Towards Hybridization-Assisted Nanopore DNA Sequencing

Hybridization-Assisted Nanopore DNA Sequencing method has been proposed to overcome two of the current difficulties in nanopore DNA sequencing: fabricating a nanopore with length comparable to the length of a single base and detecting the characteristic transient current blockages of single DNA bases.;We demonstrated fabrication of solid state nanopores in silicon chips by feedback chemical etching method and the functionality of these nanopores by measuring DNA translocation events.;We performed the first reverse DNA translocation experiment using magnetic tweezers. Controlled capture and release of DNA from a solid-state nanopore have been demonstrated. Comparing to the optical tweezers approach, the scalability of magnetic tweezers approach has its unique advantage, as it is only limited by the size of nanopore array chip one can make. Unlike that in the optical tweezers approach, the ionic current through the nanopore is not coupled with the motion of the bead for the magnetic tweezers approach. In addition, by using permanent magnets, the magnetic tweezers are of lower cost and more compact than the optical tweezers. Although this magnetic tweezers approach can not control precisely the position of the DNA as the optical tweezers approach does, the average speed of the reverse DNA translocation by magnetic tweezers is demonstrated to be 2000-fold slower than that of the standard DNA translocation, applicable for most nanopore DNA characterizations, including the Hybridization-Assisted Nanopore DNA Sequencing proposal.