Electrostatic self-assembly layer-by-layer film fabrication using a polycation and a phthalocyanine dye anion

2006 ◽  
Vol 10 (07) ◽  
pp. 986-990
Author(s):  
Young-A Son ◽  
Young-Min Park ◽  
Byung-Soon Kim
Keyword(s):  
Self Assembly ◽  
Copper Phthalocyanine ◽  
The Self ◽  
Layer By Layer ◽  
Layer Film ◽  
Force Microscopy ◽  
Atomic Force ◽  
Diallyldimethylammonium Chloride ◽  
Film Fabrication ◽  
Multi Layer Film

A multi-layer film has been fabricated, using poly(diallyldimethylammonium chloride) ( PDDAC ) and a copper phthalocyanine ( CuPc ) dye, held together by electrostatic forces and layer-by-layer self-assembly attractions. The result of the multi-layer fabrication was characterized by UV-vis absorbance measurements and Atomic Force Microscopy (AFM). UV-vis absorption spectra of the multi-layer films increased linearly at 676 nm, which indicated that the fabrication proceeded regularly. The AFM images show that the surface of the self-assembled multi-layer was thickly covered with PDDAC / CuPc and relatively uniform.

Self-assembly layer-by-layer fabrication using porphyrin dye anion and polycation

2009 ◽  
Vol 13 (07) ◽  
pp. 774-778 ◽  
Author(s):  
Byung-Soon Kim ◽  
Young-A Son
Keyword(s):  
Ultrathin Films ◽  
Self Assembly ◽  
Film Surface ◽  
Layer By Layer ◽  
Preparation Technique ◽  
Force Microscopy ◽  
Atomic Force ◽  
Diallyldimethylammonium Chloride ◽  
Afm Analysis ◽  
Progressive Growth

In this study, self-assembled alternating film using poly(diallyldimethylammonium chloride) (PDDAC) and meso-tetrakis(4-carboxyphenyl)porphyrin (MTCP) was prepared as a multilayer deposition on glass substrate. This preparation technique for dye deposition may provide new feasibilities to achieve the manufacture of ultrathin films for nanotechnology application. The deposition films were characterized by UV-vis spectrophotometer and Atomic Force Microscopy (AFM) analysis. The results of UV-vis spectra showed that the absorbance characteristic of the multilayer films linearly increased with an increased number of PDDAC and MTCP bilayers. AFM analysis showed the film surface was relatively uniform and the progressive growth of layers was determined.

Dynamic Self-Assembly Process of a Designed Peptide

2013 ◽  
Vol 750-752 ◽  
pp. 1630-1634
Author(s):  
Li Ping Ruan ◽  
Zhi Hua Xing
Keyword(s):  
Atomic Force Microscopy ◽  
Self Assembly ◽  
The Self ◽  
Layer By Layer ◽  
Assembly Process ◽  
Force Microscopy ◽  
Atomic Force ◽  
Sheet Structure ◽  
Β Sheet ◽  
Layer Assembly

In this paper, we reported the dynamic self-assembly process of an half-sequence ionic self-complementarity peptide CH3CO-Pro-Ser-Phe-Cys-Phe-Lys-Phe-Glu-Pro-NH2, which could self-assemble into stable nanofibers and formed hydrogel consisting of >99% water. The dynamic self-assembly process was detected by circular dichroism (CD) and atomic force microscopy (AFM). CD spectrum revealed that the mainly contents of the peptide were regular β-sheet structure. The data indicated that though the secondary structure of the peptide formed immediately, the microstructure of the self-assembly process of the designed peptide formed slowly. AFM image illustrated that the self-assembly process was layer-by-layer assembly.

