This dissertation seeks to explore how physical forces, notably through the use of magnetic nanoparticles and applied fields, can influence the structural outcomes of colloidal crystals engineered with DNA. Chapter 1 describes how both DNA and magnetic fields can direct the assembly of nanoparticles into periodic and sometimes crystalline materials....
Proteins are known to have diverse biomedical functions and excellent catalytic performance; however, they are also fragile outside living cells, challenging their use in industrial applications. Metal-organic frameworks (MOFs) are highly porous crystalline materials that consist of metal cluster nodes and organic linkers. With their rigid structures, MOFs can effectively...
Noble metal nanoparticles (NPs) have shown promise as imaging agents, drug delivery platforms, and plasmonic sensors. Anisotropic gold NPs, such as gold nanostars, have particularly received attention due to their shape-dependent optical and spectral properties. With their 3D anisotropic structure with branches protruding into different directions and high surface areas,...
Recent progress in the field of nanomaterials has enabled significant advances in optoelectronic devices such as solar cells, light-emitting diodes, photocatalysts, and sensors. Nanoparticles feature superior optical and electronic properties that arise from quantum confinement and therefore cannot be attained used bulk materials. However, further developments in the field of...
Metallic conductivity and broken inversion symmetry were long thought to be contraindicated properties, under the assumption that long-range Coulombic interactions (screened by free charge carriers) were necessary for coordinated polar displacements. Within the past decade, the discovery of polar metals has prompted a rethinking of the relationship between metallicity and...
Two-dimensional (2D) covalent organic frameworks (COFs) are a class of crystalline polymer networks that polymerize and crystallize into layered structures, characterized by their atomically precise structure, permanent porosity and high modularity. Imine-linked COFs are one of the most important and promising classes of macromolecular sheets, which form by the condensation...
This thesis describes the synthesis and photophysical characterization of low-dimensionalmaterials—including thin-film semiconductors, colloidal quantum dots, and molecules—with the
broader motivation of integrating them into mixed-dimensional heterostructures with novel
responses to external stimuli. Due to their high surface area to volume ratio and incomplete
dielectric screening, mixed-dimensional heterostructures have high sensitivity...
Label-free assays, and particularly those based on the combination of mass spectroscopy with surface chemistries, enable high-throughput experiments of a broad range of reactions. However, these methods can still require the incorporation of functional groups that allow immobilization of reactants and products to surfaces prior to analysis. In this thesis,...
While Li-ion batteries are currently the preferred energy storage technology, multivalent alternatives such as Mg should be considered. Magnesium metal has a high volumetric capacity and has been shown to cycle with no dendrite formation. However, the highly charged Mg2+ ion cannot easily diffuse into the oxide cathodes favored in...
Nanoparticles (NPs) are emerging as attractive drug carriers in therapeutic and diagnostic applications. The physiochemical properties of NPs, such as particle size, shape, and surface chemistry, play important roles in the functions of engineered nanoconstructs−NP cores with surface ligands. Recent work has screened these properties by monitoring cellular uptake and/or...
The building blocks of life are proteins. These incredible nanostructures are responsible for forming the diverse infrastructure of living systems and for performing countless biological functions. In Nature, these materials and systems achieve structural complexity and function through highly regulated and controlled assembly of protein building blocks, driven by specific...
Recent progress in semiconductor synthesis and photophysics has revealed a host of new materials with exciting properties for applications in optoelectronic devices such as sensors, photovoltaics, solid state lighting, and more. One of the most significant recent additions to the field is the class of hybrid and inorganic materials that...
Realizing electromagnetic metamaterials which operate in the optical regime requires creating precise arrangements of sub-100 nm building blocks. As such, fabricating these materials using conventional lithographic methods is extremely costly. On the other hand, bottom-up assembly of nanoparticles into crystalline superlattices offers opportunities to explore the scalable fabrication of 2-...
Amyloid beta oligomers (AβOs) are a key instigator of neurodegeneration in Alzheimer’s disease (AD). The work presented in this thesis includes three disease-modifying approaches to disrupt pathological AβO-related mechanisms in AD: (1) inhibiting AβO buildup, (2) blocking AβO-induced tau phosphorylation, and (3) neutralizing AβOs. These three approaches were tested in...
Gold nanoparticles (AuNPs) display unique characteristics compared to their macro-counterparts that are dependent on shape, size, and attached surface molecules. Methods have been developed to precisely control both size and shape of AuNPs for specific applications. The biocompatibility, plasmonic properties, and ease of functionalization with thiolated molecules, make gold nanoparticles...
Functional electronic materials have transformed modern society toward a highly digitized and interconnected global community. The ever-growing demand for electronic devices with superior functionality poses a great challenge to the state-of-the-art field-effect transistors owing to the limited charge density afforded by silicon. Materials scientists and chemists have been working closely...
Biomedical imaging is an essential part of medicine that enables the non-invasive observation of biological phenomena. This, in turn, allows for more accurate and earlier diagnoses, monitoring of therapies, and even fundamental research into biological processes. Molecular imaging, a fast-growing subdiscipline of biomedical imaging, seeks to image biochemical processes at...
