Versatile ultrathin nanoporous silicon nitride membranes

摘要: Single- and multiple-nanopore membranes are both highly interesting for biosensing separation processes, as well their ability to mimic biological membranes. The density of pores, shape, surface chemistry the key factors that determine membrane transport capabilities. Here, we report silicon nitride (SiN) with fully controlled porosity, pore geometry, chemistry. An ultrathin freestanding SiN platform is described conical or double-conical nanopores diameters small several nanometers, prepared by track-etching technique. This technique allows porosity be tuned from one billions pores per square centimeter. We demonstrate capabilities these discrimination dye protein molecules based on charge size. process an electrostatic mechanism operates in physiological electrolyte conditions. As have also shown, can chemically modifying walls. Compared typical cylindrical reported here allow higher fluxes, a critical advantage applications. In addition, shape results shorter effective length, which gives advantages single biomolecule detection applications such nanopore-based DNA analysis.