Puerckhauer, Korbinian and Weymouth, Alfred J. and Pfeffer, Katharina and Kullmann, Lars and Mulvihill, Estefania and Krahn, Michael P. and Muller, Daniel J. and Giessibl, Franz J. (2018) Imaging in Biologically-Relevant Environments with AFM Using Stiff qPlus Sensors. SCIENTIFIC REPORTS, 8: 9330. ISSN 2045-2322,
Full text not available from this repository. (Request a copy)Abstract
High-resolution imaging of soft biological samples with atomic force microscopy (AFM) is challenging because they must be imaged with small forces to prevent deformation. Typically, AFM of those samples is performed with soft silicon cantilevers (k approximate to 0.1-10 N/m) and optical detection in a liquid environment. We set up a new microscope that uses a stiff qPlus sensor (k >= 1 kN/m). Several complex biologically-relevant solutions are non-transparent, and even change their optical properties over time, such as the cell culture medium we used. While this would be problematic for AFM setups with optical detection, it is no problem for our qPlus setup which uses electrical detection. The high stiffness of the qPlus sensor allows us to use small amplitudes in frequency-modulation mode and obtain high Q factors even in liquid. The samples are immersed in solution in a liquid cell and long tips are used, with only the tip apex submerged. We discuss the noise terms and compare the minimal detectable signal to that of soft cantilevers. Atomic resolution of muscovite mica was achieved in various liquids: H2O, Tris buffer and a cell culture medium. We show images of lipid membranes in which the individual head groups are resolved.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | ATOMIC-FORCE MICROSCOPY; SUPPORTED LIPID-BILAYERS; QUARTZ TUNING FORK; OPTICAL MICROSCOPY; AMBIENT CONDITIONS; CHEMICAL-ANALYSIS; MODULATION; RESOLUTION; LIQUID; SPECTROSCOPY; |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Experimental and Applied Physics > Chair Professor Giessibl > Group Franz J. Giessibl |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 20 Feb 2020 08:16 |
| Last Modified: | 20 Feb 2020 08:16 |
| URI: | https://pred.uni-regensburg.de/id/eprint/14388 |
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