Fig. 1: Experimental set-up and characterization of quartz nanopores.
From: On the origins of conductive pulse sensing inside a nanopore
a TEM of quartz nanopore; scale bar, 50 nm. b I–V curves pertaining to four differently sized nanopipette orifices. For pore size estimations, the linear portion at the negative voltages was used (yellow shaded region). The schematic within the I–V curves shows the directionality of EOF and EPF at negative voltages. c EOF, EPF drift, and the resulting net velocities of λ-DNA along the pore’s axis of symmetry (μ = 3.2 × 104 cm/Vs). Distance from the pore is radial from the axis of symmetry. d Simulations of fluid flow velocities under low ionic strength conditions. White lines indicate fluid flow lines for a 20 nm pore at −600 mV voltage bias. Inset: YOYO-labeled DNA sample with an applied voltage of −700 mV to visualize the capture zone. e Event frequency with depth of the pipette inside the bath solution. Nanopore depth is synonymous with how deep the nanopore tip was submerged into the analyte-containing bath solution. Error bars show the standard deviation of each condition. f Linear DNA events from 17 pores were investigated for pore size dependence on current amplitude. We see that the enhancements fluctuate between 60 and 140 pA with no discernable trend. Errors bars represent the standard deviation of the current change.
