scholarly journals Measurement of Radial Elasticity and Original Height of DNA Duplex Using Tapping-Mode Atomic Force Microscopy

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 561 ◽  
Author(s):  
Longhai Li ◽  
Xu Zhang ◽  
Hongfei Wang ◽  
Qian Lang ◽  
Haitao Chen ◽  
...  

Atomic force microscopy (AFM) can characterize nanomaterial elasticity. However, some one-dimensional nanomaterials, such as DNA, are too small to locate with an AFM tip because of thermal drift and the nonlinearity of piezoelectric actuators. In this study, we propose a novel approach to address the shortcomings of AFM and obtain the radial Young’s modulus of a DNA duplex. The elastic properties are evaluated by combining physical calculations and measured experimental results. The initial elasticity of the DNA is first assumed; based on tapping-mode scanning images and tip–sample interaction force simulations, the calculated elastic modulus is extracted. By minimizing the error between the assumed and experimental values, the extracted elasticity is assigned as the actual modulus for the material. Furthermore, tapping-mode image scanning avoids the necessity of locating the probe exactly on the target sample. In addition to elasticity measurements, the deformation caused by the tapping force from the AFM tip is compensated and the original height of the DNA is calculated. The results show that the radial compressive Young’s modulus of DNA is 125–150 MPa under a tapping force of 0.5–1.3 nN; its original height is 1.9 nm. This approach can be applied to the measurement of other nanomaterials.

Soft Matter ◽  
2018 ◽  
Vol 14 (16) ◽  
pp. 3192-3201 ◽  
Author(s):  
Srinivas Mettu ◽  
Qianyu Ye ◽  
Meifang Zhou ◽  
Raymond Dagastine ◽  
Muthupandian Ashokkumar

Atomic Force Microscopy (AFM) is used to measure the stiffness and Young's modulus of individual microcapsules that have a chitosan cross-linked shell encapsulating tetradecane.


Nanoscale ◽  
2018 ◽  
Vol 10 (27) ◽  
pp. 13022-13027 ◽  
Author(s):  
Basant Chitara ◽  
Assaf Ya'akobovitz

The present study highlights the elastic properties of suspended GaS, GaSe and GaTe nanosheets using atomic force microscopy. GaS exhibited the highest Young's modulus (∼173 GPa) among these nanosheets. These materials can withstand maximal stresses of up to 8 GPa and a maximal strain of 7% before breaking, making them suitable for stretchable electronic and optomechanical devices.


2007 ◽  
Vol 334-335 ◽  
pp. 761-764
Author(s):  
D.H. Choi ◽  
C.W. Lee ◽  
P.S. Lee ◽  
J.H. Lee ◽  
W. Hwang ◽  
...  

Young’s modulus of nanohoneycomb structures in the vertical direction relative to the pore (generally along the beam length) is measured according to the porosity from bending tests in atomic force microscopy (AFM). The pore diameters of the nanohoneycomb structures are from about 30 to 60 nm. To determine the Young’s modulus of the nanohoneycomb structures, the area moment of inertia of the nanohoneycomb structure is determined according to the arrangement of the pores. The area moment of inertia of the nanohoneycomb structure is found to be affected by the porosity of the nanohoneycomb structures. The Young’s modulus of the nanohoneycomb structures decreases as a function of the porosity in a large range.


2021 ◽  
Vol 12 ◽  
pp. 1372-1379
Author(s):  
Xiaoteng Liang ◽  
Shuai Liu ◽  
Xiuchao Wang ◽  
Dan Xia ◽  
Qiang Li

The mechanical properties of cells are key to the regulation of cell activity, and hence to the health level of organisms. Here, the morphology and mechanical properties of normal pancreatic cells (HDPE6-C7) and pancreatic cancer cells (AsPC-1, MIA PaCa-2, BxPC-3) were studied by atomic force microscopy. In addition, the mechanical properties of MIA PaCa-2 after treatment with different concentrations of doxorubicin hydrochloride (DOX) were also investigated. The results show the Young's modulus of normal cells is greater than that of three kinds of cancer cells. The Young's modulus of more aggressive cancer cell AsPC-1 is smaller than that of less aggressive cancer cell BxPC-3. In addition, the Young's modulus of MIA PaCa-2 rises with the increasing of DOX concentration. This study may provide a new strategy of detecting cancer, and evaluate the possible interaction of drugs on cells.


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