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Self-assembly Technique (self-assembly + technique)

Distribution by Scientific Domains

Chemistry	50%

Selected Abstracts

Large-scale, Uniform DNA Network on 11-mercaptoundecanoic Acid Modified Gold (111) Surface: Atomic Force Microscopy Study

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 7 2007
Yonghai Song
Abstract Large-scale, uniform plasmid deoxyribonucleic acid (DNA) network has been successfully constructed on 11-mercaptoundecanoic acid modified gold (111) surface using a self-assembly technique. The effect of DNA concentration on the characteristics of the DNA network was investigated by atomic force microscopy. It was found that the size of meshes and the height of fibers in the DNA network could be controlled by varying the concentration of DNA with a constant time of assembly of 24 h. Microsc. Res. Tech., 2007. © 2007 Wiley-Liss, Inc. [source]

Patterning of diverse mammalian cell types in serum free medium with photoablation

BIOTECHNOLOGY PROGRESS, Issue 2 2009
Vipra Dhir
Abstract Integration of living cells with novel microdevices requires the development of innovative technologies for manipulating cells. Chemical surface patterning has been proven as an effective method to control the attachment and growth of diverse cell populations. Patterning polyelectrolyte multilayers through the combination of layer-by-layer self-assembly technique and photolithography offer a simple, versatile, and silicon compatible approach that overcomes chemical surface patterning limitations, such as short-term stability and low-protein adsorption resistance. In this study, direct photolithographic patterning of two types of multilayers, PAA (poly acrylic acid)/PAAm (poly acryl amide) and PAA/PAH (poly allyl amine hydrochloride), were developed to pattern mammalian neuronal, skeletal, and cardiac muscle cells. For all studied cell types, PAA/PAAm multilayers behaved as a cytophobic surface, completely preventing cell attachment. In contrast, PAA/PAH multilayers have shown a cell-selective behavior, promoting the attachment and growth of neuronal cells (embryonic rat hippocampal and NG108-15 cells) to a greater extent, while providing little attachment for neonatal rat cardiac and skeletal muscle cells (C2C12 cell line). PAA/PAAm multilayer cellular patterns have also shown a remarkable protein adsorption resistance. Protein adsorption protocols commonly used for surface treatment in cell culture did not compromise the cell attachment inhibiting feature of the PAA/PAAm multilayer patterns. The combination of polyelectrolyte multilayer patterns with different adsorbed proteins could expand the applicability of this technology to cell types that require specific proteins either on the surface or in the medium for attachment or differentiation, and could not be patterned using the traditional methods. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source]

Triple Hydrogen Bonds Direct Crystal Engineering of Metal-Assembled Complexes: The Effect of a Novel Organic,Inorganic Module on Supramolecular Structure

CHEMISTRY - A EUROPEAN JOURNAL, Issue 22 2005
Keiichi Adachi Dr.
Abstract Novel triply hydrogen bonded suprastructures based on [M(tdpd)2(L)2]2, (H2tdpd=1,4,5,6-tetrahydro-5,6-dioxo-2,3-pyrazinedicarbonitrile, L=solvent) and melamine-analogous cations have been synthesized and characterized. The use of anions containing two AAA sets from [M(tdpd)2(L)2]2, together with cations containing one DDD set (A=hydrogen-bond acceptor, D=hydrogen-bond donor) leads to the formation of complementary triply hydrogen bonded modules in the solid state. In all cases, the building module is further extended via additional hydrogen-bonding interactions to produce a tape, and tapes are assembled into sheets. These results show that a hydrogen-bonded module consisting of different kinds of building blocks, one of which is a metal complex that includes hydrogen-bond acceptor sites and the other is a hydrogen-bond donor molecule, will be attractive for constructing metal-containing supramolecular systems by the self-assembly technique. [source]

Fabrication of Ultrathin Films with Large Third-Order Nonlinear Optical Properties

CHEMPHYSCHEM, Issue 3 2005
Li Jiang
Abstract An ultrathin composite film containing anionic Ag-His complexes (His: L -Histidine) and oppositely charged BH-PPV was fabricated by means of the electrostatic layer-by-layer self-assembly technique. UV/Vis spectra showed a continuous deposition process of Ag-His complexes and BH-PPV. The film structure was characterized by using small-angle X-ray diffraction, AFM, and SEM. The nonlinear optical properties of the ultrathin film were studied by using the Z -scan technique with a laser duration of 8 ns at a wavelength of 532 nm. The film sample exhibited a strong nonlinear saturated absorption, with an ,2value of ,3.9×10,5m,W,1and a self-defocusing effect with an n2value of ,4.78×10,12m2,W,1. [source]