No description available.

Ligand passivated nanoparticles have applications in solid-state lighting, plasmonics, and catalysis. At the nanoscale, the properties of these materials can be manipulated by reaction kinetics, allowing for systematic control to achieve desired functionalities and performance efficiency. Analysis of these properties and evaluating their fundamental behavior is challenging due to the complex chemistry at the nanoscale. Therefore, a combination of analytical techniques such as TEM, SEM, pXRD, NMR, and optical methods are required to study the structure and properties of these materials. This dissertation will consist of two topics covering nanoparticle synthesis and their applications. The first topic will discuss the use of 2 nm lanthanide doped nanospinels (Ln:ZnAl2O4, Ln = Tb, Eu) as down-shifting phosphors for solid-state lighting. Emission quantum yields up to 50% are achieved following energy transfer from a surface coordinating ligand. The second topic will discuss the synthesis and isolation of catalytic material from an iron-cobalt Prussian blue analogue (PBA). The isolated catalytic material retain elemental compositions and obey a scaling law with respect to the seed PBA, suggesting a templated interconversion. / A Dissertation submitted to the Department of Chemistry and Biochemistry in the partial fulfillment of the requirements for the degree of Doctor of Philosophy. / 2019 / October 17, 2019. / energy transfer, lanthanides, nanospinels, Prussian Blue Analogues, spinels / Includes bibliographical references. / Geoffrey F. Strouse, Professor Directing Dissertation; William S. Oates, University Representative; Albert E. Stiegman, Committee Member; Kenneth Hanson, Committee Member.

Nanotechnology is a new frontier for the advancement of science and technology. Nanomaterials are playing a crucial role and that they will continue to do so is beyond doubt. They are being used in electronic, magnetic, optical and catalytic applications where the unique interactions of nanostructured materials with electromagnetic radiation is of great benefit. While significant progress in understanding fundamental nanoparticle - electromagnetic radiation interactions has been made, and has improved practical technology applications, there is plenty left to be fully understood. This dissertation aims to further probe nanoparticle - electromagnetic radiation interactions and unveil details previously not known. More specifically, this dissertation looks at how microwaves can aid in the synthesis of anisotropic magnetic nickel nanoparticles, how small sized nanoparticles can be used in tuning the dielectric properties of polymer-nanocomposites, and how core-shell nanoparticles can be used for high quenching of fluorescence red dyes. An overview of chapters section that provides a more detailed content summary for each chapter is found at the end of the introduction chapter. / A Dissertation submitted to the Department of Chemistry and Biochemistry in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester 2018. / July 13, 2018. / anisotropic, microwave, nanoparticle, nickel, polymer nanocomposite, surface energy transfer / Includes bibliographical references. / Geoffrey F. Strouse, Professor Directing Dissertation; Subramanian Ramakrishnan, University Representative; Joseph B. Schlenoff, Committee Member; Lei Zhu, Committee Member.

Nanoparticle based cellular therapies hold great promise for clinical applications and medicinal use in human patients by allowing for targeted delivery of a personalized medicine payload to specific cells and tissues in a variety of disease states. The large surface to volume ratio of solid inorganic nanoparticles and the availability of facile surface functionalization chemistries with gold, gold-coated, and semi-conductor nanoparticles enables the design of delivery agents which can simultaneously carry a targeting molecule, such as an antibody or cell penetrating peptide (CPP), a short oligonucleotide for RNA interference or intracellular sensing, and a full gene for genetic therapy to correct aberrant protein function or cause apoptosis of cancer cells. The scope of applicability for nano-therapy technology is incalculable, however current understanding of the intracellular uptake and processing of nanomaterials-based therapeutics is limited and many facets of the cellular response to nanoparticle therapy are still in need of investigation. The goal of this dissertation work has been to elucidate the effects of nanoparticle-based therapeutics to ascertain the intracellular fate and processing of model nanomedicines by designing nanoparticle-bioconjugates capable of spatiotemporally reporting live intracellular uptake and processing events using fluorescence microscopy, and magnetic detection. The first chapter gives an introduction to nanoparticles and their use in biological applications, as well as detailing how they can be used as intracellular sensors. The second chapter investigates the ability to control therapeutic DNA cargo release from a gold nanoparticle in live cells using different appendage chemistries. The third chapter probes the intracellular environment experienced by the nanotherapeutic and discusses nano-induced effects to the intracellular environment. The fourth chapter investigates nanotherapy cellular uptake targeting using cell penetrating peptides, as probed by fluorescent quantum dots, to determine outcomes for a variety of naïve and drug resistant mammalian cell lines, include human lung, skin and brain cancers as well as rodent cancer model cell lines. The fifth chapter combines optical and magnetic analysis techniques to investigate multiplexed sensing with gold shelled iron oxide nanoparticles to investigate cellular uptake. And the last chapter summarizes the work and provides a discussion of the outlook for the work. / A Dissertation submitted to the Department of Chemistry and Biochemistry in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester 2018. / July 11, 2018. / cell penetrating peptide, DNA, gold nanoparticle, nano-probe, nano-therapeutic, surface energy transfer / Includes bibliographical references. / Geoffrey F. Strouse, Professor Directing Dissertation; Cathy W. Levenson, University Representative; Joseph Schlenoff, Committee Member; Wei Yang, Committee Member.

