Probing the interactions between air bubbles and (bio)interfaces at the nanoscale using FluidFM technology

The Biophysical Properties of Microalgal Cell Surfaces Govern Their Interactions with an Amphiphilic Chitosan Derivative Used for Flocculation and Flotation

“…20 In particular, in this work, we used a combination of AFM with microfluidics (FluidFM 24 ) to produce functionalized microsized bubbles and measure their interactions at the molecular level with cells, using recent developments of our team. 25 These experiments allowed us to show that the functionalization of bubbles with PO-chitosan allowed significant increase in their interactions with C. vulgaris cells (CCAP strain 211/11B) in a pHdependent manner. However, the force curves obtained showed that hydrophobicity was the dominant component of the interaction between cells and functionalized bubbles, possibly because this particular C. vulgaris strain presents hydrophobic properties, and probably hiding the first and expected specific interaction between the chitosan backbone on the bubble surface and cells.…”

Combining AFM, XPS and chemical hydrolysis to understand the complexity and dynamics of C. vulgaris cell wall composition and architecture

“…Hydrophobicity measurements. Hydrophobicity measurements were conducted using AFM and FluidFM as described in Demir et al [27] Briefly, an air-bubble was produced using a Nanowizard III AFM (Bruker, USA), equipped with FluidFM technology (Cytosurge AG, Switzerland). Experiments were performed in PBS, using microfluidic micropipette probes with an aperture of 8 µm (spring constant of 0.3, and 2 N/m, Cytosurge AG, Switzerland).…”

“…For that, we probed the hydrophobic properties of the surface of living cells in the different conditions using a method recently developed in our team based on FluidFM [44], which combines AFM and microfluidics. It consists in producing a bubble at the aperture of a FluidFM cantilever, and probing its interactions with cells in force spectroscopy experiments [27]. As bubbles in water behave like hydrophobic surfaces, the interactions recorded directly reflect the hydrophobic properties of cells.…”

The contribution of Atomic Force Microscopy (AFM) in microalgae studies: A review

“…A pressure controller connected to these cantilevers then allow to exert a positive or negative pressure inside the cantilever. In different fields, such technology has already been used for example to probe the interactions of single cells aspirated at the aperture of cantilevers [52,53], to aspirate liquids from a cell 's interior for further analysis [54,55] or to create a microsized bubble to measure the hydrophobicity of single cells [56] . Such experiments applied to microalgae could help in analyzing the lipid profiles of different strains or in different conditions, which could bring valuable information to optimize culture conditions or microalgae strains.…”