Physical Sciences and Mathematics Commons^™

Expanding The Scope Of Clickable Azide-Functionalized Nanoclusters To Include Au144, Johanna A. De Jong

Electronic Thesis and Dissertation Repository

Thiolate-protected Au₁₄₄ nanoclusters (NCs) are an intriguing member of the gold NC family. Their geometric structure, distinct electrochemical features, and susceptibility to structural rearrangement under the duress of ligand exchange have been studied. However, there are currently no established protocols for surface modification or tuning of their ligand shells post synthesis. Here, the direct synthesis of three regioisomers of azide-modified Au₁₄₄ NCs with 60 azide moieties, i.e., Au₁₄₄(SC₂H₄C₆H₄-N₃)₆₀, is reported, in which the azide functionality is located at the ortho-, meta-, or …

Establishing The Relative Composition Of Functionalized Thiols In Mixed Ligand Gold Nanoparticles By 1h-Nmr Spectroscopy, Matthias Carroll

All Master's Theses

Functionalized gold nanoparticles (AuNPs) are of interest for their optical and electrical properties, specifically the surface plasmon resonance phenomenon and potential applications for medicine and nano-circuitry. In this study, the ligand composition of small (~5 nm diameter) thiol functionalized AuNPs with mixed ligand monolayers was investigated to better understand how the molar feed ratio of ligands used during their synthesis influences the composition of ligands on the particle’s surface. The system under study was a combination of two ω-functionalized thiols, mercapto ethoxy ethoxy ethanol (MEEE) and mercapto pentyl trimethyl ammonium chloride (MPTMA). UV/Visible spectrophotometry, dynamic light scattering, and electron …

Preparation And Characterization Of Ruthenium-Gold Raman-Active Catalytic Surfaces, Thang Nguyen

Student Scholar Symposium Abstracts and Posters

Heterogeneous reactions at the gas-solid interface play a major role in many important industrial and environmental processes. These reactions typically rely on metal surfaces, to act as a catalyst between gas phase reactants and products. The catalysts lower the transition state barrier in the formation of the products. The mechanisms of reactions on catalysts is often not fully known due to the difficulty of observing the bond breakage and formation between gaseous molecules at the interface. One method in which the catalytic mechanism can be studied is by using Raman Spectroscopy. However, one drawback of this method is the fact …

Development Of Dihydrochalcone Functionalized Gold Nanoparticles For Augmented Antineoplastic Activity, Jason N. Payne

Masters Theses & Specialist Projects

Phloridzin, an antidiabetic and antineoplastic agent usually found in fruit trees, is a dihydrochalcone constituent that has a clinical/pharmaceutical significance as a sodiumglucose linked transport 2 (SGLT2) inhibitor. Phloridzin never experienced widespread clinical usage in the pharmaceutical market due to its side effects and poor bioavailability when compared to other antidiabetic therapeutics. The poor bioavailability is primarily attributed to the degradation of the glycosidic bond of the phloridzin, resulting in the formation of phloretin, the aglycone of phloridzin and glucose. While phloretin displays a reduced capacity of SGLT2 inhibition, this nutraceutical shows enhanced antineoplastic activity in comparison to phloridzin. Gold …

Design Rules For The Nucleation, Growth, And Encapsulation Of Gold Nanoparticles With Applications To Cancer Imaging, Matthew A. Wall

Dissertations, Theses, and Capstone Projects

Surface-enhanced Raman scattering (SERS) nanoparticles are exciting candidates for high-precision cancer imaging due to their highly specific spectral signature (Raman “fingerprint”) and propensity for passive targeting of cancerous tissues. However, the signal intensity of currently available SERS nanoparticles is insufficient for cancer imaging via passive targeting in most solid tumors. The overarching aim of this body of work is to develop a new generation of SERS nanoparticles with sufficiently low limits of detection to enable robust detection of various solid tumors in vivo.

The complexity of SERS nanoparticles requires significant advances to the theoretical and experimental understanding of metal …

Aging Of A Thermoelectric Module: Visualization Of Elemental Analysis, Stacie M. Dahl, Bernice E. Mills

Stacie M Dahl

Visualization of elemental composition is done to compare the surfaces of an aged thermoelectric module (TM) to an unaged one. The two modules’ exteriors are also compared to their interiors. Highlights of the analysis are presented here.

Electrochemistry Of Pani/Metal Composites In Basic Solutions, Tamthinhan Quy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Polyaniline (PANI) has been extensively investigated due to its unique conductivity, which is primarily dependent on the oxidation state of the material and the solution pH. PANI is an insulator when it is oxidized, and the solution pH exceeds four. Numerous attempts to extend PANI's conductivity to neutral and alkaline environments have been unsuccessful. However, our previous study has demonstrated that PANI/Pd composite is conductive and catalytically active in a basic solution, pH ∼ 12. Therefore, the conductivity and the electrochemical properties of PANI composites including PANI/Au, PANI/Pd and PANI/Pt were evaluated in basic solutions. The fundamental studies of PANI/metal …

Photothermal Reshaping Of Prismatic Au Nanoparticles In Periodic Monolayer Arrays By Femtosecond Laser Pulses, Wenyu Huang, Wei Qian, Mostafa A. El-Sayed

Wenyu Huang

Prismatic goldnanoparticles in the periodic monolayer arrays prepared with nanosphere lithography technique can be reshaped with femtosecond laser pulses at different powers and wavelengths. As the power density of 400 nm femtosecond laser increases, the prismatic particle tips begin to round and the overall particle shape changes from a prism to a sphere with a tripodal intermediate. The formation of the tip-rounded nanoprisms is probably due to the dewetting properties of gold on quartz surface and the low melting temperature at the tips. The formation of the tripodal nanoparticles is attributed to the inhomogeneous heating and lattice rearrangement of the …

Preparation And Application Of Gold_Film On The Surface Of Bacterial_Modified Carbon Paste Electrode, Rongzong Hu, Yanping Ruan, Hao Xu, Jinkun Fu, Weide Zhang, Wenyun Hu

Journal of Electrochemistry

A novel method for preparation of gold_film composed of ultra_fine gold particles was reported in this paper. The gold_film was prepared by electrochemical method on the surface of the paste electrode modified with the strain Bacillus sp. D01 which has strong ability to absorb and reduce Au3+. In addition, this paper reported an experimental method of determining trace amount of Cu2+ in water solution using cathodic stripping analysis to estimate the performances of the obtained gold_film. The experimental results indicated that this new method for preparation of gold_film is simple. The obtained gold_film electrode is stable and sensitive to determining …

A Preliminary Study Of Electrochemically Amplified Measurement Of Gold Electrodeposition, Bingwei Mao, Caihui Shi, Xiaoqin Li, Lihua Xiong

Journal of Electrochemistry

Gold electrodeposition onto a glassy carbon microelectrode is studied using an electrochemical amplification method. Taking the advantage that the electrochemical reduction of K2Cr2O7 has significantly higher reaction activity on gold electrode than carbon electrede,it is tentatively used to amplify the gold electredeposition current.The results show that there is a marked increase in current of gold electrodeposition in presence of K2Cr2O7 in comparison with that absent of K2Cr2O7.The electrochemical amplification method can be applied to study the electrodeposition of very in intial stage by choosing proper systems and improving experimental conditions.