Molecular-Level Design of Nanoscale Environments for Enhanced Single-Molecule Sensing

Single molecule studies depend upon precise control over the chemical and physical structure of the nanoscale sensing instrumentation and environment, and this demand is particularly stringent in the case of nanopores, a unique tool for single-molecule sensing and manipulation. The size and shape of the nanopores are critical to their function, and each facet, alone, presents experimental hurdles; this dissertation contains an approach to address both, simultaneously. A method for electroless deposition of gold onto solid-state silicon nitride nanopores has been developed to provide a foundation for precision tailoring of surface properties and nanopore size to study single analyte molecules and their interactions with other molecules of interest. This study was designed to develop a set of tools to directly modify the surface of silicon nitride, and through this approach, to customize the nanopore size and surface properties for various molecular systems under investigation. The techniques discussed in this dissertation were successfully used to electrolessly deposit gold into silicon nitride pores, to create customized nanopores. These nanopores were characterized via a non-imaging, conductance-based, technique developed in this research group, and subsequently used to study the translocation of DNA molecules through the pores.