Probing the interactions between air bubbles and (bio)-interfaces at the molecular scale using FluidFM

Proposed by Cécile Formosa-Dague

Understanding the molecular mechanisms underlying bubble-(bio)surfaces interactions is currently a challenge that if overcame, would allow to understand and control the various processes in which they are involved. Atomic force microscopy is a valuable tool to measure such interactions, but it is limited by the large size and instability of bubbles that can be attached on surfaces or on AFM cantilevers. To overcome these challenges, we here develop a new method to probe more accurately the interactions between bubbles and (bio)-interfaces using FluidFM, where microsized bubbles of 8 µm in diameter are directly formed at the aperture of microchanneled FluidFM cantilevers. For that, instead of liquid, the cantilever is filled with air and immersed in a liquid environment. By applying a positive pressure inside the cantilever, we succeeded in forming bubbles of controlled size directly at its aperture. Because the same pressure is maintained in the cantilever during the experiment, the dissolution of the gases from the bubble is compensated, which allows keeping the size of the bubble constant over time. After the characterization of the bubbles produced using this method, their interactions with hydrophobic surfaces were probed, showing that bubbles behave like hydrophobic surfaces. Thus they were used to measure the hydrophobic properties of microorganisms’ surfaces, but in this case the interactions are also influenced by electrostatic forces. Finally we developed a strategy to functionalize their surface, thereby modulating their interactions with microorganisms’ surfaces. This new method provides a valuable tool to understand bubble-(bio)surfaces interactions but also to engineer them.

Reference:
Demir I. et al., 2021, Journal of Colloid and Interface Science, 604 (785-797). 

Irem DEMIR1,2,*, Ines LÜCHTEFELD3, Claude LEMEN1, Etienne DAGUE2,4, Pascal GUIRAUD1,4,Tomaso ZAMBELLI3, and Cécile FORMOSA-DAGUE1,4
1 TBI, Université de Toulouse, INSA, INRAE, CNRS, Toulouse, France
2 LAAS, Université de Toulouse, CNRS, Toulouse, France
3 Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland
4 Fédération de Recherche Fermat, CNRS, Toulouse, France


About The Speaker

INSA - TBI (M.F. Albert), C├ęcile Formosa-Dague

Cécile Formosa-Dague

CNRS researcher, TBI, INSA de Toulouse, France

Practical Info

Date
Dec 01, 2021 10:25 AM (Europe/Zurich)
Duration
20 minutes
Location
Digital