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Second Harmonic Generation Spectroscopy And Microscopy Of Liposomes, Nanoparticles, And Cells, Prakash Hamal
Second Harmonic Generation Spectroscopy And Microscopy Of Liposomes, Nanoparticles, And Cells, Prakash Hamal
LSU Doctoral Dissertations
Second harmonic generation (SHG) is used to investigate the factors that impact nanoparticle-based drug-delivery applications. In the first study, molecular adsorption and transport kinetics of a positively-charged dye, malachite green isothiocyanate (MGITC), is characterized at the surface of different colloidal liposomes in water using SHG spectroscopy. The molecular interactions of MGITC is compared to our previous investigations with malachite green (MG). In comparison to MG, MGITC demonstrates stronger adsorption and faster transport through lipid membranes. Correspondingly, the SHG experimental results are in excellent agreement with the molecular dynamics (MD) simulations results. A key finding illustrates the importance of functional groups, …
Electrification Ionization: Fundamentals And Applications, Bijay Kumar Banstola
Electrification Ionization: Fundamentals And Applications, Bijay Kumar Banstola
LSU Doctoral Dissertations
Electrification ionization is a method to produce ions from solid samples by charge separation. This separation of charge can be enhanced by organic molecules known as matrix compounds to produce highly charged molecules. In this research, new methods were developed for the application of electrification ionization for surface analysis and the ionization mechanism was investigated. First, an electrification ionization matrix was used for tissue imaging using laser ablation. A two-component matrix of 2-nitrophloroglucinol and silica nanoparticles was found to increase the number of multiply charged ions from the tissue. Images of mouse brain with multiply charged ions were obtained. In …
Ultrafast And Nonlinear Spectroscopy Of Nanomaterials, Rami Anthony Khoury
Ultrafast And Nonlinear Spectroscopy Of Nanomaterials, Rami Anthony Khoury
LSU Doctoral Dissertations
Ultrafast and nonlinear spectroscopies are implemented in the investigation of excited-state dynamics and structural properties of materials and nanomaterials. In the first study, the excited-state dynamics of size-dependent colloidal TiO2-Au nanocomposites are investigated using ultrafast transient absorption spectroscopy. The dynamics corresponding to the plasmon depletion band are characterized by electron-phonon and phonon-phonon coupling lifetimes that are observed to be independent of the gold nanocluster shell thickness. The excited-state dynamics corresponding to the interband transition of gold is also spectrally overlapped with the interfacial electron transfer lifetime, which is shown to decrease as the nanocluster shell thickness increases. In …
Chemotherapeutic Applications Of Rhodamine Based Nanogumbos, Nimisha Bhattarai
Chemotherapeutic Applications Of Rhodamine Based Nanogumbos, Nimisha Bhattarai
LSU Doctoral Dissertations
The work presented in this dissertation employs nanomaterials derived from a group of uniform materials based on organic salts (GUMBOS) for selective chemotherapeutic applications. GUMBOS, similar to ionic liquids, are organic salts consisting of a bulky cationic and anionic moiety. In contrast to ionic liquids, these materials have melting points ranging from 25–250 °C, making them solid phase at room temperature. Similar to ionic liquids, GUMBOS display tunable properties, such as hydrophobicity and solubility, through counter ion variation. These tunable properties provide a variety of applications for these GUMBOS, including selective chemotherapeutics applications. The …
Nanopatterns Of Zinc Phthalocyanines, Gold Nanoparticles, And Porphyrins Prepared Using Particle Lithography: Characterization Of Patterning Steps With Scanning Probe Microscopy, Ashley Marie Taylor
Nanopatterns Of Zinc Phthalocyanines, Gold Nanoparticles, And Porphyrins Prepared Using Particle Lithography: Characterization Of Patterning Steps With Scanning Probe Microscopy, Ashley Marie Taylor
LSU Doctoral Dissertations
The growth and self-assembly of molecules on surfaces can be directly visualized at the molecular level using studies which combine nanoscale lithography and high-resolution imaging. Nanopatterning provides a unique and practical approach for direct views of surface changes after the key chemical steps of nanopatterning, providing landmarks and baselines for measuring growth in vertical and lateral dimensions. Controlling the arrangement of materials on surfaces at the nanoscale can be achieved using particle lithography. Arrays of well-defined nanostructures can be prepared with reproducible geometries and arrangement. Results for the preparation of nanopatterns produced with particle lithography are presented using high resolution …
Coupled Plasmon/Molecule Dynamics Near Core-Shell Nanoparticles: Synthesis, Ultrafast Characterization, And Quantum/Classical Modeling, Holden Tyler Smith
Coupled Plasmon/Molecule Dynamics Near Core-Shell Nanoparticles: Synthesis, Ultrafast Characterization, And Quantum/Classical Modeling, Holden Tyler Smith
LSU Doctoral Dissertations
