Fig. 1
From: Nanopore extended field-effect transistor for selective single-molecule biosensing
Schematic of the nexFET biosensor. The nexFET platform is a functionalizable ionic nanopore transistor and is based on a dual-barrel quartz nanopipette with one barrel filled with a carbon nanoelectrode that also forms in a localized manner around the pipette tip. The ring-like carbon-electrode surrounding the nanopore is coated with PPy using ionic current feedback controlled electropolymerization, which serves to decrease the opening size of the second barrel. The PPy acts as a gate electrode surrounding the second barrel, a nanopore, that remains open and acts as a drain-source channel. By controlling the gate voltage molecular transport properties and event rates can be efficiently controlled at the single-molecule level. In addition, the PPy gate layer is ideally suited for embedding of artificial receptors that can be used for selective molecular sensing. Both strategies are explored for DNA detection and for protein sensing
