Figure 4.

Transport of 150 nM 100 bp double-stranded DNA (dsDNA) through a d = 3.6 nm HfO₂ nanopore. (a) Continuous two-second current trace at V = 100 mV. (b) Representative concatenated events following analysis using OpenNanopore⁵³ software. Each event is defined by its mean current amplitude (ΔI) and dwell time (t_d). Red line represents square wave fit to each event. (c) Histograms of ΔI at different voltages in the range V = 100–250 mV, showing a regular increase in ΔI with increasing voltage. Inset shows the fractional blockage, ΔI/I_o, which is found to be independent of voltage. (d) Distributions of event interarrival times at different voltages (δt). Lines are fits to the distributions, from which the capture rates R_c are extracted. (e) Scatter plots of ΔI vs t_d for selected voltages. The decrease in spread of t_d values with increasing voltages exemplifies the transition from diffusion-dominated to drift-dominated transport. (f) Peak t_d (left axis) and R_c (right axis) values as a function of voltage (see Supporting Information), showing exponential dependence for both parameters (see text).