Designing abiotic single nanotube membranes for bioanalytical and biomedical applications

The goal of this research is to develop abiotic nanostructured sensor platforms for bioanalytical and biomedical applications. The first part of this work is the fabrication of synthetic single nanopore membranes within a polymeric support. We describe here an alternative approach that we believe is easier and more accessible than previously described methods. Fluorescence microscopy is used to identify and isolate single nanopores within these membranes. Furthermore, an electroless plating method can be used to deposit a gold nanotube within the single nanopore, and this provides a route for further decreasing the inside diameter of the pore.; The second part relies on a method which allows one to prepare single asymmetric nanopores with a tailored cone opening angle, therefore controlling the effective length of the pores. This nanopore system is based on one sided chemical etching of heavy ion irradiated dielectric films. This process offers the advantage of controlling not only the pore diameter but the pore geometry as well. By controlling the pore dimensions it offers one the ability to fine tune the nanopore system for the analysis of individual molecules.; The third part of this work describes a device which consisted of a single conically shaped gold nanotube embedded within a polymeric membrane. This device mimics one of the key functions of biological voltage-gated ion channels---the ability to strongly rectify the ionic current flowing through it. We report here artificial ion channels that rectify the ion current flowing through them via an "electromechanical" mechanism. The electromechanical response is provided by single-stranded DNA molecules attached to the nanotube walls.; The final part of this work describes a nanodevice, which consisted of a single abiotic nanopore system. This system is used to analyze single DNA molecules based on the electrophoretic transport of the molecule through the single nanopore system. Finally, this system was used to discriminate between two different types of DNA molecules within a solution mixture. These nanopores show great promise for further biomolecular sensing applications due to there inert and mechanically robust characteristics.