Self-assembling layers created by membrane proteins on gold

2007 ◽  
Vol 35 (3) ◽  
pp. 522-526 ◽  
Author(s):  
D.S. Shah ◽  
M.B. Thomas ◽  
S. Phillips ◽  
D.A. Cisneros ◽  
A.P. Le Brun ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Self Assembly ◽  
Three Dimensions ◽  
Membrane Systems ◽  
Electrical Measurements ◽  
Supported Bilayers ◽  
Force Microscopy ◽  
Planar Surfaces ◽  
Self Assembling ◽  
Atomic Force

Membrane systems are based on several types of organization. First, amphiphilic lipids are able to create monolayer and bilayer structures which may be flat, vesicular or micellar. Into these structures membrane proteins can be inserted which use the membrane to provide signals for lateral and orientational organization. Furthermore, the proteins are the product of highly specific self-assembly otherwise known as folding, which mostly places individual atoms at precise places in three dimensions. These structures all have dimensions in the nanoscale, except for the size of membrane planes which may extend for millimetres in large liposomes or centimetres on planar surfaces such as monolayers at the air/water interface. Membrane systems can be assembled on to surfaces to create supported bilayers and these have uses in biosensors and in electrical measurements using modified ion channels. The supported systems also allow for measurements using spectroscopy, surface plasmon resonance and atomic force microscopy. By combining the roles of lipids and proteins, highly ordered and specific structures can be self-assembled in aqueous solution at the nanoscale.

Controlling neuronal growth and connectivity via directed self-assembly of proteins

2013 ◽  
Vol 1498 ◽  
pp. 207-212
Author(s):  
Daniel Rizzo ◽  
Ross Beighley ◽  
James D. White ◽  
Cristian Staii
Keyword(s):  
Self Assembly ◽  
Gold Surface ◽  
Nerve Tissue ◽  
3 Dimensional ◽  
Force Microscopy ◽  
Self Assembling ◽  
Atomic Force ◽  
Will Self ◽  
Neuron Growth

ABSTRACTMaterials that offer the ability to influence tissue regeneration are of vital importance to the field of Tissue Engineering. Because valid 3-dimensional scaffolds for nerve tissue are still in development, advances with 2-dimensional surfaces in vitro are necessary to provide a complete understanding of controlling regeneration. Here we present a method for controlling nerve cell growth on Au electrodes using Atomic Force Microscopy -aided protein assembly. After coating a gold surface in a self-assembling monolayer of alkanethiols, the Atomic Force Microscope tip can be used to remove regions of the self-assembling monolayer in order to produce well-defined patterns. If this process is then followed by submersion of the sample into a solution containing neuro-compatible proteins, they will self assemble on these exposed regions of gold, creating well-specified regions for promoted neuron growth.

scholarly journals Exploring the Self-Assembly of Encapsulin Protein Nanocages from Different Structural Classes

2021 ◽  
Author(s):  
India Boyton ◽  
Sophia C Goodchild ◽  
Dennis Diaz ◽  
Aaron Elbourne ◽  
Lyndsey Collins-Praino ◽  
...  
Keyword(s):  
Self Assembly ◽  
Structural Integrity ◽  
Guanidine Hydrochloride ◽  
Significant Loss ◽  
Spectroscopic Techniques ◽  
Design Modification ◽  
Force Microscopy ◽  
Future Design ◽  
Self Assembling ◽  
Atomic Force

Encapsulins, self-assembling icosahedral protein nanocages derived from prokaryotes, represent a versatile set of tools for nanobiotechnology. However, a comprehensive understanding of the mechanisms underlying encapsulin self-assembly, disassembly, and reassembly is lacking. Here, we characterise the disassembly/reassembly properties of three encapsulin nanocages that possess different structural architectures: T = 1 (24 nm), T = 3 (32 nm), and T = 4 (42 nm). Using spectroscopic techniques and electron microscopy, encapsulin architectures were found to exhibit varying sensitivities to the denaturant guanidine hydrochloride (GuHCl), extreme pH, and elevated temperature. While all encapsulins showed the capacity to reassemble following GuHCl-induced disassembly (within 75 min), only the smallest T = 1 nanocage reassembled after disassembly in basic pH (within 15 min). Furthermore, atomic force microscopy revealed that all encapsulins show a significant loss of structural integrity after undergoing sequential disassembly/reassembly steps. These findings provide insights into encapsulins disassembly/reassembly dynamics, thus informing their future design, modification, and application.

