Atomic force microscope characterization of self-assembly behaviors of cyclo[8] pyrrole on solid substrates

2017 ◽  
Vol 674 ◽  
pp. 151-156 ◽  
Author(s):  
Hai Xu ◽  
Siqi Zhao ◽  
Xiang Xiong ◽  
Jinzhi Jiang ◽  
Wei Xu ◽  
...  
Keyword(s):  
Atomic Force Microscope ◽  
Self Assembly ◽  
Atomic Force ◽  
Solid Substrates

Characterization of photosystem II with the atomic-force microscope

1992 ◽  
Vol 50 (2) ◽  
pp. 1146-1147
Author(s):  
Kathleen M. Marr ◽  
Mary K. Lyon
Keyword(s):  
Photosystem Ii ◽  
Atomic Force Microscope ◽  
Three Dimensional ◽  
Biologically Active ◽  
Atomic Force ◽  
Freeze Etching ◽  
Image Averaging ◽  
Oxygen Evolving ◽  
Averaging Techniques

Photosystem II (PSII) is different from all other reaction centers in that it splits water to evolve oxygen and hydrogen ions. This unique ability to evolve oxygen is partly due to three oxygen evolving polypeptides (OEPs) associated with the PSII complex. Freeze etching on grana derived insideout membranes revealed that the OEPs contribute to the observed tetrameric nature of the PSIl particle; when the OEPs are removed, a distinct dimer emerges. Thus, the surface of the PSII complex changes dramatically upon removal of these polypeptides. The atomic force microscope (AFM) is ideal for examining surface topography. The instrument provides a topographical view of individual PSII complexes, giving relatively high resolution three-dimensional information without image averaging techniques. In addition, the use of a fluid cell allows a biologically active sample to be maintained under fully hydrated and physiologically buffered conditions. The OEPs associated with PSII may be sequentially removed, thereby changing the surface of the complex by one polypeptide at a time.

Anin situatomic force microscope for normal-incidence nanofocus X-ray experiments

2016 ◽  
Vol 23 (5) ◽  
pp. 1110-1117 ◽  
Author(s):  
M. V. Vitorino ◽  
Y. Fuchs ◽  
T. Dane ◽  
M. S. Rodrigues ◽  
M. Rosenthal ◽  
...  
Keyword(s):  
Thin Film ◽  
Atomic Force Microscope ◽  
High Speed ◽  
Normal Incidence ◽  
Organic Thin Film ◽  
X Ray ◽  
Atomic Force ◽  
Synchrotron Beamlines

A compact high-speed X-ray atomic force microscope has been developed forin situuse in normal-incidence X-ray experiments on synchrotron beamlines, allowing for simultaneous characterization of samples in direct space with nanometric lateral resolution while employing nanofocused X-ray beams. In the present work the instrument is used to observe radiation damage effects produced by an intense X-ray nanobeam on a semiconducting organic thin film. The formation of micrometric holes induced by the beam occurring on a timescale of seconds is characterized.

Hydrogen-Bonding Layer Protecting Polyelectrolyte Capsules and Its Mechanical Property Study with Atomic Force Microscope

2008 ◽  
Vol 8 (6) ◽  
pp. 2996-3002 ◽  
Author(s):  
Liqin Ge ◽  
Xing Wang ◽  
Long Ba ◽  
Zhongze Gu
Keyword(s):  
Hydrogen Bonding ◽  
Atomic Force Microscope ◽  
Elastic Deformation ◽  
Self Assembly ◽  
Laser Scanning ◽  
Confocal Laser ◽  
Bonding Layer ◽  
Layer By Layer ◽  
Assembly Method ◽  
Atomic Force

The hydrogen-bonding multilayered polyelectrolyte capsules with sizes around 6 μm were fabricated by layer-by-layer self-assembly method. The morphology of the obtained capsules was observed with Scanning Electron Microscope (SEM), Confocal Laser Scanning Microscope (CLSM) and Atomic Force Microscope (AFM), respectively. The elastic properties of the capsules were studied with AFM. The capsule was pressed by cantilever with different lengths, a glass bead glued at the end of the cantilever. The force curves were measured on the capsule in air. The Young's modulus of the capsule was obtained (E = 170 MPa for the loading). Results show that this model can predict the elastic deformation of the microcapsule. The accuracy of the elastic deformation of polymer capsule can be ensured using a cantilever of mediate stiffness. Our results show that the existence of the hydrogen-bonding layer makes the multilayered polyelectrolyte harder in comparison with the pure multilayered polyelectrolyte capsules.

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.

scholarly journals Identification and nanomechanical characterization of the fundamental single-strand protofilaments of amyloid α-synuclein fibrils

2018 ◽  
Vol 115 (28) ◽  
pp. 7230-7235 ◽  
Author(s):  
Francesco Simone Ruggeri ◽  
Fabrizio Benedetti ◽  
Tuomas P. J. Knowles ◽  
Hilal A. Lashuel ◽  
Sergey Sekatskii ◽  
...  
Keyword(s):  
Single Molecule ◽  
Self Assembly ◽  
Amyloid Fibrils ◽  
Molecular Assembly ◽  
Single Strand ◽  
Force Microscopy ◽  
Atomic Force ◽  
Presynaptic Protein ◽  
Polypeptide Chains

The formation and spreading of amyloid aggregates from the presynaptic protein α-synuclein in the brain play central roles in the pathogenesis of Parkinson’s disease. Here, we use high-resolution atomic force microscopy to investigate the early oligomerization events of α-synuclein with single monomer angstrom resolution. We identify, visualize, and characterize directly the smallest elementary unit in the hierarchical assembly of amyloid fibrils, termed here single-strand protofilaments. We show that protofilaments form from the direct molecular assembly of unfolded monomeric α-synuclein polypeptide chains. To unravel protofilaments’ internal structure and elastic properties, we manipulated nanomechanically these species by atomic force spectroscopy. The single-molecule scale identification and characterization of the fundamental unit of amyloid assemblies provide insights into early events underlying their formation and shed light on opportunities for therapeutic intervention at the early stages of aberrant protein self-assembly.

scholarly journals Characterization of atomic force microscope probes at low temperatures

2003 ◽  
Vol 94 (6) ◽  
pp. 4210-4214 ◽  
Author(s):  
Alexandra Radenovic ◽  
Eva Bystrenova ◽  
Laurent Libioulle ◽  
Francesco Valle ◽  
George T. Shubeita ◽  
...  
Keyword(s):  
Atomic Force Microscope ◽  
Low Temperatures ◽  
Atomic Force
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