The Nanofluidic Field-Effect in Electrically Actuated Nanopores

There exists a fluidic version of the electrostatic field-effect, by which the transport of ions, fluids, and charged objects in solution can be controlled in nanoscale channels. Here we present a theory of such ``electrofluidic'' gating, the fabrication of electrically articulated nanopore devices that can exploit it, and experiments that illustrate its potential. Our model accounts for surface chemistry, which plays a central role in real devices. Our fabrication methods, which are based on high-resolution milling techniques, can articulate nanopores with either a single annular gate electrode or two transverse CNT nanoelectrodes. Conductance gating experiments show a strong dependence on pH and ionic strength that is well described by our electrofluidic gating model. We seek to apply electrostatic control over the translocation of DNA through a gated nanopore, and thereby mimic the single-molecule regulatory capabilities of biological nanopores.