Combinatorial Approach to Materials Fabrication from Higher Hierarchies of Rosette Nanotubes

2007 ◽  
Vol 1057 ◽  
Author(s):  
Grigory Tikhomirov ◽  
Hicham Fenniri
Keyword(s):  
Electron Microscopy ◽  
Self Assembly ◽  
The Self ◽  
Combinatorial Approach ◽  
X Ray ◽  
Force Microscopy ◽  
Rosette Nanotubes ◽  
Self Assembling ◽  
Atomic Force ◽  
Transmission Electron

ABSTRACTThe self-assembly of six self-complimentary Guanine – Cytosine hybrid heterocycles bearing hydrophobic substituents has been studied using combinatorial approach in eight solvents under different conditions. The parameters that were varied include: the structure of the self-assembling module, its concentration, the solvent, temperature, and time of self-assembly. scanning electron microscopy (SEM) was used as a screening tool. A wide variety of interesting morphologies was found. The most interesting structures were studied by atomic force microscopy (AFM), transmission electron microscopy (TEM), dynamic light scattering (DLS), and X-ray powder diffraction (XRD).

Atomic Force Microscopy Studies of Alkyl-Phosphonate SAMs on Mica

2008 ◽  
Vol 589 ◽  
pp. 257-262 ◽  
Author(s):  
A. Paszternák ◽  
A. Pilbáth ◽  
Z. Keresztes ◽  
Ilona Felhősi ◽  
J. Telegdi ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Self Assembly ◽  
Ethanol Solution ◽  
Layer Formation ◽  
Mica Surface ◽  
Phosphonic Acids ◽  
Force Microscopy ◽  
Alkyl Chains ◽  
Self Assembling ◽  
Atomic Force

The layer formation of phosphonic acids on mica surface as a model system, from aqueous and ethanol solutions has been investigated. The aggregation behavior (critical micelle concentration, cmc) of molecules in the solution phase has been determined by surface tension measurements in order to select the appropriate concentration for the layer formation experiments. Layer formation of self-assembling molecules of alkyl-phosphonic acids has been followed by atomic force microscopy (AFM). Nucleation, growth and coalescence of densely packed islands of phosphonates from ethanol solution have been recorded on mica surface. The structure of islands depends on the length of alkyl-chains. Self-assembly of phosphonates has been also observed from aqueous solution, as presented by octyl-phosphonic acid (OcPA). The height of OcPA islands is 1.46 􀁲 0.22 nm, which is practically equal with the length of molecule (1.4 nm). This shows that OcPA molecules form monolayer height domains on the mica surface.

scholarly journals Polyaniline–nanodiamond fibers resulting from the self-assembly of nano-fibrils: a nanomechanical study

Nanoscale ◽  
2015 ◽  
Vol 7 (34) ◽  
pp. 14358-14367 ◽  
Author(s):  
Daniele Passeri ◽  
Emanuela Tamburri ◽  
Maria Letizia Terranova ◽  
Marco Rossi
Keyword(s):  
Atomic Force Microscopy ◽  
Self Assembly ◽  
The Self ◽  
Force Microscopy ◽  
Self Assembling ◽  
Atomic Force

Nanomechanical characterization of micrometric fibers of polyaniline (PANI) doped with nanodiamond (ND) particles resulting from the self-assembling of PANI/ND nano-fibrils has been performed using torsional harmonics atomic force microscopy.

scholarly journals Deposition of exchange-coupled dinickel complexes on gold substrates utilizing ambidentate mercapto-carboxylato ligands

2017 ◽  
Vol 8 ◽  
pp. 1375-1387 ◽  
Author(s):  
Martin Börner ◽  
Laura Blömer ◽  
Marcus Kischel ◽  
Peter Richter ◽  
Georgeta Salvan ◽  
...  
Keyword(s):  
Self Assembly ◽  
Density Functional ◽  
Ionization Mass ◽  
Temperature Dependent ◽  
Force Microscopy ◽  
X Ray Crystallography ◽  
Planar Surfaces ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Gold Substrates