In this dissertation, the resonance coupling of chromaphoric dyes adsorbed on the surface of plasmonic nanoparticles (NPs) are investigated using a combined theoretical and experi- mental approach. Colloidal gold, gold-silver core-shell, silver-gold core-shell, and gold-silver- gold core-shell-shell NPs are considered. These NPs are thiolated with mercaptosuccinic acid, and malachite green dyes are adsorbed to the surface of the nanoparticle (NP) via elec- trostatic interactions. Second harmonic generation is used to determine the surface to the isotherm of the molecular dyes to the colloidal nanoparticle surface. Adsorption isotherms show that the SHG intensity increases as the concentration of dye increases, reaching …
Studies Of The Properties Of Designed Nanoparticles Using Atomic Force Microscopy, Steve Matthew Deese
Studies Of The Properties Of Designed Nanoparticles Using Atomic Force Microscopy, Steve Matthew Deese
LSU Doctoral Dissertations
The purpose of the research in this dissertation was to elucidate the intrinsic properties of how nanoparticles are different from bulk materials. This was done by mechanical and electronic studies of the properties of designed nanoparticles using advanced modes of atomic force microscopy. Information relating to the work functions, contact potential difference, Young’s Moduli, elasticity, and viscoelasticity can be investigated using state-of-the-art atomic force microscope (AFM) experiments. Subsurface imaging of polystyrene encapsulated cobalt nanoparticles was achieved for the first time using Force Modulation Microscopy (FMM) in conjunction with contact mode AFM. Previously prepared sample of polystyrene coated cobalt nanoparticles were …
Nanoscale Gumbos: Size-Control, Characterization, And Applications As Enantioselective Molecularly Imprinted Polymers And Fluorescent Materials, Suzana Hamdan
LSU Doctoral Dissertations
Nanomaterials derived from a group of uniform materials based on organic salts (GUMBOS) have been introduced into the scientific literature through many analytical, biological, and technological applications. These nanomaterials, referred to as nanoGUMBOS, have been shown to display a number of interesting properties including fluorescence, magnetism, tumor targeting, and optoelectronic properties. Herein, we present major studies on nanoGUMBOS including synthesis and size-control, chiral molecular imprinting in polymers, as well as investigation of optical properties and quantum yield of fluorescent semiconductor-based nanoGUMBOS. Various strategies were introduced for production of well-defined nanoGUMBOS. Specifically, several methods based on sonochemistry, microwave, cyclodextrin, and surfactant-assisted …
Scanning Probe Investigations Of Magnetic Nanoparticles, Protein Binding And The Synthesis Of Rare Earth Oxide Nanoparticles Using Nanoscale Lithography, Lauren Elizabeth Englade-Franklin
Scanning Probe Investigations Of Magnetic Nanoparticles, Protein Binding And The Synthesis Of Rare Earth Oxide Nanoparticles Using Nanoscale Lithography, Lauren Elizabeth Englade-Franklin
LSU Doctoral Dissertations
Approaches to prepare spatially selective surfaces were developed in this dissertation for constructing assemblies of biomolecules and inorganic materials. Nanoscale surface patterns of organic thin films were prepared using particle lithography combined with organosilane chemistry. Biological and inorganic nanomaterials can be patterned with tailorable periodicities, which can be controlled by selecting the diameter of mesospheres used as surface masks. The surface platforms of well-defined nanopatterns are ideal for high resolution investigations using scanning probe microscopy (SPM). Local measurements of surface properties combined with visualization of the steps of chemical reactions at the molecular level were accomplished. Fundamental studies of the …
Synthetic Routes To Therapeutic Agents Via Masked Functionalities: From Orthogonal Peptide Crosslink To Photothermal Cancer Prodrug, Chyree Shantel Batton
Synthetic Routes To Therapeutic Agents Via Masked Functionalities: From Orthogonal Peptide Crosslink To Photothermal Cancer Prodrug, Chyree Shantel Batton
LSU Doctoral Dissertations
The theonellamides are a family of compounds distinguished by their crosslinking ô-histidinoalanine (ô-HAL) residue. Part one of this dissertation details the synthesis of an orthogonally protected ô-HAL building block that will be incorporated into a total synthesis of theonellamide C. Selective deprotection of each amine and acid of this orthogonally protected building block is also demonstrated. Various reaction partners for the assembly of ô-histidinoalanine were explored. One approach involved the coupling of N-Fmoc-â-iodoalanine benzyl ester and (Nðim)-blocked histidine nucleophiles including a fused bicyclic urea and a Boc-His(Nð-Pac)-OMe. While the imidazolium salts were identified by mass spectrometry, elimination of the iodide …
Luminescence Studies : Part I. Lanthanide Nanogumbos Part Ii. Near Infrared Photothermal Nanogumbos, Jonathan Carver Dumke
Luminescence Studies : Part I. Lanthanide Nanogumbos Part Ii. Near Infrared Photothermal Nanogumbos, Jonathan Carver Dumke
LSU Doctoral Dissertations
Group of Uniform Materials Based on Organic Salts (GUMBOS) are a class of molten salts that have been focused to be specifically tailored towards applications. Primitively, from Davy to Walden molten salts were desirable for organic synthesis due to the properties. GUMBOS have been synthesized into nanoparticles (nanoGUMBOS) by various methods to be used for lanthanide luminescence and hyperthermal cancer therapeutics. Lanthanide photochemistry has been frequently studied for its high luminescence intensity, narrow emission band, and stable luminescent lifetime decay. Aerosol-derived europium nanoGUMBOS were characterized using electron microscopy (39.5 ± 8.4 nm), XPS, and spectroscopic techniques. Spectroscopic measurements indicated intense …
