Thomas Auger

The study of macromolecular transport through nanopores has mainly been carried using electrical detection in a fashion similar to a Coulter-Counter technique. Here we propose to investigate the forced translocation of single DNA molecules though solid state nanopores by means of an optical detection. The forced penetration is achieved by applying a controlled pressure difference and the dyed DNA molecules are monitored when exiting/entering the membrane. This single molecule optical detection has allowed us to observe and quantify, for the first time with DNA polymers, the pressure threshold predicted by de Gennes and Brochard when forcing the penetration of polymers through nanopores via a solvent flow, as well as exploring their behavior when exiting/entering the membrane. We also investigated how the grafting of small neutral polymer chains on the membrane impact the threshold in the perspective of employing the setup we have developed towards the study of biological systems such as the nuclear pore complex.