A Novel Scanning Probe Microscopy technique to study the nanoscale electrical properties of cells
Martí Checa, Nanoscale bioelectrical characterization group
The goal of this work of thesis is the study of electrical properties in cells. That is the study of how they can conduct electricity, accumulate charges, or polarize. Experimental techniques able to measure electrical properties of complex heterogeneous samples (like cells) with excellent spatial resolution are needed to accomplish such characterization at the single-cell level (microscale) or even at the subcellular level (nanoscale). During this work of thesis, a new experimental technique named “Scanning Dielectric Force Volume Microscopy (SDFVM)” has been developed together with the theoretical modeling for its understanding when operated in a liquid environment.
The technique has been validated with known samples (both in dry and liquid) and applied to many different nanometric systems of interest. The first full map of the local dielectric constant of a prokaryotic cell in dry conditions has been obtained with unparalleled accuracy and spatial resolution, demonstrating its capability for label-free composition and structural mapping. Moreover, the method has been applied to liquid environment, obtaining the first-ever local dielectric contrast in fixed eukaryotic cells. Furthermore, the first preliminary results in living cells have also been shown. SDFVM is expected to have an important impact not only in Life Sciences but also in Material Science, where the mapping of the dielectric properties of samples showing complex nanoscale topographies is often needed.