This dissertation examines the effects of phase transfers with thiol ligands on the optical properties of quantum dots (QDs) in water by investigating two systems: i) dihydrolipoic acid (DHLA)-capped PbS QDs and ii) thiolated DNA-capped core/shell CdSe/CdS QDs. QDs are bright, monodisperse, and tunable hydrophobic nanoparticles with high photoluminescence (PL)...
Multimetallic nanoparticles represent an important class of electrocatalysts which are critical for many energy and environmental applications including fuel cells, hydrogen production, and greenhouse gas elimination. The properties of these nanoparticles depend on their composition, size, shape, and structure. Therefore, developing new strategies which provide a high level of control...
As demonstrated by efforts in graphene commercialization, scalable synthesis and high-quality material availability are primary limiting factors for the realization of technologies based on two-dimensional (2D) materials. Thus, in considering the fate of emergent 2D materials such as the metal chalcogenides, the challenge of scalable synthesis is a highly relevant...
Light trapping with standing waves has been achieved using photonic bandgap crystals, metal-dielectric waveguides and periodic metal nanocavity arrays. Compared with photonic materials, plasmonic metal nanocavities can provide light confinement at the sub-wavelength scale with strong near-field electric enhancement. The localized surface plasmons of individual metal nanoparticles can collectively couple...
Carbon nanotubes (CNTs) have exceptional properties and are mass-producible at the ton scale as aggregated powders, but their difficulty in processing is a significant barrier to widespread use. Even after decades of research, there still isn’t a solvent for CNTs that is massively available, easily removable, and non-damaging. The need...
Nucleic acid drugs promise to revolutionize the development of therapeutics. They offer a platform for digital medicine, where systematic changes to the nucleic acid sequence can be utilized to target the entire human genome. However, nucleic acids suffer from a number of drawbacks, such as negligible cellular uptake and rapid...
This dissertation describes modifications to the surface of colloidal semiconductor quantum dots (QDs) to improve their use as photocatalysts for charge transfer reactions. The surface atoms and ligands of these nanoparticles can interfere with direct charge transfer to a reagent by inhibiting binding, forming trap states, or acting as competitive...
Semiconductor nanowires, such as group IV and III-V nanowires, shows distinct electrical, optical and mechanical properties from their bulk counterparts due to their nanoscale size and 1-D morphology. For example, the quantum confinement effect modulates the band gap of a semiconductor nanowire when its diameter approaches or below the exciton...
Connecting structure and function in nanoscale engineered materials and devices relies on the analysis of the fundamental arrangement of matter, frequently under dynamic conditions. The demand to image structures at fundamental length scales has touched inorganic materials, biology, and frequently hybrid hard/soft materials with unique phenomena driven by heterogeneous components....
Surface-enhanced Raman spectroscopy (SERS) is a powerful analytical technique that can detect single molecules and simultaneously obtain structural information. When an analyte molecule binds to a nanostructured noble metal surface, the otherwise weak normal Raman signal is enhanced by as much as a factor of 108. This makes SERS the...