engleski

Diatom Nanomechanics

Nanostructural and nanomechanical characterization of diatom cells and extracellular polymers is crucial for understanding of their function at the cellular level, and makes a basis for further research in marine ecology. Here, the potential of AFM to study diatom cell walls and extracellular polymers (EPS) will be presented. Atomic Force Microscopy (AFM) connects the nanometer and micrometer length scales utilizing a sharp probe tip that senses interatomic forces acting between the surface of a sample and the atoms at the apex of the tip. The physical basis behind AFM and its ability to „”feel“ the surface, make AFM a new tool in diatom characterization. AFM studies already played a significant role in advancing our understanding of diatom biomineralization and morphogenesis and its unique ability to measure forces enabled discoveries on mechanical properties and function of diatom EPS. Here, we will present recent achievements of AFM application to diatom nanomechanics, on weakly silicified marine diatom Cylindrotheca closterium (CCNA1) isolated from Northern Adriatic. The nanomechanical properties (elasticity, deformation) of live diatom were measured in seawater over the entire cell surface using novel Peak Force Tapping mode for the first time and SiO2 nanoparticles were discovered in the valve region. The single molecule force spectroscopy was applied to probe the mechanical response of C. closterium EPS biopolymers and the networks they form. Combining force measurements and high resolution AFM imaging allowed us to identify the microscopic origins of distinct mechanical responses.

diatom; AFM; nanomechanics

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