Analysis Of Protein Aggregates And Synthetic Nanoparticles Using Capillary Electrophoresis With Light Scattering And Fluorescence Detection, Suresh Chandra Regmi
Analysis Of Protein Aggregates And Synthetic Nanoparticles Using Capillary Electrophoresis With Light Scattering And Fluorescence Detection, Suresh Chandra Regmi
LSU Doctoral Dissertations
The goal of the research presented in this dissertation is to develop capillary electrophoresis (CE) based analysis techniques for the characterization of individual particles including amyloid beta (Aâ) peptide aggregates and to apply these methods to study the aggregation of Aâ peptides. Protein self-assembly into ordered aggregates is a common and important process in normal biological function, but this process is also involved in several diseases. Amyloid beta peptide aggregation is linked to Alzheimer’s disease. Thioflavin T (ThT) has been used as a fluorescent probe for the detection of Aâ aggregation. Based on previous observations of false positive fluorescent signals …
Investigations Into The Role Of Natural Organic Matter As An Interface Between Aquatic Organisms And Environmental Pollutants, Caroline Lillian Schneider
Investigations Into The Role Of Natural Organic Matter As An Interface Between Aquatic Organisms And Environmental Pollutants, Caroline Lillian Schneider
LSU Doctoral Dissertations
The impact of the continuous pollution of freshwater environments by multiple pollutants has not been well-studied. The goal of this research was to evaluate the toxicity of several modern pollutants in a model environment. The prokaryotic, unicellular blue-green algae Synechocystis WT6803 and the eukaryotic, multicellular Utterbackia imbecillis mussel larvae were studied along with Suwannee River natural organic matter (NOM). The toxicity response of the blue-green algae Synechocystis sp. was measured through changes in growth rates. The inorganic pollutant silver nanoparticles (0.044 μM) were toxic. Gold nanoparticles did not affect the growth rate. The addition of 15 mg/L NOM partially inhibited …
Investigations Into The Role Of Humic Acid In Biomembrane Permeability And The Effects Of Naturally Formed Gold And Silver Nanoparticles On These Interactions, Loice Marklyne Ojwang
Investigations Into The Role Of Humic Acid In Biomembrane Permeability And The Effects Of Naturally Formed Gold And Silver Nanoparticles On These Interactions, Loice Marklyne Ojwang
LSU Doctoral Dissertations
The mechanism and kinetics of the interaction of humic acids (HAs) with a 1-palmitoyl-2-oleoyl-Sn-glycero-3-phosphatidylcholine (POPC) large unilamellar vesicle (LUV) model biomembrane system were studied by fluorescence spectroscopy. All three HAs studied induced a perturbation to the biomembrane bilayer structure at pH 4.8. Concentration dependence studies revealed that biomembrane perturbation increased with increasing HA concentrations for Suwannee River HA (SWHA) from 0 to 20 mg C/L. For both Leonardite HA (LAHA) and Florida Peat HA (FPHA) aggregation influenced biomembrane perturbation at concentrations above 5 and 7.5 mg C/L, respectively. Temperature studies over the environmentally relevant ranges of 10 to 30 °C …
Geometrical And Electronic Structure Of Metal Oxide Nanoparticles On Silica And Alumina, Udaya Indike Rodrigo
Geometrical And Electronic Structure Of Metal Oxide Nanoparticles On Silica And Alumina, Udaya Indike Rodrigo
LSU Doctoral Dissertations
Recent studies demonstrated nanometer-scale combustion-generated nanoparticles cause demonstrable health effects. It is essential to understand the chemical characteristics of these nanoparticles. Since combustion-generated nanoparticles arise in complex mixtures, we employed a dendrimeric method to generate simpler, more reproducible nanoparticles, which were tethered to fumed silica and alumina to provide surrogates for fly ash. We collected XANES and EXAFS data, which are useful for characterizing disordered mixtures where the metal is a minor component. The effect of particle size on structural properties was studied with copper oxide nanoparticles on fumed silica. XANES data demonstrated copper atoms in the nanoparticles are present …
Task Specific Ionic Liquids For Enantiomeric Recognition And Nanomaterials For Biomedical Imaging, David Kipkogei Bwambok
Task Specific Ionic Liquids For Enantiomeric Recognition And Nanomaterials For Biomedical Imaging, David Kipkogei Bwambok
LSU Doctoral Dissertations
Ionic liquids (ILs) are organic salts that melt at or below 100°C. Interest in ILs continues to grow due to their unique properties such as lack of measurable vapor pressure, high thermal stability, tunability and recyclability. The first part of this dissertation explores the use of chiral ionic liquids (CILs) for enantiomeric recognition of chiral analytes using fluorescence spectroscopy. Chiral analyses continue to be a subject of considerable interest primarily as a result of legislation introduced by the Food and Drug Administration. This has led to an increased need for suitable chiral selectors and methods to verify the enantiomeric forms …