A novel scanning probe microscopy technique to study the nanoscale electrical properties of cells
- Autores: Martí Checa Nualart
- Directores de la Tesis: Gabriel Gomila Lluch (dir. tes.)
- Lectura: En la Universitat de Barcelona ( España ) en 2020
- Idioma: español
- Tribunal Calificador de la Tesis: Daniel Navajas Navarro (presid.), Laura Fumagalli (secret.), Juan José Sáenz Gutiérrez (voc.)
- Programa de doctorado: Programa de Doctorado en Nanociencias por la Universidad de Barcelona
- Materias:
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- Resumen
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. To accomplish such characterization at the single cell level (microscale) or even at the subcellular level (nanoscale), experimental techniques able to measure electrical properties with great resolution are needed.
Electrostatic force microscopy (EFM) has emerged recently as an appealing candidate for it, due to its excellent spatial resolution and its ability to measure simultaneously the topography and the electrical properties of the sample of interest (both in dry and liquid environments).
During this work of thesis, a new experimental technique named as “Scanning Dielectric Force Volume Microscopy (SDFVM)” has been developed. It is specially adapted to measure topographically complex and electrically heterogeneous samples like cells. The technique has been validated with known samples (both in dry and liquid) and applied to different nanometric systems of interest. It has shown its excellent capability of obtaining subsurface information and generating local dielectric constant maps with an unparalleled accuracy and spatial resolution.
The main results obtained during the project are:
- The first map of local dielectric constant of a prokaryotic cell, demonstrating the capability of SDFVM for label-free composition and structural mapping. (Published in 2019 in Nanoscale).
- The first full theoretical model (including diffusion of chemical species) of the forces acting on the tip in EFM in liquid. Which are needed to understand its frequency, concentration and distance dependence both in 1D geometries (Published in 2019 in Physical Review E) and 3D geometries (Article in preparation).
- Obtaining the first ever local dielectric contrast in fixed eukaryotic cells and the first preliminary results of EFM measures in living cells. (Article in preparation).
- The nanoscale characterization of a fully functional device like an Electrolyte Gated Organic Field Effect Transistor (EGOFET) and its correlation to its macroscopic properties, which shows the wideness of applicability of SDFVM as well in Material Science.
Because this thesis runs over the development of both a new experimental technique and new theoretical models for its qualitative understanding and its quantification, it pretends to have a great impact not only in Life Sciences but also in Material Science, where the characterization of nanoelectrical properties is as well of great interest.
