Flow Injection of DNA in Nanopores : Direct Optical Visualization of a Pressure Threshold
Résumé
In the regime of pores smaller than the radius of gyration, the flow injection of polymers and biopolymers exhibit a flow threshold independent of the pore and of the polymer itself. We have developed a new combination of near field optics (zero mode wave guide) and image analysis in order to revisit this phenomenon. Working at constant pressure we are able to control and observe directly the transport of individual biomolecules with a time resolution of 5 ms. In the case of DNA, we show that the forced transport through the pore can be described as an energetic barrier only dependent on the injected flow. Further application to biological systems of this barrier measurement will also be discussed.