Amyloid beta oligomers (AβOs) are a key instigator of neurodegeneration in Alzheimer’s disease (AD). The work presented in this thesis includes three disease-modifying approaches to disrupt pathological AβO-related mechanisms in AD: (1) inhibiting AβO buildup, (2) blocking AβO-induced tau phosphorylation, and (3) neutralizing AβOs. These three approaches were tested in...
The construction of new C–C bonds remains a central facet of organic chemistry due to its critical role in the synthesis of pharmaceutical compounds and organic materials. Mild and selective methodologies are often required for efficient formation of these bonds in natural product total synthesis, medicinal chemistry campaigns, and more....
Understanding the mechanisms associated with chemical catalysis is vital for not only the rational improvement of their capabilities, but also for the advancement of the fundamental knowledge affiliated with the systems in question. These new insights can help predict new reactivities towards more challenging substrates which will allow for easier...
Semiconductor nanocrystals possess unique photophysical properties that make them desirable for many optoelectronic applications such as photovoltaics, LEDs, and quantum computing. When the size of a semiconductor is reduced to below the excitonic Bohr radius of the material, its carriers becomes quantum confined resulting in drastic changes to optical, electronic,...
Early transition metal organometallics chemisorbed on extremely Brønsted acidic sulfated metal oxides such as sulfated alumina (AlS) and sulfated zirconia (ZrS) produce highly active single-site catalysts for olefin polymerization, alkene and arene hydrogenation, and alkane hydrogenolysis, typically with a large percentage of catalytically significant sites. The low support conjugate basicity...
The physical boundary layer, or interface, between two different phases of matter is the site of chemical and physical processes that are critical to many research fields. Many of these interfaces contain electric charge, which influences the structure and composition of the interfacial region and the interactions between the interface...
Commercial agriculture and industrial manufacturing have contaminated freshwater sources with persistent organic pollutants, heavy metals, and radioactive species. Effective mitigation of this pollution is paramount to safeguarding human health, animal and aquatic life, and the environment. Conventional adsorbents such as activated carbon, metal oxides, resins, and polymers attain moderate to...
Oligonucleotides can be used to modulate the regulation of pathological genes that are associated with various diseases. However, due to biological barriers, efficient delivery of oligonucleotides, especially to extrahepatic tissues, remains a challenge. To overcome these barriers, multiple delivery strategies have been developed, ranging from medicinal chemistry to nanotechnology. Nanoparticle-based...
Soft materials are inherently fluxional, with morphologies and behaviors that are dictated by their solvation state. Thus, many organic systems cannot be reliably imaged by static dry state or cryogenic-transmission electron microscopy (TEM). This motivated us to pursue liquid cell (LC) TEM method development to study our own materials and...
The lanthanides, with their limited orbital effects and high oxophilicity, represent a class of catalytic metals highly distinguished from more commonly-utilized transition metals. Homogeneous lanthanide catalysts often afford high catalytic rates and impressive selectivity. However, challenges regarding the synthesis and utilization of highly air- and water-sensitive organo-lanthanide complexes have limited...
Polyolefins are the most versatile and widely used polymers worldwide. Depending on the polymer microstructure, polyolefins can exhibit a wide range of useful and tailored properties and applications. Metal-catalyzed coordinative olefin polymerization plays a center role in advancing polyolefin synthesis. This dissertation explores two strategies to modulate the polymer microstructures...
Spherical Nucleic Acids (SNAs) are unique class of nanomaterial characterized by a dense nucleic acid shell conjugated to a nanoparticle core. This radial orientation of oligonucleotides and architecture distinguishes SNAs from the components from which they are comprised. Specifically, unique chemical and biological properties emerge that are not observed with...
Uranium is a unique, multifaceted element that possesses rich chemistry and promise for challenging reactions. Pressing demands within nuclear stockpile stewardship and the nuclear energy sector call for development of this relatively understudied element. Uranium metal–organic frameworks (U-MOFs), a class of nanoscale hybrid materials, harness the exceptional attributes of uranium...
In this thesis, I present the development and benchmarking of several theoretical methods designed to enable the rigorous modeling of magnetic properties of molecules containing one or a few heavy atoms, particularly single-molecule magnets. The new methods use a full four-component treatment of relativity, allowing spin–orbit effects to be taken...
Self-assembled monolayers for matrix-assisted laser desorption/ionization mass spectrometry (SAMDI-MS) is a platform that combines self-assembled monolayers of alkanethiolates on gold and MALDI mass spectrometry analysis to report mass changes resulting from surface reactions. The synthetic flexibility of the monolayer and the use of mass spectrometry as a generalizable readout method...
Nanoparticle synthesis is capable of producing particles with any combination of structure, chemistry, size, shape, and surface. All of the different combinations of these physical properties can produce nanoparticles with almost countless materials properties suited for many applications. Given this interest in using nanoparticles in so many different fields, including...
