorocyclohexane, the most polar aliphatic compound reported to date. We use this large dipole moment (6.2 Debye) not only to thermodynamically drive the self-assembly of supramolecular polymers, but also to generate kinetically trapped monomeric states. Upon addition of well-defined seeds, we observed that the dormant monomers engage in a kinetically controlled supramolecular polymerization. The obtained nanofibers have an unusual double helical structure and their length can be controlled by the ratio between seeds and monomers. The successful preparation of supramolecular block copolymers demonstrates the versatility of the approach.

scholarly journals Design and Validation of a Frugal, Automated, Solid-Phase Peptide Synthesizer

2020 ◽  
Author(s):  
Nathaniel E. Kallmyer ◽  
Nathan E. Rider ◽  
Nigel F. Reuel
Keyword(s):  
Peptide Synthesis ◽  
Self Assembly ◽  
Synthetic Peptides ◽  
Materials Science ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Fluid Handling ◽  
Price Point ◽  
Grade Fluid ◽  
Chemistry Laboratories

AbstractSolid phase peptide synthesis (SPPS) has enabled widespread use of synthetic peptides in applications ranging from pharmaceuticals to materials science. The demand for synthetic peptides has driven recent efforts to produce automated SPPS synthesizers which utilize fluid-handling components common to chemistry laboratories to drive costs down to several thousand dollars. Herein, we describe the design and validation of a more ‘frugal’ SPPS synthesizer that uses inexpensive, consumer-grade fluid-handling components to achieve a prototype price point between US$300 and $600. We demonstrated functionality by preparing and characterizing peptides with a variety of distinct properties including binding functionality, nanoscale self-assembly, and oxidation-induced fluorescence. This system yielded micromoles of peptide at a cost of approximately $1/residue, a cost which may be further reduced by optimization and bulk purchasing.

MATERIALS SCIENCE: Template-Assisted Self-Assembly

Science ◽  
2001 ◽  
Vol 293 (5535) ◽  
pp. 1561a-1561
Author(s):  
J. Uppenbrink
Keyword(s):  
Self Assembly ◽  
Materials Science

scholarly journals Two-step crystallization and solid–solid transitions in binary colloidal mixtures

2020 ◽  
Vol 117 (45) ◽  
pp. 27927-27933
Author(s):  
Huang Fang ◽  
Michael F. Hagan ◽  
W. Benjamin Rogers
Keyword(s):  
Free Energy ◽  
Self Assembly ◽  
Materials Science ◽  
Protein Structures ◽  
Free Energy Barrier ◽  
Enhanced Sampling ◽  
Homogeneous Fluid ◽  
Metastable Structures ◽  
One Step ◽  
Crystal Phases

Crystallization is fundamental to materials science and is central to a variety of applications, ranging from the fabrication of silicon wafers for microelectronics to the determination of protein structures. The basic picture is that a crystal nucleates from a homogeneous fluid by a spontaneous fluctuation that kicks the system over a single free-energy barrier. However, it is becoming apparent that nucleation is often more complicated than this simple picture and, instead, can proceed via multiple transformations of metastable structures along the pathway to the thermodynamic minimum. In this article, we observe, characterize, and model crystallization pathways using DNA-coated colloids. We use optical microscopy to investigate the crystallization of a binary colloidal mixture with single-particle resolution. We observe classical one-step pathways and nonclassical two-step pathways that proceed via a solid–solid transformation of a crystal intermediate. We also use enhanced sampling to compute the free-energy landscapes corresponding to our experiments and show that both one- and two-step pathways are driven by thermodynamics alone. Specifically, the two-step solid–solid transition is governed by a competition between two different crystal phases with free energies that depend on the crystal size. These results extend our understanding of available pathways to crystallization, by showing that size-dependent thermodynamic forces can produce pathways with multiple crystal phases that interconvert without free-energy barriers and could provide approaches to controlling the self-assembly of materials made from colloids.

scholarly journals Lipid–oligonucleotide conjugates for bioapplications

2020 ◽  
Vol 7 (12) ◽  
pp. 1933-1953
Author(s):  
Xiaowei Li ◽  
Kejun Feng ◽  
Long Li ◽  
Lu Yang ◽  
Xiaoshu Pan ◽  
...  
Keyword(s):  
Self Assembly ◽  
Materials Science ◽  
Molecular Engineering ◽  
Dna Nanostructures ◽  
Future Directions ◽  
Intracellular Imaging ◽  
Cell Behaviors ◽  
Dna Strand ◽  
Oligonucleotide Conjugates ◽  
General Synthesis

Abstract Lipid–oligonucleotide conjugates (LONs) are powerful molecular-engineering materials for various applications ranging from biosensors to biomedicine. Their unique amphiphilic structures enable the self-assembly and the conveyance of information with high fidelity. In particular, LONs present remarkable potential in measuring cellular mechanical forces and monitoring cell behaviors. LONs are also essential sensing tools for intracellular imaging and have been employed in developing cell-surface-anchored DNA nanostructures for biomimetic-engineering studies. When incorporating therapeutic oligonucleotides or small-molecule drugs, LONs hold promise for targeted therapy. Moreover, LONs mediate the controllable assembly and fusion of vesicles based on DNA-strand displacements, contributing to nanoreactor construction and macromolecule delivery. In this review, we will summarize the general synthesis strategies of LONs, provide some characterization analysis and emphasize recent advances in bioanalytical and biomedical applications. We will also consider the relevant challenges and suggest future directions for building better functional LONs in nanotechnology and materials-science applications.

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