Clathrin-Inspired Coating and Stabilization of Liposomes by DNA Self-Assembly

2019 ◽  
Author(s):  
Kevin N. Baumann ◽  
Luca Piantanida ◽  
Javier García-Nafría ◽  
Diana Sobota ◽  
Kislon Voïtchovsky ◽  
...  
Keyword(s):  
Self Assembly ◽  
Mechanical Stability ◽  
Lipid Vesicles ◽  
The Self ◽  
Force Microscopy ◽  
Atomic Force ◽  
Cryo Electron Microscopy ◽  
Further Development ◽  
Liposome Surface ◽  
Dna Coating

The self-assembly of the protein clathrin on biological membranes facilitates essential processes of endocytosis in biological systems and has provided a source of inspiration for materials design by the highly ordered structural appearance. By mimicking the architecture of clathrin self-assemblies to coat liposomes with biomaterials, new classes of hybrid carriers can be derived. Here we present a method for fabricating DNA-coated liposomes by hydrophobically anchoring and subsequently growing a DNA network on the liposome surface which structurally mimics clathrin assemblies. Dynamic light scattering (DLS), ζ-potential and cryo-electron microscopy (cryo-EM) measurements independently demonstrate successful DNA coating. Nanomechanical measurements conducted with atomic force microscopy (AFM) show that the DNA coating enhances the mechanical stability of the liposomes relative to uncoated ones. Furthermore, we provide the possibility to reverse the coating process by triggering the disassembly of the DNA coating through a toehold-mediated displacement reaction. Our results describe a straightforward, versatile, and reversible approach for coating and stabilizing lipid vesicles by an interlaced DNA network. This method has potential for further development towards the ordered arrangement of tailored functionalities on the surfaces of liposomes and for applications as hybrid nanocarrier.

scholarly journals Fabrication and Characterization of Antibacterial-active Multilayer Films Based on Keggin Polyoxometalates and Methylene Blue

2010 ◽  
Vol 65 (2) ◽  
pp. 140-146 ◽  
Author(s):  
Dan Chen ◽  
Jun Peng ◽  
Haijun Pang ◽  
Pengpeng Zhang ◽  
Yuan Chen ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Self Assembly ◽  
Multilayer Films ◽  
Photoelectron Spectra ◽  
Layer By Layer ◽  
Force Microscopy ◽  
Atomic Force ◽  
Assembly Technique ◽  
Lbl Films ◽  
Cv Measurements

Two kinds of multilayer films based on Keggin polyoxometalates α-[SiW12O40]4−/α- [PMo12O40]3− and methylene blue have been prepared via the layer-by-layer (LBL) self-assembly technique. The multilayer films were characterized by UV/Vis spectra, atomic force microscopy (AFM) and X-ray photoelectron spectra (XPS). The cyclic voltammetry (CV) measurements have demonstrated that the electrochemical properties of POMs are maintained in the LBL films. The antibacterial activity of the LBL films has also been investigated, which shows a distinct antibacterial effect against Escherichia coli.

NANOSTRUCTURES FROM DESIGNER PEPTIDES

COSMOS ◽  
2008 ◽  
Vol 04 (02) ◽  
pp. 173-183
Author(s):  
BOON TEE ONG ◽  
PARAYIL KUMARAN AJIKUMAR ◽  
SURESH VALIYAVEETTIL
Keyword(s):  
Atomic Force Microscopy ◽  
Solid State ◽  
Self Assembly ◽  
Size Range ◽  
The Self ◽  
Mica Surface ◽  
Force Microscopy ◽  
Solution Structures ◽  
Atomic Force

The present article reviews the self-assembly of oligopeptides to form nanostructures, both in solution and in solid state. The solution structures of the peptides were examined using circular dichroism and dynamic light scattering. The solid state assembly was examined by adsorbing the peptides onto a mica surface and analyzing it using atomic force microscopy. The role of pH and salt concentration on the peptide self-assembly was also examined. Nanostructures within a size range of 3–10 nm were obtained under different conditions.

scholarly journals Cation-Specific Effects on the Self-Assembly of Collagen Molecules Mediated by Acetate on Mica Surface Observed with Atomic Force Microscopy

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Zhiwei Wang ◽  
Qi Xiao ◽  
Xuan Song ◽  
Yunfei Wan ◽  
Jie Zhu
Keyword(s):  
Atomic Force Microscopy ◽  
Self Assembly ◽  
Ionic Concentration ◽  
Collagen Fibrils ◽  
The Self ◽  
Mica Surface ◽  
Force Microscopy ◽  
Specific Effects ◽  
Atomic Force ◽  
Base Method