This dissertation investigates the use of organic and semiconductor nanomaterials as chromophores in solar fuels production and energy transfer-mediated [2+2] cycloadditions. A series of novel N-annulated perylene chromophore amphiphiles was synthesized via a modular synthesis. These perylene amphiphiles were found to self-assemble in aqueous solution, forming extended ribbon-like nanostructures that...
One of the central challenges in solid-state chemistry is synthetic control over structure. Owing to limited reactivity of Pb with transition metals at ambient pressure and high temperature as well as the variety of properties that emerge from the few known binary transition-metal–Pb compounds, this research focuses on accessing and...
Heterogenous catalysis is the pillar of chemical production and a crucial aspect for optimization toward a sustainable future. To improve the current design of heterogeneous catalysts of maximal activity and product selectivity, gaining fundamental understanding of the catalytic active sites is crucial. The nature of active sites has been the...
Discrete molecules, linear and branched polymers, and disordered cross-linked networks are well studied objects of chemical synthesis. However, two-dimensional polymers (2DPs) have been long missing from this continuum of molecular architectures, both in chemical synthesis and in Nature. Recently, new polymerization strategies and characterization methods have enabled the unambiguous realization...
Neurons are sensitive to the mechanical properties of their environment and show better growth, survival and differentiation when they are cultured in soft environments with mechanical properties similar to those of the brain compared to other tissues. Within the central nervous system (CNS), there is also a range of mechanical...
Single-use plastic waste pollution will cause significant harm to the environment if left unaddressed. One possible mitigation strategy is to develop processes, e.g. catalytic hydrogenolysis, that can convert (i.e. upcycle) waste plastics into value-added products capable of participating in a circular economy. Platinum (Pt) catalysts on strontium titanate nanocuboid supports...
Oxide/aqueous and metal/metal oxide interfaces are essential for environmental remediation, catalysis, and corrosion inhibition, in addition to their potential implementation as energy transducers, consumer electronics, and coating products. While these interfaces are critically important, they are difficult to access experimentally under aqueous flow conditions. This thesis describes results obtained with...
Organic solar cells (OSC) are a next generation solar energy technology that offers the advantages of scalable fabrication, light weight, flexibility, and earth-abundant starting materials. Despite tremendous advances in OSC power conversion efficiency (PCE) over the last decade, active layer material selection and optimization is still largely empirical. In order...
When attached to another species (e.g. a nanoparticle), the sequence specificity of DNA can be repurposed to program interactions between such entities and to direct their formation into ordered structures. The research presented in this thesis aims to push the boundaries of structures that can be made via this approach....
Harnessing the metabolic potential of methanotrophic bacteria is a compelling strategy for the bioremediation of environmentally harmful methane gas. Methanotrophs can activate a 105 kcal/mol C-H bond in methane at ambient conditions using metalloenzymes called methane monooxygenases (MMOs). Particulate methane monooxygenase (pMMO) is a copper-dependent, membrane-bound enzyme that is the...
The properties of crystalline materials are controlled by their composition and by their structure, however, the structure of a crystal is only partly controlled by its composition. Development of specifically directed inorganic syntheses will require an understanding of the dynamics of crystal phase forming processes, especially those processes involved in...
The FDA approvals of afatinib and ibrutinib in 2013 led to a heightened interest in cysteine-reactive covalent inhibitors. However, there are few methods to discover new cysteine-reactive inhibitors for enzymes for which reversible binding scaffolds are not known. To this end, we rationally designed a chemical system to attach a...
Metalloporphyrins fulfill incredibly diverse chemical roles in biology and photocatalysis, where they act as photosensitizers, redox sites, substrate binding sites, and facilitators of long range electron transfer. Metalloporphyrin chemistry is uniquely tuneable through conformation and functionalization of the porphyrin ring, choice of metal, and interaction with the environment as these...
Surface-enhanced Raman spectroscopy (SERS) is a powerful technique for characterizing molecular systems. It combines the chemical selectivity of vibrational spectroscopy with plasmonic signal enhancement to achieve the ultimate limit of detection--a single molecule. By overcoming the effects of ensemble averaging, single molecule SERS (SMSERS) probes distributions in molecular interactions and...
Interprotein electron transfer (ET) occupies a central role in both chemistry and biology, as it is important in a variety of functions including cellular respiration, metabolism, and energy transduction during photosynthesis. Consequently, understanding the protein-protein recognition and docking that controls interprotein ET is an important field of scientific research.
One...
Raman spectroscopy is an established and versatile molecular sensing technique, but it is limited by its modest chemical sensitivity. Surface-enhanced Raman spectroscopy (SERS) can amplify otherwise weak normal Raman signals up to nine to ten orders of magnitude, giving rise to its application in many molecular sensing problems, including those...
Organic photovoltaics (OPVs) are an attractive solar energy technology for low-current applications. Herein is described the supramolecular design and methodology to manipulate intermolecular interactions in order to create an active layer in OPVs devices composed of crystalline and amorphous donor-acceptor domains, which has been proposed as the ideal morphology for...