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...
The purpose of this study is to characterize
the nanometer-scale structure of an Al2O3-
W-Ge multilayer utilizing x-ray reflectivity.
Attributes such as layer thickness, density,
surface, and interface roughness are
determined and explained. The reasons for
using this particular multilayer are also
reviewed, as well as the benefits to science...
In this work, computational electrodynamics
is used to calculate extinction,
scattering, and local electric fields around
the transition metal nanoparticles. Rhodium
and ruthenium exhibit plasmon peak shifts
as a function of local refractive index
comparable to particles of silver and gold.1,2
In addition, the local fields calculated
indicate that Rh...
There is a continuing need for patterning
multifunctional materials to harness their
features and explore synergy among
diverse properties and phenomena. Soft
lithography, among various patterning
techniques, is a versatile method that can
generate inorganic patterns in a parallel
mode. Experimentation was performed
making use of flexible soft lithography to...
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...
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...
Oligonucleotide-functionalized gold
nanoparticles (DNA-Au NPs) find
ubiquitous use in various biomolecular
detection schemes due to their unique
chemical and physical properties. This
study investigates the effects of nanoparticle
size and concentration of salt in
solution on the DNA loading of the Au NP
surface. The DNA loading studies are
performed...
The effects of volumetric size-control
techniques on the photoinduced conversion
of silver colloids to triangular nanoprisms
were examined. It was hoped that through
the application of size-control techniques
on photocatalyzed reactions, a new method
of controlling particle dimensions could
be established. Initial work focused on
optimizing the synthesis procedure in...
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...
The need to improve sensing technology for
widespread application in everyday life is
fueling the development of diffraction-based
sensing, an optical sensing technique.
Selectivity and sensitivity issues must first
be resolved. Both selectivity and sensitivity
can be increased by using resonance conditions
— that is, using a probe wavelength
where...
Many studies have focused on harnessing
the extraordinary optical properties of
noble metal nanoparticles for the development
of biological and chemical nanosensors.
Metallic nanoparticles emulate
surface roughness, facilitating the coupling
of light to surface plasmon polaritons. The
excitation of the plasmons enhances the
electromagnetic field near the surface so
that...
The aim of this research was to investigate
the use of atomic force microscopy (AFM)
for the high-resolution imaging of collagen
fibers in aqueous media. Collagen plays a
vital role in many processes in vivo, especially
in structural integrity, yet few studies
have used AFM to investigate the structure
of...
This project involved the study of Brownian
motion of polystyrene microspheres in the
presence of gravity and a one-dimensional
sinusoidal optical potential generated by
the interference of two laser beams. An
exponential relationship was observed
between applied laser power and particle
residence time of individual interference
fringes. Increasing laser power...
In this study, ligands modified to contain
a metal ion were synthesized and their
electrochemical properties were examined
alone and in the presence of a protein. We
chose to use avidin and biotin as a model
system. Probes have been developed in
which biotin is modified to coordinate to
a...
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)...
In this experiment, the optical properties
of several spherical nanoparticles were
observed. Particles were modeled using
Mie theory, a set of equations that calculate
the extinction coefficient of virtually any
spherical particle. Initially this theory was
used to model solid particles made of noble
metals. As time passed, its scope...
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...
The bio-barcode assay is a nanotechnology-based
method for capturing and
detecting proteins. It shows extraordinary
sensitivity in detecting certain antigens at
extremely low concentrations, now without
the use of the polymerase chain reaction
(PCR). This assay uses disease identification
biomarkers that cannot be used in the
conventional assays of today....
This report describes the development of
bioorganic small-molecule complexes for the
directed assembly of functional nanomaterials.
In particular, it examines the synthesis of
small acetylene-based organic precursors for
attaching DNA to form DNA/organic hybrids.
This work continues previous studies
demonstrating how DNA/polymer hybrid
composites have sharper melting points than
DNA...