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Quantitative and Qualitative Examination of Particle-particle Interactions Using Colloidal Probe Nanoscopy
Published on: July 18, 2014
Exchangeable colloidal AFM probes for the quantification of irreversible and long-term interactions
Pablo Dörig1, Dario Ossola, Anh Minh Truong
1Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland.
Biophysical Journal
|July 23, 2013
Summary
A novel atomic force microscopy method allows precise measurement of single colloid interactions with surfaces in liquid. This technique enables detailed study of adhesion, long-term effects, and irreversible interactions, advancing materials science and cell adhesion research.
Area of Science:
- Materials Science
- Biophysics
- Surface Chemistry
Background:
- Understanding single-colloid interactions with substrates is crucial for various scientific fields.
- Existing methods for studying colloid-surface interactions can be limited in flexibility and scope.
Purpose of the Study:
- To present an original method for studying single-colloid interactions with substrates in a liquid environment.
- To enable quick variation of colloid functionalization, investigation of long-term interactions, and inspection of irreversible interactions.
Main Methods:
- A microchanneled atomic force microscopy (AFM) cantilever is used to fix single colloids via suction.
- Adhesion forces are measured, followed by colloid release using an overpressure surge.
- The method was validated by reproducing literature results and applied to micropatterned surfaces and cell adhesion studies.
Main Results:
- The method successfully reproduced established colloidal AFM results.
- Serial use of differently functionalized colloids on micropatterned surfaces was demonstrated.
- Adhesion forces between concanavalin A-coated colloids and human embryonic kidney cells were measured (up to 60 nN).
- Individual cell adhesion to glass substrate was measured (20 nN).
- A cellular elastic modulus of 0.8 kPa was determined.
Conclusions:
- The presented method offers a versatile and efficient approach for studying single-colloid interactions.
- It provides valuable insights into cell-colloid adhesion and allows for mechanical property determination of biological cells.
