25 November 2022

Séminaire ICP Cécile Formosa – vendredi 25 novembre à 14h

Cécile Formosa, Toulouse Biotechnology Institute, donnera un séminaire le vendredi 25 novembre 2022 à 14h en salle Magat

FluidFM developments to probe the interactions between air bubbles and (bio)-interfaces at the molecular scale

Abstract

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 recently developed a new method to probe more accurately the interactions between bubbles and (bio)-interfaces using FluidFM that combines AFM with microfluidic AFM probes. For that, microfluidic cantilevers were filled with air and immersed in a liquid environment. By applying a positive pressure inside these cantilevers, we succeeded in forming bubbles of controlled size directly at their aperture. 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 has proven to be a valuable tool in an application example where understanding how functionalized bubbles interact with microalgae cells allowed developing an original harvesting process.

25 November 2022, 14h0015h00
Salle Magat