abstract: More recently there have been a tremendous advancement in theoretical studies showing remarkable properties that could be exploited from transition metal dichalcogenide (TMDC) Janus crystals through various applications. These Janus crystals are having a proven intrinsic electrical field due to breaking of out-of-plane inversion symmetry in a conventional TMDC when one of the chalcogenides atomic layer is being completely replaced by a layer of different chalcogen element. However, due to lack of accurate processing control at nanometer scales, key for creating a highly crystalline Janus structure has not yet been familiarized. Thus, experimental characterization and implication of these Janus crystals are still in a state of stagnation. This work presents a new advanced methodology that could prove to be highly efficient and effective for selective replacement of top layer atomic sites at room temperature conditions. This is specifically more focused on proving an easy repeatability for replacement of top atomic layer chalcogenide from a parent structure of already grown TMDC monolayer (via CVD) by a post plasma processing technique. Though this developed technique is not limited to only chalcogen atom replacement but can be extended to any type of surface functionalization requirements. Basic characterization has been performed on the Janus crystal of SeMoS and SeWS where, creation and characterization of SeWS has been done for the very first time, evidencing a repeatable nature of the developed methodology. / Dissertation/Thesis / Masters Thesis Materials Science and Engineering 2019

Quantum dots (QDs) are semiconductor nanoparticle fluorophores with size tunable emission wavelengths and large absorption cross sections, making QDs ideal optical imaging agents. Optical imaging has seen considerable academic and commercial interest, particularly for preclinical imaging. This interest stems from the capacity to multiplex, i.e., the detection of multiple independent imaging probes simultaneously, the accessibility of optical imaging equipment, and the absence of ionizing radiation. Since multiple in vivo targets can be imaged simultaneously, multiplexing is particularly appealing for targeted molecular imaging. In oncology, where a myriad of receptors can be used as targets for personalized medicine, multiplexed imaging would improve rapid receptor status profiling. Given their flexible design, QDs can be engineered for use as targeted contrast agents. To meet the needs of this application, the QDs must 1) emit in the near or short wavelength infrared (NIR/SWIR) wavelength regime to mitigate absorption of light by tissues, 2) be biocompatible, and 3) enable functionalization with targeting agents, such as antibodies or small molecules. In this thesis, the first requirement was addressed by synthesizing an inverted Type-I ZnSe/InP/ZnS system, which is the first InP based system with tunable emission past 750 nm. Biocompatibility of the InP system was confirmed with in vivo toxicity studies of the ZnSe/InP/ZnS QDs. The third requirement was addressed by the development of bioconjugation and functionalization schemes resulting in active QD targeting to the biologically interesting cellular targets human epidermal growth factor receptor 2 (HER2) and folic acid receptor alpha. In addition to developing the new contrast agent, the imaging approach was also refined to address concerns of non-specific labeling of the tumor. To discern between targeted and untargeted binding in vivo, a dual tracer approach using both an untargeted and targeted imaging probe, paired with a corresponding image processing algorithm, was implemented and validated. Identifying the limitations of this approach in NIR-I imaging, resulting from tissue auto fluorescence and light attenuation, laid the groundwork for future imaging work in the SWIR. In order to explore the utility of SWIR for dual tracer approaches, PbS/CdS QDs emitting throughout the SWIR wavelength regime were synthesized. The PbS/CdS QDs were used to generate pilot in vivo SWIR imaging data in collaboration with the National Research Council of Canada. The pilot data demonstrate that tissue attenuation and autofluorescence will not be an issue in the SWIR wavelength regime. By pairing SWIR emitting QDs with dual tracer imaging principles, future studies may be able to discern tumor biomarker status at tissue depth. Such an approach would allow researchers to determine how tumors respond to targeted therapies, furthering the development of personalized medicine. / 2022-09-27T00:00:00Z

No description available.

No description available.

No description available.

No description available.