Fig. 1: Single-nanoparticle detections using a surround gate nanopore.
From: Field effect control of translocation dynamics in surround-gate nanopores
a A schematic model depicting electrophoretic translocation of a 200 nm-sized carboxylated polystyrene nanobead through a 300 nm diameter surround-gate nanopore under the applied cross-membrane Vb and gate voltage VG. Optical images of the nanopore chip showing an overview (b) and a magnified view at the center (c). The gate voltage was added to the Pt surround gate via the microelectrodes. Entire surface except the 50 μm region around the nanopore was coated with a thick polyimide layer for lowering capacitance-induced high-frequency noise of the cross-membrane ionic current Iion. d A scanning electron micrograph of the 300 nm-sized gating nanopore. e Iion versus Vb characteristics in 1 × PBS under different VG conditions. A partial Iion versus time (t) trace (f) and a close view of a resistive pulse (g) occurred upon a nanoparticle passed through the nanopore. The width of the signal td represents the time required for the particle to move through the channel. The base current is offset to zero.
