scholarly journals Study of the geometric and mechanical features of nanoparticles of various nature by atomic force microscopy in PeakForce QNM mode

2020 ◽  
pp. 143-148
Author(s):  
I. A. Chelnokova ◽  
B. V. Ronishenko ◽  
M. N. Starodubtseva
Keyword(s):  
Atomic Force Microscopy ◽  
Silver Nanoparticles ◽  
Free Surface ◽  
Surface Area ◽  
Nanosized Particles ◽  
Adhesion Forces ◽  
Biological Origin ◽  
Force Microscopy ◽  
Atomic Force ◽  
Free Surface Area

Objective: to identify the difference of the numerical values of parameters characterizing the geometric and mechanical (adhesive) properties of inorganic nanosized particles and nanosized particles of biological origin by atomic force microscopy using the mode of the mapping of surface features at nanosized resolution.Material and methods. Exosomes isolated from the blood of Af mice by the method of sequential ultracentrifugation were used as bionanoparticles. Silver nanoparticles were used as inorganic nanoparticles. The nanoparticles were scanned in air with the help of the BioScope Resolve (Bruker) atomic force microscope in the PeakForce QNM in Air mode with the recording of the maps of adhesion forces and imaging of the topography of the studied surfaces.Results. The silver nanoparticles and exosomes had similar but statistically different diameters (45.59 ± 1.04 nm and 41.25 ± 0.91 nm, р < 0.001 t-test). Nevertheless, the silver nanoparticles were characterized by higher values of both height and free surface area in comparison with the corresponding values of the exosome parameters. This leads to a higher value of the spreading ration for exosomes (the average ratio of diameter to height (d/h) was 11.78 for exosomes and 6.67 for nanoparticles (p < 0.001, Mann-Whitney U test) due to greater adhesion properties of the exosome membranes compared to the silver nanoparticles and a lower value of the ratio of the particle volume to its surface area. Averaged over the nanoscale areas of the nanoparticle surface, the adhesion forces of exosomes were higher (3.2 ± 0.57 nN) compared to those of silver nanoparticles (2.2 ± 0.03 nN, p < 0.05, Mann-Whitney U test).Conclusion. The differences in the parameters of the geometric (diameter, height, free surface area) and mechanical properties (adhesion forces) of the silver nanoparticles and exosomes have been revealed, which allows identifying and differentiating of these nanoparticles by the methods of atomic force microscopy during the study of complex biological fluids with possible content of both the types of nanoparticles.

Nanoscale adhesion forces between the fungal pathogen Candida albicans and macrophages

2016 ◽  
Vol 1 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Sofiane El-Kirat-Chatel ◽  
Yves F. Dufrêne
Keyword(s):  
Atomic Force Microscopy ◽  
Candida Albicans ◽  
Immune Cells ◽  
Fungal Pathogen ◽  
Fungal Pathogens ◽  
Adhesion Forces ◽  
Force Microscopy ◽  
Atomic Force

We establish atomic force microscopy as a new nanoscopy platform for quantifying the forces between fungal pathogens and immune cells.

Scaling Analysis of a- and poly-Si Surface Roughness by Atomic Force Microscopy

1994 ◽  
Vol 367 ◽  
Author(s):  
T. Yoshinobu ◽  
A. Iwamoto ◽  
K. Sudoh ◽  
H. Iwasaki
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Surface Area ◽  
Scaling Behavior ◽  
Linear Size ◽  
Scaling Analysis ◽  
Macroscopic Scale ◽  
Force Microscopy ◽  
Atomic Force ◽  
Roughness Exponent

AbstractThe scaling behavior of the surface roughness of a-and poly-Si deposited on Si was investigated by atomic force microscopy (AFM). The interface width W(L), defined as the rms roughness as a function of the linear size of the surface area, was calculated from various sizes of AFM images. W(L) increased as a power of L with the roughness exponent ∝ on shorter length scales, and saturated at a constant value of on a macroscopic scale. The value of roughness exponent a was 0.48 and 0.90 for a-and poly-Si, respectively, and σ was 1.5 and 13.6nm for 350nm-thick a-Si and 500nm-thick poly-Si, respectively. The AFM images were compared with the surfaces generated by simulation.

scholarly journals Particle Adhesion Measurements on Insect Wing Membranes Using Atomic Force Microscopy

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Gregory S. Watson ◽  
Bronwen W. Cribb ◽  
Jolanta A. Watson
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Area ◽  
Wing Surface ◽  
Silica Spheres ◽  
Wing Membrane ◽  
Insect Wing ◽  
Force Microscopy ◽  
Plant Matter ◽  
Atomic Force ◽  
Eurema Hecabe

Many insects have evolved refined self-cleaning membrane structuring to contend with an environment that presents a range of potential contaminates. Contamination has the potential to reduce or interfere with the primary functioning of the wing membrane or affect other wing cuticle properties, (for example, antireflection). Insects will typically encounter a variety of air-borne contaminants which include plant matter and soil fragments. Insects with relatively long or large wings may be especially susceptible to fouling due to the high-wing surface area and reduced ability to clean their extremities. In this study we have investigated the adhesion of particles (pollens and hydrophilic silica spheres) to wing membranes of the super/hydrophobic cicada (Thopha sessiliba), butterfly (Eurema hecabe), and the hydrophilic wing of flower wasp (Scolia soror). The adhesional forces with both hydrophobic insects was significantly lower for all particle types than the hydrophilic insect species studied.

scholarly journals A modular atomic force microscopy approach reveals a large range of hydrophobic adhesion forces among bacterial members of the leaf microbiota

2019 ◽  
Vol 13 (7) ◽  
pp. 1878-1882 ◽  
Author(s):  
Maximilian Mittelviefhaus ◽  
Daniel B. Müller ◽  
Tomaso Zambelli ◽  
Julia A. Vorholt
Keyword(s):  
Atomic Force Microscopy ◽  
Large Range ◽  
Adhesion Forces ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Adhesion force mapping on wood by atomic force microscopy: influence of surface roughness and tip geometry

2016 ◽  
Vol 3 (10) ◽  
pp. 160248 ◽  
Author(s):  
X. Jin ◽  
B. Kasal
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Wood Surface ◽  
Adhesion Force ◽  
Data Interpretation ◽  
Natural Fibre ◽  
Force Distribution ◽  
Adhesion Forces ◽  
Force Microscopy ◽  
Atomic Force

This study attempts to address the interpretation of atomic force microscopy (AFM) adhesion force measurements conducted on the heterogeneous rough surface of wood and natural fibre materials. The influences of wood surface roughness, tip geometry and wear on the adhesion force distribution are examined by cyclic measurements conducted on wood surface under dry inert conditions. It was found that both the variation of tip and surface roughness of wood can widen the distribution of adhesion forces, which are essential for data interpretation. When a common Si AFM tip with nanometre size is used, the influence of tip wear can be significant. Therefore, control experiments should take the sequence of measurements into consideration, e.g. repeated experiments with used tip. In comparison, colloidal tips provide highly reproducible results. Similar average values but different distributions are shown for the adhesion measured on two major components of wood surface (cell wall and lumen). Evidence supports the hypothesis that the difference of the adhesion force distribution on these two locations was mainly induced by their surface roughness.

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