CONTROLLING TRANSLOCATING MOLECULES THROUGH A NANOPORE
- University of Ottawa
- UNIVERSITY OF ROCHESTER MEDICAL CENTRE
To reduce unwanted variation in the speed of DNA translocating solid-state nanopores, a nanoscale pre-confinement of translocating molecules is demonstrated using an ultra-thin nanoporous silicon nitride (NPN) membrane separated from a single sensing nanopore by a nanoscale cavity. Comprehensive experimental results demonstrate that the presence of this nanofilter results in a global minimum in the coefficient of variation of passage times in the sensing pore over a range of DNA sizes which depends on the height of the cavity. Such advanced nanopore devices minimize the standard deviation of the passage time distribution independently of its diameter and stability. These results also represents the first experimental verification that the inter-and intra-molecular passage time variation depends on the conformational entropy of such molecule prior to translocation, while providing a practical strategy for controlling transport across solid-state nanopores.