Extending the limits of direct force measurements : colloidal probes from sub-micron particles

Title data

Helfricht, Nicolas ; Mark, Andreas ; Dorwling-Carter, Livie ; Zambelli, Tomaso ; Papastavrou, Georg:
Extending the limits of direct force measurements : colloidal probes from sub-micron particles.
In: Nanoscale. Vol. 9 (2017) Issue 27 . - pp. 9491-9501.
ISSN 2040-3372
DOI: https://doi.org/10.1039/C7NR02226C

Official URL:

Abstract in another language

Direct force measurements by atomic force microscopy (AFM) in combination with the colloidal probe technique are widely used to determine interaction forces in colloidal systems. However, a number of limitations are still preventing a more universal applicability of this technique. Currently, one of the most significant limitations is that only particles with diameters of several micrometers can be used as probe particles. Here, we present a novel approach, based on the combination of nanofluidics and AFM (also referred to as FluidFM-technique), that allows to overcome this size limit and extend the size of suitable probe particles below diameters of 500 nanometers. Moreover, by aspiration of colloidal particles with a hollow AFM-cantilever, the immobilization process is independent of the particle's surface chemistry. Furthermore, the probe particles can be exchanged in situ. The applicability of the FluidFM-technique is demonstrated with silica particles, which are also the types of particles most often used for the preparation of colloidal probes. By comparing ‘classical’ colloidal probes, i.e. probes from particles irreversibly attached with glue, and various particle sizes aspirated by the FluidFM-technique, we can quantitatively evaluate the instrumental limits. Evaluation of the force profiles demonstrate that even for 500 nm silica particles the diffuse layer properties can be evaluated quantitatively. Therefore, direct force measurements on the level of particle sizes used in industrial formulations will become available in the future.

Further data

Item Type:	Article in a journal
Refereed:	Yes
Institutions of the University:	Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Chair Physical Chemistry II Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Former Professors > Chair Physical Chemistry II - Univ.-Prof. Dr. Andreas Fery Faculties Faculties > Faculty of Biology, Chemistry and Earth Sciences Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Chair Physical Chemistry II Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Former Professors
Result of work at the UBT:	Yes
DDC Subjects:	500 Science > 540 Chemistry
Date Deposited:	11 Sep 2017 08:28
Last Modified:	19 Oct 2022 11:35
URI:	https://eref.uni-bayreuth.de/id/eprint/39538