A Cell's Perspective of its Culture Surface

2007 ◽  
Vol 1060 ◽  
Author(s):  
Ruchirej Yongsunthon ◽  
David E. Baker ◽  
Wendy A. Baker ◽  
Theresa Chang ◽  
Wanda J. Walczak ◽  
...  
Keyword(s):  
Culture Media ◽  
Preliminary Investigation ◽  
Surface Proteins ◽  
Force Microscopy ◽  
Driving Mechanisms ◽  
Atomic Force ◽  
Debye Shielding ◽  
Culture Surface ◽  
Substrate Surfaces ◽  
Functionalized Tips

ABSTRACTAtomic Force Microscopy (AFM) was employed to probe the internal structure of living HepG2/C3A cells grown on various commercially-available substrates. In order to understand the driving mechanisms behind the different cell morphologies, the surface properties of these substrates was characterized with AFM and related techniques. The roughness of a 10μm×10μm region of a series of substrates was determined and found to be independent of both coating and culture media, with the exception of thick hydrogel-like coatings. Probing with functionalized tips could not distinguish relative degrees of hydrophobicity under cell culture media, presumably because Debye shielding masks the substrate surfaces. Force spectroscopy was performed on the surfaces to determine exposed surface proteins/polymers intrinsic to the substrate and adsorbed from culture media. Preliminary investigation of cell-mediated substrate reconstruction suggests that the cells secrete large (1000kDa) polymeric molecules at the substrate interface.

scholarly journals Towards an Understanding of Crystallization by Attachment

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 463
Author(s):  
Haihua Pan ◽  
Ruikang Tang
Keyword(s):  
Capillary Condensation ◽  
Force Measurements ◽  
Force Microscopy ◽  
Physical Conditions ◽  
Driving Mechanisms ◽  
Atomic Force ◽  
Wide Range ◽  
Dynamics Simulations ◽  
Hydration Layers

Crystallization via particle attachment was used in a unified model for both classical and non-classical crystallization pathways, which have been widely observed in biomimetic mineralization and geological fields. However, much remains unknown about the detailed processes and driving mechanisms for the attachment. Here, we take calcite crystal as a model mineral to investigate the detailed attachment process using in situ Atomic Force Microscopy (AFM) force measurements and molecular dynamics simulations. The results show that hydration layers hinder the attachment; however, in supersaturated solutions, ionic bridges are formed between crystal gaps as a result of capillary condensation, which might enhance the aggregation of calcite crystals. These findings provide a more detailed understanding of the crystal attachment, which is of vital importance for a better understanding of mineral formation under biological and geological environments with a wide range of chemical and physical conditions.

scholarly journals Image correction for atomic force microscopy images with functionalized tips

2014 ◽  
Vol 89 (20) ◽  
Author(s):  
M. Neu ◽  
N. Moll ◽  
L. Gross ◽  
G. Meyer ◽  
F. J. Giessibl ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Image Correction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Functionalized Tips ◽  
Microscopy Images

scholarly journals In Situ Initial Growth Studies of SrTiO3 on SrTiO3 by Time Resolved High Pressure RHEED

1998 ◽  
Vol 526 ◽  
Author(s):  
Gertjan Koster ◽  
Guus J.H.M. Rijnders ◽  
Dave H.A. Blank ◽  
Horst Rogalla
Keyword(s):  
High Pressure ◽  
Pulsed Laser ◽  
High Energy ◽  
Initial Growth ◽  
Time Resolved ◽  
Force Microscopy ◽  
Atomic Force ◽  
Different Temperatures ◽  
Substrate Surfaces

AbstractThe initial growth of pulsed laser deposited SrTiO3 on SrTiO3 has been studied using high pressure Reflection High Energy Electron Diffraction (RHEED) and Atomic Force Microscopy (AFM). For this, we developed a Pulsed Laser Deposition (PLD)-RHEED system, with the possibility to study the growth and to monitor the growth rates, in situ, at typical PLD pressures (10-50 Pa). Using perfect single crystal SrTiO3 substrate surfaces, we observe true 2D intensity oscillations at different temperatures. Simultaneously, information on the diffusion of the deposited material on the surface could be extracted from the relaxation of the intensity after each laser pulse. The characteristic times depend on pressure and temperature as well as the 2D coverage during growth.

scholarly journals The mechanisms underlying the enhanced resolution of atomic force microscopy with functionalized tips

2010 ◽  
Vol 12 (12) ◽  
pp. 125020 ◽  
Author(s):  
Nikolaj Moll ◽  
Leo Gross ◽  
Fabian Mohn ◽  
Alessandro Curioni ◽  
Gerhard Meyer
Keyword(s):  
Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Enhanced Resolution ◽  
Functionalized Tips

In Vivo Atomic Force Microscopy of Surface Proteins onDeinococcus radiodurans

Langmuir ◽  
2001 ◽  
Vol 17 (9) ◽  
pp. 2624-2628 ◽  
Author(s):  
T. E. Lister ◽  
P. J. Pinhero
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Proteins ◽  
Force Microscopy ◽  
Atomic Force

Nucleation Mechanism for Epitaxial Graphene on Si-Terminated SiC (0001) Surfaces

2011 ◽  
Vol 338 ◽  
pp. 530-533
Author(s):  
Qing Bin Liu ◽  
Jia Li ◽  
Jing Jing Wang ◽  
Shao Bo Dun ◽  
Zhi Hong Feng
Keyword(s):  
Epitaxial Graphene ◽  
Nucleation Mechanism ◽  
Raman Scattering Spectrum ◽  
Force Microscopy ◽  
Atomic Force ◽  
Graphene Films ◽  
Scattering Spectrum ◽  
Initial Nucleation ◽  
Decomposition Time ◽  
Substrate Surfaces

The nucleation mechanism during the epitaxial graphene films on Si-terminated SiC (0001) surfaces was investigated by atomic force microscopy (AFM) and Raman scattering spectrum. By imaging the change of Si-terminated SiC substrate surfaces, we observed the process of the initial nucleation and the wrinkle formation of graphene. The nucleation of epitaxial graphene phase initiates at 1450°C and the wrinkle formation depends on the thermal decomposition time.

