Enhanced Pulley Effect for Translocation: The Interplay of Electrostatic and Hydrodynamic Forces

Solid-state nanopore sensors remain a promising solutionto therising global demand for genome sequencing. These single-moleculesensing technologies require single-file translocation for high resolutionand accurate detection. In a previous publication, we discovered ahairpin unraveling mechanism, namely, the pulley effect, in a pressure-driventranslocation system. In this paper, we further investigate the pulleyeffect in the presence of pressure-driven fluid flow and an opposingforce provided by an electrostatic field as an approach to increasesingle-file capture probability. A hydrodynamic flow is used to movethe polymer forward, and two oppositely charged electrostatic squareloops are used to create an opposing force. By optimizing the balancebetween forces, we show that the single-file capture can be amplifiedfrom about 50% to almost 95%. The force location, force strength,and flow rate are used as the optimizing variables.