Several phosphonate-functionalized molecular
squares have been successfully synthesized,
and the fabrication of multilayer films
on both conductive and semiconducting
platforms has been demonstrated. These
films were grown using the well-documented
zirconium phosphonate multilayer method.
The layer-by-layer growth rate is uniform.
Experiments suggest, however, that the
molecular squares adopt a semi-collapsed...
The development and applications of
organic/DNA molecules for the use of DNA
detection systems are reported here. In particular,
two different hybrids are synthesized:
DNA/polymer hybrids and small-molecule
DNA hybrids. DNA/polymer hybrids are especially
useful considering that their functionality
may be varied according to the polymer
selected. The hybrids are...
Chemists and physicists have been interested
in the optical properties of metal nanoparticles
since the time of Michael Faraday.1
New approximation techniques for different
sizes and geometries have created renewed
interest in and investigation of these particles.
Many different arrays of particle extinctions
of various shapes and sizes have been...
While nanoscale device prototypes using
carbon nanotubes abound, no mass
production-scale technique exists for examining
properties of a batch of nanotubes.
Dielectrophoresis, on the other hand, has
received much attention in the press as a
method of separating and trapping particles.
In this research, a method of developing
mass production-scale...
Alzheimer’s disease (AD) is a progressive
mental disorder that affects 23 million people
worldwide. It is pathologically characterized
by amyloid plaques and tau tangles that
form in the brain. The hard, insoluble amyloid
plaques develop from the naturally
secreted amyloid beta peptide, which can
also assemble into toxic oligomeric forms...
Every year millions of Americans go to the
emergency room with symptoms of a heart
attack. More than half a million Americans
die each year of myocardial infarctions (MI)
caused by coronary heart disease (CHD).
CHD detection is currently limited to EKG
analyses of electrical signals generated by
the heart...
This project focused on the growth of Cu2O
nanocubes in microwells from nanoparticle
“seeds.” The seeds were first formed by the
reduction of copper sulfate with ascorbic
acid in the presence of the surfactant
poly(ethylene glycol) (PEG). Upon reaction
within the microwell, the seed solution
formed a larger single crystal....
Weak interactions in ligand-receptor
pairs are important in biological systems.
However, the energetics of these interactions
are often difficult to quantify for ligandreceptor
pairs. Weak interactions are a part
of reorganization energy, which plays a role
in electron transfer reactions. Under certain
conditions the rate of electron transfer
can be...
This work exploits the use of noble metal
nanoparticles to achieve sensitive and
selective detection of chemical and
biological analytes. The localized surface
plasmon resonance (LSPR) of these metal
nanoparticles is known to be sensitive to
shape, size, and the local environment.
Ag nanoparticles fabricated using the
nanosphere lithography (NSL)...
The use of a variable resistor-capacitor
(RC) bridge circuit was previously reported
to be a viable solution to the spurious
contribution of fringe capacitance during
nanoscale impedance microscopy (NIM).
In this paper, a refinement of this technique
combined with standard NIM is presented
as an impedance characterization tool for
organic...
Second harmonic generation (SHG),
a nonlinear optical tool, was used to
characterize DNA bound through a
chemical linker to the flat surface of a
hemispherical lens. Contact angle
measurements were used to guarantee
that the chemical linker did not hydrolyze
under experimental conditions. SHG
experiments followed the effects of salt...
Two-phase multiferroic nanostructures
have the potential to display magnetoelectricity
(ME) through interphase mechanical
coupling. Nanoscale ME-based technology
may lead to the next generation of computer
memory. In this research, soft electron
beam lithography (soft-eBL) was used to
fabricate submicron-sized structures of
cobalt ferrite (magnetostrictive) and barium
titanate (piezoelectric) as bottom...
Carbon nanotubes have been shown to
behave as very effective conductors and
semiconductors, but their electronic uses
are limited by how well metallic and
semiconducting nanotubes can be sorted.
Recent investigations have shown an
effective method of separating laser
ablation–produced carbon nanotubes by
electronic type. However, laser ablation
nanotubes are...
Surface patterns, formed by the coassembly
of cationic-anionic amphiphiles into
cylindrical micelles, were analyzed. The
competition between electrostatic forces
and the net incompatibility χ arising from
the different chemical natures of those
oppositely charged amphiphiles resulted in
the formation of segregated domains. These
surface domains are not macroscopically
segregated due...
Magnetic nanostructures are of great
interest as platforms for medical applications,
including biomedical imaging and
targeted cancer therapy. However, current
magnetic nanostructures are limited by
magnetic strength and insufficient
biocompatibility. In this research project,
significant progress was made to address
these confines, including 1) increasing
magnetic responsiveness by replacing the...
Weak, noncovalent interactions (dipoledipole
interactions, hydrogen bonding, and
Van der Waals forces) in ligand-receptor
pairs play a very important role in living
systems. A new way to study these
interactions is by using electron transfer
theory. The rate of electron transfer
between redox centers is dependent on
several factors, including...
