scholarly journals Layer-by-Layer Encapsulation of Herbicide-Degrading Bacteria for Improved Surface Properties and Compatibility in Soils

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3814
Author(s):  
Reut Gal ◽  
Neriya Perez-Lapid ◽  
Yael Zvulunov ◽  
Adi Radian
Keyword(s):  
Surface Properties ◽  
Self Assembly ◽  
Chemical Properties ◽  
Polymeric Coating ◽  
Layer By Layer ◽  
Microscopy Imaging ◽  
E Coli ◽  
Degrading Bacteria ◽  
Herbicide Atrazine

E. coli cells overexpressing the enzyme atrazine chlorohydrolase were coated using layer-by-layer self-assembly. The polymeric coating was designed to improve the surface properties of the cells and create positively charged, ecologically safe, bio-hybrid capsules that can efficiently degrade the herbicide atrazine in soils. The physio-chemical properties of the bacteria/polymer interface were studied as a function of the polymeric composition of the shell and its thickness. Characterization of cell viability, enzyme activity, morphology, and size of the bio-capsules was done using fluorescence spectroscopy, BET and zeta potential measurements and electron microscopy imaging. Out of several polyelectrolytes, the combination of polydiallyldimethylammonium chloride and polysodium 4-styrenesulfonate improved the surface properties and activity of the cells to the greatest extent. The resulting bio-hybrid capsules were stable, well-dispersed, with a net positive charge and a large surface area compared to the uncoated bacteria. These non-viable, bio-hybrid capsules also exhibited a kinetic advantage in comparison with uncoated cells. When added to soils, they exhibited continuous activity over a six-week period and atrazine concentrations declined by 84%. Thus, the concept of layer-by-layer coated bacteria is a promising avenue for the design of new and sustainable bioremediation and biocatalytic platforms.

Preparation and Characterization of Nano-Films Materials

2011 ◽  
Vol 492 ◽  
pp. 160-163
Author(s):  
Cai Xia Li ◽  
Qing Lv ◽  
Jie Song ◽  
Dan Yu Jiang ◽  
Qiang Li
Keyword(s):  
Self Assembly ◽  
Chemical Properties ◽  
Layered Compounds ◽  
Insertion Reaction ◽  
Layer By Layer ◽  
Vis Spectroscopy ◽  
Assembly Technique ◽  
Assembly Technology ◽  
Physical And Chemical

Nano-sheets are two-dimensional sheet materials exfoliated from the inorganic layered compounds by various physical and chemical methods. Their unique characteristics insertion reaction and excellent physical and chemical properties have attracted more and more researchers' widespread interests. Selecting quartz glass as the substrate, using layer by layer self-assembly technology, different nano-films materials are prepared. UV/Vis spectroscopy confirmed nano-films materials have been successfully assembled using LBL self-assembly technique. Raman spectrum are mainly used to analyze and characterize the structure of nano-films materials.

scholarly journals Direct Patterning and Spontaneous Self-Assembly of Graphene Oxide via Electrohydrodynamic Jet Printing for Energy Storage and Sensing

Micromachines ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 13 ◽  
Author(s):  
Bin Zhang ◽  
Jaehyun Lee ◽  
Mincheol Kim ◽  
Naeeung Lee ◽  
Hyungdong Lee ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Energy Storage ◽  
Self Assembly ◽  
High Performance ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Layer By Layer ◽  
Energy Storage Devices ◽  
Laminar Structure ◽  
Jet Printing

The macroscopic assembly of two-dimensional materials into a laminar structure has received considerable attention because it improves both the mechanical and chemical properties of the original materials. However, conventional manufacturing methods have certain limitations in that they require a high temperature process, use toxic solvents, and are considerably time consuming. Here, we present a new system for the self-assembly of layer-by-layer (LBL) graphene oxide (GO) via an electrohydrodynamic (EHD) jet printing technique. During printing, the orientation of GO flakes can be controlled by the velocity distribution of liquid jet and electric field-induced alignment spontaneously. Closely-packed GO patterns with an ordered laminar structure can be rapidly realized using an interfacial assembly process on the substrates. The surface roughness and electrical conductivity of the LBL structure were significantly improved compared with conventional dispensing methods. We further applied this technique to fabricate a reduced graphene oxide (r-GO)-based supercapacitor and a three-dimensional (3D) metallic grid hybrid ammonia sensor. We present the EHD-assisted assembly of laminar r-GO structures as a new platform for preparing high-performance energy storage devices and sensors.

scholarly journals Morphometric characterization of fibrinogen's αC regions and their role in fibrin self-assembly and molecular organization

Nanoscale ◽  
2017 ◽  
Vol 9 (36) ◽  
pp. 13707-13716 ◽  
Author(s):  
Anna D. Protopopova ◽  
Rustem I. Litvinov ◽  
Dennis K. Galanakis ◽  
Chandrasekaran Nagaswami ◽  
Nikolay A. Barinov ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Self Assembly ◽  
Molecular Organization ◽  
Microscopy Imaging ◽  
Force Microscopy ◽  
Atomic Force ◽  
Atomic Force Microscopy Imaging ◽  
Morphometric Characterization

High-resolution atomic force microscopy imaging reveals the role of fibrinogen αC regions in the early stages of fibrin self-assembly.

