Nanoscience and Nanotechnology Commons^™

Engineering Zinc Oxide Nanoparticles To Be Used As Nanofertilizers, Zeinah Elhaj Baddar

Theses and Dissertations--Plant and Soil Sciences

Zinc deficient soils, or soils with low Zn bioavailability, are widespread, which exacerbates Zn deficiency in human as crops grown on these soils have low Zn content. Often crop yields are also compromised. Fertilizers based on soluble Zn salts often have limited efficacy in such soils. In this research, we evaluate the performance of polymer coated and bare ZnO nanoparticles (NPs) in an attempt to overcome limitations of soluble Zn salts in alkaline soils. We first synthesized 20-30 nm bare ZnO NPs with different surface chemistries to impart colloidal stability to the particles. Bare ZnO were treated in phosphate solution …

Surface And Structural Modification Of Carbon Electrodes For Electroanalysis And Electrochemical Conversion, Yan Zhang

Theses and Dissertations--Chemistry

Electrocatalysis is key to both sensitive electrochemical sensing and efficient electrochemical energy conversion. Despite high catalytic activity, traditional metal catalysts have poor stability, low selectivity, and high cost. Metal-free, carbon-based materials are emerging as alternatives to metal-based catalysts because of their attractive features including natural abundance, environmental friendliness, high electrical conductivity, and large surface area. Altering surface functionalities and heteroatom doping are effective ways to promote catalytic performance of carbon-based catalysts. The first chapter of this dissertation focuses on developing electrode modification methods for electrochemical sensing of biomolecules. After electrochemical pretreatment, glassy carbon demonstrates impressive figures-of-merit in detecting small, redox-active …

Thermodynamics And Kinetics Of The Three-Way Junction Of Phi29 Motor Prna And Its Assembly Into Nanoparticles For Therapeutic Delivery To Prostate Cancer, Daniel W. Binzel

Theses and Dissertations--Pharmacy

The emerging field of RNA nanotechnology necessitates creation of functional RNA nanoparticles, but has been limited by particle instability. Previously, it was found the three-way junction (3WJ) of the Phi29 DNA packaging motor pRNA was found to be ultra-stable and assemble in solution without the presence of metal ions. The three-way junction is composed of three short oligo RNA strands and proven to be thermodynamically stable. Here the assembly mechanism, thermodynamic and enzymatic stabilities, and kinetics are examined in order to understand the stability behind this unique motif. Thermodynamic and kinetics studies found that the pRNA 3WJ formed out of …

Addressing Public Health Risks Of Persistent Pollutants Through Nutritional Modulation And Biomimetic Nanocomposite Remediation Platforms, Bradley J. Newsome

Theses and Dissertations--Chemistry

Due to their relative chemical stability and ubiquity in the environment, chlorinated organic contaminants such as polychlorinated biphenyls (PCBs) pose significant health risks and enduring remediation challenges. Engineered nanoparticles (NPs) provide a novel platform for sensing/remediation of these toxicants, in addition to the growing use of NPs in many industrial and biomedical applications, but there remains concern for their potential long-term health effects. Research highlighted herein also represents a transdisciplinary approach to address human health challenges associated with exposure to PCBs and NPs. The objectives of this dissertation research are two-fold, 1) to develop effective methods for capture/sensing and remediation …

Influence Of Surface Modification On Properties And Applications Of Complex Engineered Nanoparticles, Binghui Wang

Theses and Dissertations--Chemical and Materials Engineering

Complex engineered nanoparticles (CENPs) are being used on various applications. Their properties are different from those of neat nanoparticles. The dissertation explores these differences from four aspects: 1) Modify carbon nanomaterials’ inert surfaces and investigate the effect on thermal and rheological behavior of their dispersions; 2) Generate self-assembly bi-layer structure of oxide nanoparticles via surface modification; 3) Study interaction between lysozyme and different surface-charged ceria nanoparticles; 4) Investigate the biodistribution and transformations of CENPs in biological media.

An environment-friendly surface modification was developed to modify surfaces of carbon nanomaterials for increasing their affinity to non-polar fluid. It can offset formation …

Transformations, Bioavailability And Toxicity Of Manufactured Zno Nanomaterials In Wastewter, Sewwandi Rathnayake

Theses and Dissertations--Plant and Soil Sciences

In order to properly evaluate the ecological and human health risks of ZnO Manufactured nanomaterials (MNMs) released to the environment, it is critical to understand the likely transformation products in the wastewater treatment process and in soils receiving biosolids. To address this critical knowledge gap, we examined the transformation reactions of 30 nm ZnO MNMs in single component and multi-component systems, with phosphate and natural organic matter (NOM). We also assessed the influence of nano ZnO transformation on the bioavailability, and toxicity of ZnO transformation products to Triticum aestivum. The data revealed that ZnO MNMs react with phosphate at …

Structural Basis Of Substrate Recognition In Thimet Oligopeptidase And Development Of Nanoparticles For Therapeutic Enzyme Delivery, Jonathan Mark Wagner

Theses and Dissertations--Molecular and Cellular Biochemistry

Neuropeptidases are responsible for degradation of signaling peptides in the central nervous system and periphery. Some neuropeptidases have also been shown to play a role as part of the cell’s hydrolytic machinery responsible for breaking down proteins and peptides into amino acids, and these enzymes therefore influence small peptide availability for antigen presentation. A better understanding of how neuropeptidases recognize their substrates could lead to therapeutics that modulate the activity of these important enzymes. Alternatively, re-engineering these enzymes to selectively hydrolyze undesirable peptides could make them attractive as therapeutics themselves. A key question in understanding the activity of these enzymes …

Investigations Of Oxidative Stress Effects And Their Mechanisms In Rat Brain After Systemic Administration Of Ceria Engineered Nanomaterials, Sarita S. Hardas

Theses and Dissertations--Chemistry

Advancing applications of engineered nanomaterials (ENM) in various fields create the opportunity for intended (e.g. drug and gene delivery) or unintended (e.g. occupational and environmental) exposure to ENM. However, the knowledge of ENM-toxicity is lagging behind their application development. Understanding the ENM hazard can help us to avoid potential human health problems associated with ENM applications as well as to increase their public acceptance. Ceria (cerium [Ce] oxide) ENM have many current and potential commercial applications. Beyond the traditional use of ceria as an abrasive, the scope of ceria ENM applications now extends into fuel cell manufacturing, diesel fuel additives …