Nanopore tweezers: Voltage-controlled trapping and releasing of analytes

Several devices for single-molecule detection and analysis employ biological and artificial nanopores as core elements. The performance of such devises strongly depends on the amount of time the analytes spend into the pore. This residence time needs to be long enough to allow the recording of a high signal-to-noise ratio analyte-induced blockade. We propose a simple approach, dubbed nanopore tweezing, for enhancing the trapping time of molecules inside the pore via a proper tuning of the applied voltage. This method requires the creation of a strong dipole that can be generated by adding a positive and a negative tail at the two ends of the molecules to be analyzed. Capture rate is shown to increase with the applied voltage while escape rate decreases. In this paper we rationalize the essential ingredients needed to control the residence time and provide a proof of principle based on atomistic simulations.