Una nova tècnica de microscòpia de forces atòmiques per a l'estudi de les propietats nanoelèctriques de les cèl·lules

Abstract

[eng] This work of thesis is organized into 8 different chapters: Chapter 1: introduces the nanoscale electrical properties of cells and their relevance in the different fields of science in order to establish a framework for the objectives of the project. Chapter 2: introduces the Scanning Probe Microscopy techniques, with a special interest in its electrical modes. It mainly focuses the interest on Electrostatic Force Microscopy as it is the technique used during the project. Motivation and objectives of the thesis: Once the introductory chapters have established a framework for the realization of the thesis, its motivation, and its main goals are exposed. Chapter 3: covers the theoretical modeling of electrostatic force measurements in electrolyte solutions for 1D geometry. Chapter 4: extends the theoretical modeling of electrostatic force measurements in electrolyte solutions to 3D realistic geometries, and their implications regarding EFM in liquid media are discussed. Chapter 5: presents and validates a new SPM technique called Scanning Dielectric Force Volume Microscopy (SDFVM) designed specially to deal with topographically complex and heterogeneous samples like cells. Chapter 6: exposes the application of SDFVM to obtain the first (to our knowledge) local dielectric constant map of a cell at the sub-cellular level. Chapter 7: uses the developed technique to obtain EFM images of different interesting systems in nanotechnology, showing the power of method by achieving nice images in a wide range of systems going from small nanowires to big eukaryotic cells. Chapter 8: presents the steps performedtowards implementing SDFVM into liquid environments, and some preliminary results for fixed and living eukaryotic cells in pyhsiological conditions. Then the conditions of the project and its futures perspectives are exposed. The references can be found at the end of the document.