The well-organized collagen layers on mica surface have drawn extensive attention for its essential applications and studies on the process of self-assembly as a model system. In this work, collagen extracted from fish scales by acid-base method was used to explore the self-assembly characters, and atomic force microscopy was applied to observe the collagen assembled on mica surface mediated by acetate with four different cations, including K+, Na+, Mg2+, and Ca2+. It showed that cations might influence the interaction between collagen fibrils and mica surface at high ionic concentration. And a similar network structure was acquired with uniform pore size for four kinds of acetates; nearly ranged collagen fibrils in the same direction were collected in Mg2+ solutions, while flat films with some fibrils were achieved in K+ solutions. The Hofmeister series and Collins’ model were adapted to explain the effects of cations and acetate on the self-assembly of collagen. These results and analysis would be helpful for directing the pattern of collagen assembly on a solid surface with a potential application in food science and engineering.

scholarly journals Self-assembly and wetting properties of gold nanorod–CTAB molecules on HOPG

2019 ◽  
Vol 10 ◽  
pp. 696-705 ◽  
Author(s):  
Imtiaz Ahmad ◽  
Floor Derkink ◽  
Tim Boulogne ◽  
Pantelis Bampoulis ◽  
Harold J W Zandvliet ◽  
...  
Keyword(s):  
Self Assembly ◽  
Cetyltrimethylammonium Bromide ◽  
Pyrolytic Graphite ◽  
The Self ◽  
Gold Nanorod ◽  
Force Microscopy ◽  
Wetting Properties ◽  
Atomic Force ◽  
Highly Ordered Pyrolytic Graphite ◽  
Self Assembled

The formation of self-assembled superstructures of cetyltrimethylammonium bromide (CTAB) after drying on a nonwetting highly ordered pyrolytic graphite (HOPG) surface have been investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Although SEM did not reveal coverage of CTAB layers, AFM showed not only CTAB assembly, but also the dynamics of the process on the surface. The self-assembled layers of CTAB molecules on the HOPG terraces prior to nanorod deposition were shown to change the wettability of the surface, and as a result, gold nanorod deposition takes place on nonwetting HOPG terraces.

Layer-by-Layer Thin Films of Alginate/Chitosan and Hyaluronic Acid/Chitosan with Tunable Thickness and Surface Roughness

2014 ◽  
Vol 783-786 ◽  
pp. 1226-1231 ◽  
Author(s):  
Thiago Bezerra Taketa ◽  
Marisa Masumi Beppu
Keyword(s):  
Thin Films ◽  
Hyaluronic Acid ◽  
Self Assembly ◽  
Polymer Chains ◽  
Layer By Layer ◽  
Natural Polymers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Polyelectrolyte Solutions ◽  
Oppositely Charged

Layer-by-layer (LbL) is a bottom-up technique used for construction of films with self-assembly and self-organizing properties. In most cases, the fundamental driving force for the formation of these films is originated from the electrostatic interaction between oppositely charged species. The charged segments of polyelectrolytes behave as small building units and their orientation and position can be designed to target structures of great complexity. Furthermore, the technique enables the use of various materials, including natural polymers. In this work, we chose the cationic biopolymer chitosan (CHI) and the negative polyelectrolytes sodium alginate (ALG) and hyaluronic acid (HA). The aim of this study was to evaluate the effect of ionic strength (0 versus 200 mM) and pH (3 versus 5) on ALG/CHI and HA/CHI nanostructured multilayered thin films properties. From profilometry and atomic force microscopy (AFM) analyses, changes in thickness and roughness of the coatings were monitored. The presence of salt in polyelectrolyte solutions induced the polymer chains to adopt conformations with more loops and tails and this arrangement in solution was transmitted to films, resulting in rougher surfaces. Furthermore, the film thickness can be precisely controlled by adjusting the pH of the polyelectrolyte solution. The variation of these parameters shows that it is possible to molecularly control chemical and structural properties of nanostructured coatings, thus opening up new possibilities of application (e.g. cell adhesion).

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