Biological nanopores are uncanny molecular machines that perform a wide variety of cellular functions, from sorting biomolecules to building cellular osmotic pressure and folding newly synthesised proteins. Their performance, as measured, for instance, by their energy efficiency, is unmatched by any other artificial system. Some biological nanopores as the nuclear pore complex induce the directionnal transport of macromolecules such as DNA, RNA and proteins. In this internship/PhD project, our aim is to investigate directional transport using to two distincts scenario : - Translocation ratchet : A molecular agent present downstream bind to the transported molecule and exert an effective translocation force on the species present upstream. - Translocation induced by the enhanced mobility of enzymes in presence of their substrate. The transport of single macromolecules will be measured by a near-field optical technique developed in the laboratory (Zero-Mode Waveguide for nanopores). Using a unique in France optical tweezers system coupled to a confocal microscope and a microfluidic system (Lumicks C-Trap) the forces involved in the transport will also be measured. From this measurement, we will extract the change in the translocation energy landscape in the presence of ratchet agents.