The chemisorption of magnetically bistable transition metal complexes on planar surfaces has recently attracted increased scientific interest due to its potential application in various fields, including molecular spintronics. In this work, the synthesis of mixed-ligand complexes of the type [NiII 2L(L’)](ClO4), where L represents a 24-membered macrocyclic hexaazadithiophenolate ligand and L’ is a ω-mercapto-carboxylato ligand (L’ = HS(CH2)5CO2 − (6), HS(CH2)10CO2 − (7), or HS(C6H4)2CO2 − (8)), and their ability to adsorb on gold surfaces is reported. Besides elemental analysis, IR spectroscopy, electrospray ionization mass spectrometry (ESIMS), UV–vis spectroscopy, and X-ray crystallography (for 6 and 7), the compounds were also studied by temperature-dependent magnetic susceptibility measurements (for 7 and 8) and (broken symmetry) density functional theory (DFT) calculations. An S = 2 ground state is demonstrated by temperature-dependent susceptibility and magnetization measurements, achieved by ferromagnetic coupling between the spins of the Ni(II) ions in 7 (J = +22.3 cm−1) and 8 (J = +20.8 cm−1; H = −2JS1S2). The reactivity of complexes 6–8 is reminiscent of that of pure thiolato ligands, which readily chemisorb on Au surfaces as verified by contact angle, atomic force microscopy (AFM) and spectroscopic ellipsometry measurements. The large [Ni2L] tail groups, however, prevent the packing and self-assembly of the hydrocarbon chains. The smaller film thickness of 7 is attributed to the specific coordination mode of the coligand. Results of preliminary transport measurements utilizing rolled-up devices are also reported.

Silicon Surface Chemical Treatments in Oxide/Nitride Dielectric Stack Properties

2002 ◽  
Vol 716 ◽  
Author(s):  
D. Jacques ◽  
S. Petitdidier ◽  
J.L. Regolini ◽  
K. Barla
Keyword(s):  
Oxygen Content ◽  
Oxide Thickness ◽  
Morphological Data ◽  
Electrical Characteristics ◽  
Electrical Measurements ◽  
Chemical Cleaning ◽  
Force Microscopy ◽  
Chemical Treatments ◽  
Atomic Force ◽  
Interfacial Oxygen

AbstractOxide/Nitride dielectric stack is widely used as the standard dielectric for DRAM capacitors. The influence of the chemical cleaning prior to the stack formation has been studied in this work. As a result, morphological data such as stack surface roughness (Atomic Force Microscopy) and silicon nitride (SiN) incubation time for growth are comparable for all the studied cases on <Si>. However, Tof-SIMS exhibits different oxygen content at the Si/stack interface following the different chemical treatments. Electrical measurements show comparable C-V and I-V results, for the same Equivalent Oxide Thickness (same capacitance at strong accumulation i.e.-3V) while the different studied interfaces bring different interface states density with lower values for higher interfacial oxygen content. For DRAM applications, a clear improvement in electrical characteristics is obtained under low interfacial oxygen content conditions. Results are compared in embedded-DRAM cells for which we developed an industrially compatible dielectric deposition sequence to obtain minimum leakage current with maximum specific capacitance and no particular linking constraints.

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 Membrane fusion studied by colloidal probes

2021 ◽  
Vol 50 (2) ◽  
pp. 223-237 ◽  
Author(s):  
Hannes Witt ◽  
Filip Savić ◽  
Sarah Verbeek ◽  
Jörn Dietz ◽  
Gesa Tarantola ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Optical Tweezers ◽  
Three Dimensional ◽  
Biological Processes ◽  
Supported Membranes ◽  
Supported Bilayers ◽  
Force Microscopy ◽  
Advantages And Disadvantages ◽  
Atomic Force ◽  
Colloidal Probes

AbstractMembrane-coated colloidal probes combine the benefits of solid-supported membranes with a more complex three-dimensional geometry. This combination makes them a powerful model system that enables the visualization of dynamic biological processes with high throughput and minimal reliance on fluorescent labels. Here, we want to review recent applications of colloidal probes for the study of membrane fusion. After discussing the advantages and disadvantages of some classical vesicle-based fusion assays, we introduce an assay using optical detection of fusion between membrane-coated glass microspheres in a quasi two-dimensional assembly. Then, we discuss free energy considerations of membrane fusion between supported bilayers, and show how colloidal probes can be combined with atomic force microscopy or optical tweezers to access the fusion process with even greater detail.

Extending AFM Phase Image of Nanocomposite Structures to 3D using FIB

2012 ◽  
Vol 1421 ◽  
Author(s):  
Russell J. Bailey ◽  
Remco Geurts ◽  
Debbie J. Stokes ◽  
Frank de Jong ◽  
Asa H. Barber
Keyword(s):  
Phase Contrast ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Polymer Nanocomposite ◽  
Three Dimensions ◽  
Phase Image ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mechanical Information ◽  
Nanocomposite Structures

ABSTRACTThe mechanical behavior of nanocomposites is critically dependent on their structural composition. In this paper we use Focused Ion Beam (FIB) microscopy to prepare surfaces from a layered polymer nanocomposite for investigation using phase contrast atomic force microscopy (AFM). Phase contrast AFM provides mechanical information on the surface examined and, by combining with the sequential cross-sectioning of FIB, can extend the phase contract AFM into three dimensions.

Sign in / Sign up

Export Citation Format

Share Document