Sufficient condition for reliability measurement of sample geometry by atomic force microscopy

2020 ◽  
pp. 11-15
Author(s):  
Alexander S. Kravchuk ◽  
Anzhelika I. Kravchuk
Keyword(s):  
Atomic Force Microscopy ◽  
Preliminary Investigation ◽  
Sample Surface ◽  
Sufficient Condition ◽  
Surface Geometry ◽  
Force Microscopy ◽  
Atomic Force ◽  
Geometric Deviations ◽  
Reliability Measurement ◽  
Microscope Stage

A sufficient condition for determining the reliability of geometry measurements using atomic force microscopy for relatively small cantilever tilt angles is proposed. A relationship between the basic geometric parameters of surface roughness, geometric deviations of the probe, the angles of the cantilever and the inclination of the side faces of the probe, as well as the dimensions of the nonlocal point of the probable contact of its side faces with protrusions of roughness has been established. As a sufficient condition for the reliability of geometry measurements using atomic force microscopy, an obvious requirement is accepted. It determines the smallness of the ratio of the sizes of a nonlocal point to the distance between neighboring nonlocal points. Publications in which the measurement of surface nano-geometry of the samples does not indicate the roughness of the sample surface and the probe, the angles at the tip of the probe and the tilt of the cantilever, as well as the best resolution (smallest step) at which the study is carried out, cannot be accepted as reliable, because the results obtained in them are probabilistic in nature. The surface images obtained using atomic force microscopy without proper justification for the resolution (value of the measurement step) represent only a qualitative picture, on the basis of which it makes no sense to carry out any computational manipulations. In order to increase the reliability of measurements of surface geometry using atomic force microscopy, it is necessary to radically increase the accuracy of the manufacture of probes, as well as use probes with the smallest possible angle at the apex. In addition, it is necessary to make changes in the design of the atomic force microscopy. In particular, the automatic rotation of the microscope stage should be designed. It should provide closeness the probe axis direction to the normal to the average plane of the sample. This “integral” angle of rotation of the microscope stage is easily iteratively determined at the stage of preliminary investigation of the geometry of the surface of the sample. In this case, it will be necessary to geometrically increase the length of the cantilever so that the base extends beyond the limits of the sample.

scholarly journals Nitrous oxide as an effective AFM tip functionalization: a comparative study

2019 ◽  
Vol 10 ◽  
pp. 315-321 ◽  
Author(s):  
Taras Chutora ◽  
Bruno de la Torre ◽  
Pingo Mutombo ◽  
Jack Hellerstedt ◽  
Jaromír Kopeček ◽  
...  
Keyword(s):  
High Resolution ◽  
Density Functional ◽  
High Resolution Imaging ◽  
Functional Theory ◽  
Force Microscopy ◽  
Atomic Force ◽  
Resolution Imaging ◽  
Particle Adsorption ◽  
Metal Tip ◽  
Functionalized Tips

We investigate the possibility of functionalizing Au tips by N2O molecules deposited on a Au(111) surface and their further use for imaging with submolecular resolution. First, we characterize the adsorption of the N2O species on Au(111) by means of atomic force microscopy with CO-functionalized tips and density functional theory (DFT) simulations. Subsequently we devise a method of attaching a single N2O to a metal tip apex and benchmark its high-resolution imaging and spectroscopic capabilities using FePc molecules. Our results demonstrate the feasibility of high-resolution imaging. However, we find an inherent asymmetry of the N2O probe-particle adsorption on the tip apex, in contrast to a CO tip reference. These findings are consistent with DFT calculations of the N2O- and CO tip apexes.

Ultrathin Films of Oriented Bacteriorhodopsin: Nanostructured Films for Investigating the Primary Photoevent in Vision Processes

2001 ◽  
Vol 679 ◽  
Author(s):  
Rigoberto C. Advincula ◽  
Mi-kyoung Park
Keyword(s):  
Ultrathin Films ◽  
Supramolecular Assembly ◽  
Solid Substrate ◽  
Film Structure ◽  
Glass Electrode ◽  
Layer By Layer ◽  
Ph Change ◽  
Force Microscopy ◽  
Atomic Force ◽  
Substrate Surfaces

ABSTRACTIn this work, a protocol for investigating Bacteriorhodopsin (BR) biomimetic systems as ultrathin films is presented. BR is one of the most well studied proteins important for investigating the primary photo-event in vision processes. The use of macromolecular assembly approaches for deposition onto solid support substrates, e.g. SiOx, gold- or ITO-coated glass (electrode) provide advantages in that surface sensitive measurements can be used to correlate photocurrent generation, photoelectric response, pH change, chromophore behavior, etc. with protein orientation at interfaces. Membrane and protein morphology were correlated to measurements using surface sensitive techniques, such as atomic force microscopy (AFM), ellipsometry, quartz crystal microbalance (QCM), etc. on solid-substrate systems. These studies can lead to applications in optobioelectronic devices (biosensors) including patterning in transducer array configurations, where the film structure is important. Hybrid films are possible with supramolecular assembly approaches, e.g. adsorption of membrane with lipidbilayers. We report our initial results on highly ordered and oriented BR protein arrays of controlled thickness, layer order, and orientation. This was done primarily using the alternate polyelectrolyte deposition (APD) or layer-by-layer (LbL) approach to functionalize substrate surfaces.

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