Abstract
Biological membranes are flexibles barriers that ensure cell permeability, delineating the cell boundaries and the intracellular compartments to organelles within the cell. They are composed mainly by phospholipids and proteins. Those components are the main ones responsible for membrane remodeling. The latter process is highly dynamic and requires observation at high spatial and temporal resolution. This thesis work focused on two main challenges in the study of membranes: i) Softness of biological membranes and their mechanical properties. Membranes are very soft and fragile materials, and determine their real morphology is highly complicated due to their softness. We have studied the maximal force exerted by an AFM tip that supported lipid bilayers can withstand before rupture, as well as their Young’s modulus, both as a function of the tip size. ii) Chemical sensitivity and molecular recognition in microscopy. AFM can achieve the topography of the membrane. However, this technique cannot distinguish the molecule below the AFM tip. In order to overcome this barrier, we worked on developing a new fluorescence super-resolution technique combining AFM and confocal microscopies. First, we developed a correlated and synchronous confocal Fluorescence-lifetime imaging microscope (FLIM)-AFM setup. Finally, we developed a Metal Induced Energy Transfer (MIET)-AFM setup in order to measure molecular recognition, topography, and mechanical properties of biological samples simultaneously.