Weak, noncovalent interactions (dipoledipole
interactions, hydrogen bonding, and
Van der Waals forces) in ligand-receptor
pairs play a very important role in living
systems. A new way to study these
interactions is by using electron transfer
theory. The rate of electron transfer
between redox centers is dependent on
several factors, including...
In this study, particle sorting and transportation
in Brownian liquids were explored by
translating an optical standing wave. The
standing wave is produced by crossing two
coherent beams of light, and determining
the resulting period by the angle of the
intersection. Adjusting the period and
velocity of wave ridges allows...
This paper reports the synthesis of an
azide-functionalized deoxynucleoside as a
precursor for azide-terminated oligonucleotides.
Also reported is the synthesis of an
acetylene-terminated precursor, which can
be used to make a diverse array of
silyl-protected acetylene-terminated small
molecule cores. Both of these precursors
serve as basic building blocks en route...
Pressure-assisted densification was used
by way of a hot press to optimize the
conditions of heat and pressure when
applied to anatase (TiO2). This study
optimized hot-pressing conditions, which
will be helpful when doping TiO2 because it
will allow optimization of bulk anatase for
transparent conductive oxide (TCO)
applications. Lessons...
Numerous studies have been structured to
investigate magnetoelectric multiferroic
materials, which possess simultaneous
ferroelectric and (anti)ferromagnetic
ordering. Bismuth ferrite (BiFeO3), referred
to as BFO, has drawn special attention
because of its unique ability to maintain both
electric and magnetic dipole moments at
room temperature. BFO shows great
potential to revolutionize...
When the Aß peptides aggregate into
soluble oligomeric clusters, they form
central nervous system neurotoxins known
as amyloid-ß-derived diffusible ligands
(ADDLs). The assembly of ADDLs is
currently thought to be a pathogenic
process in Alzheimer's disease (AD).
Understanding the molecular structure and
properties of ADDLs could prove useful in
the...
In many biological systems, ligand-receptor
pairs bind to each other via noncovalent
interactions such as hydrogen-bonding and
Van der Waals forces. This project’s method
of studying these interactions uses electron
transfer theory. When a receptor binds to a
redox-modified ligand, there is a change in
the reorganization energy of the...
In this research project, particle sorting of
Brownian liquids was explored by sweeping
two noncoherent pairs of parallel optical
standing waves in a translating medium.
Each wave was created by interfering two
coherent beams of light, and the resulting
fringe periods were determined by the angle
of intersection. Adjusting the...
Chip-based devices and biosensors
incorporate the attachment of biomolecules
at interfaces. The behavior of biomolecules
at the surface and interfaces differs from the
behavior of biomolecules in the bulk solution.
Surface-analysis techniques are therefore
required to characterize these interfaces.
Second harmonic generation (SHG) has been
used to characterize DNA on...
Bone-related problems have always been a concern in the medical field,
particularly how to heal and rebuild bones more rapidly when injuries
occur. A path to solving such problems might be to examine the
processes when bone develops in nature. This project aims at discovering
the chemical reactions that occur...
The formation of covalently grafted polymer brushes on silica (SiO2)
nanoparticles was achieved by surface-initiated reversible additionfragmentation
chain transfer (si-RAFT) polymerization. RAFT initiator
was first attached onto the surface of silica nanoparticles and then
examined by ultraviolet-visible spectroscopy (UV-vis) analysis. From the
resulting RAFT initiator-modified SiO2 nanoparticles, polymer chains
can...
Polymer nanoparticles (PNPs) were formed from amphiphilic diblock
copolymers consisting of a hydrophilic block with pendant polyethylene
glycol tosylate (PEG-OTs) groups and a hydrophobic block with pendant
terthiophene (TTT) groups. The resulting PNPs were characterized
using dynamic light scattering (DLS) and transmission electron
microscopy (TEM) to determine size, shape, and...
In the field of clinical diagnostics, biosensors are used to identify genetic
disorders by hybridizing a surface-bound DNA sequence with the
patient’s DNA. To further improve biosensor design, two nonlinear
optical techniques, sum frequency generation (SFG) and second
harmonic generation (SHG), were used to probe the orientation,
chirality, and surface...
Small, soluble, self-assembling peptide Aβ-oligomers, known as ADDLs
(amyloid-derived diffusible ligands), accumulate in the Alzheimer’s
disease (AD) brain as Aβ 12-mers and are thought to contribute to AD
neuropathological conditions. Unlike plaques, which were once thought
to cause neuronal death due to insoluble amyloid plaque deposits,
ADDLs initiate abnormal changes...
Semiconductor nanowires show promise for application in nanoscale
electronics, but the difficulty of forming low-resistance ohmic contacts
provides a challenge to their implementation. To improve the electrical
performance of lithographically defined nickel contacts, nickel-silicide/
silicon axial nanowire heterostructures were formed by controlled
partial silicidation. Prior to annealing, two-terminal silicon nanowire...