Measuring Dna Translocation Forces Through Mos2-Nanopores With Optical Tweezers

Measuring the minute forces acting on a single charged polymer, like DNA, during the translocation through a nanopore offers valuable insights into translocation mechanics and dynamics. For increased sensitivity, both ultra-thin nanomembranes and small nanometer-sized nanopore diameters are desirable. In this paper, we show the preparation of free-standing monolayer molybdenum disulfide nanomembranes by exfoliation by both wet and dry transfer. We milled nanopores with approximately 40 nm diameter into those nanomembranes with a helium ion microscope. Finally, we measured the controlled DNA translocation through such a nanopore with optical tweezers and determined a translocation force of 7 pN at a transmembrane voltage of 50 mV. (C) 2017 The Authors. Published by Elsevier Ltd.