Dumbbell-shaped dendrimers — Synthesis and self-assembly

2008 ◽  
Vol 86 (6) ◽  
pp. 540-547 ◽  
Author(s):  
Tatiana Vassilieff ◽  
Ashok Kakkar
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Layer By Layer ◽  
Acid Base ◽  
Detailed Characterization ◽  
Generation Number ◽  
Backbone Structure

We report on the synthesis and detailed characterization of dendrimers that evolve symmetrically from a linear core of 2-butyne-1,4-diol with 3,5-dihydroxybenzyl alcohol based dendron arms. The divergent layer-by-layer build-up of the dumbbell-shaped dendrimers is based on simple acid–base hydrolytic chemistry of bis(dimethylamino)dimethylsilane with OH-terminated molecules. The self-assembly of these dendrimers in THF and water is significantly influenced by their generation number, the backbone structure, and the solvent.Key words: dendrimers, divergent synthesis, macromolecules, self-assembly

Preparation and characterization of polymeric thin films containing gold nanoshells via electrostatic layer-by-layer self-assembly

2014 ◽  
Vol 558 ◽  
pp. 200-207 ◽  
Author(s):  
Sang Ho Lee ◽  
Andrew C. Jamison ◽  
David M. Hoffman ◽  
Allan J. Jacobson ◽  
T. Randall Lee
Keyword(s):  
Thin Films ◽  
Self Assembly ◽  
Gold Nanoshells ◽  
Layer By Layer ◽  
Polymeric Thin Films

scholarly journals Characterization of cytochrome bo3 activity in a native-like surface-tethered membrane

2008 ◽  
Vol 417 (2) ◽  
pp. 555-560 ◽  
Author(s):  
Sophie A. Weiss ◽  
Richard J. Bushby ◽  
Stephen D. Evans ◽  
Peter J. F. Henderson ◽  
Lars J. C. Jeuken
Keyword(s):  
Self Assembly ◽  
Membrane System ◽  
Terminal Oxidase ◽  
E Coli ◽  
Cytochrome Bo3 ◽  
Substrate Analogues ◽  
Long Chain ◽  
Good Agreement ◽  
Tethered Membranes

We have developed a simple native-like surface-tethered membrane system to investigate the activity of cbo3 (cytochrome bo3), a terminal oxidase in Escherichia coli. The tethered membranes consist of E. coli inner-membrane extracts mixed with additional E. coli lipids containing various amounts of the cbo3 substrate UQ-10 (ubiquinol-10). Tethered membranes are formed by self-assembly from vesicles on to gold electrodes functionalized with cholesterol derivatives. cbo3 activity was monitored using CV (cyclic voltammetry) with electron transfer to cbo3 mediated by UQ-10. The apparent Km for oxygen with this system is 1.1±0.4 μM, in good agreement with values reported in the literature for whole-cell experiments and for purified cbo3. Increasing the concentration of lipophilic UQ-10 in the membrane leads to an increase in cbo3 activity. The activity of cbo3 with long-chain ubiquinones appears to be different from previous reports using short-chain substrate analogues such as UQ-1 in that typical Michaelis–Menten kinetics are not observed using UQ-10. This native-like membrane model thus provides new insights into the interaction of transmembrane enzymes with hydrophobic substrates which contrasts with studies using hydrophilic UQ analogues.

DYNAMIC BEHAVIOR OF METHYLENE BLUE ON E. coli K30 CAPSULAR POLYSACCHARIDE USING LAYER BY LAYER SELF-ASSEMBLY TECHNIQUE

2020 ◽  
pp. 2050027
Author(s):  
BANDANA DAS ◽  
ALPANA BAIDYA ◽  
SANTANU MAJUMDER ◽  
RANENDU KUMAR NATH
Keyword(s):  
Thin Film ◽  
Methylene Blue ◽  
Dynamic Behavior ◽  
Self Assembly ◽  
Capsular Polysaccharide ◽  
Layer By Layer ◽  
Cationic Dye ◽  
Bacterial Polysaccharide ◽  
E Coli ◽  
Assembly Technique

Layer-by-layer (LbL) self-assembly is one of the unique methods for fabrication of ultra-thin film. This technique has immense application aross many fields in today’s life. In this paper, we have presented the fabrication of the thin film comprising of antifungal and antibacterial cationic dye methylene blue with negatively charged E. coli K30 bacterial polysaccharide sharing with PAH. The multilayers were characterized by UV–Vis absorption spectra and AFM. Various photophysical behaviors were investigated. Such studies provide a new light in the research of layer by layer self-assembly technique.

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