| dc.description.abstract | Unconventional nanofabrication techniques; both those which have been newly
developed and those under development, had brought inexpensive, facile, yet high
quality means to fabricate nanostructures that have feature sizes of less than 100 nm in
industry and academia. This dissertation focuses on developing unconventional
fabrication techniques, building studying platforms, and studying the mechanisms
behind them.
The studies are divided into two main facets and four chapters. The first facet, in
Chapter II and Chapter III, deals with the research and development of different
nanofabrication techniques and nanostructures. These techniques include litho-synthesis,
colloidal lithography, and photolithography. The nanostructures that were fabricated by
these techniques include the metal nanoparticle arrays, and the self-assembled CdSe
nanoring arrays. At the same time, the dissertation provides mechanisms and models to
describe the physical and chemical nature of these techniques.
The second area of this study, in Chapter III to Chapter V, presents the
applications of these nanostructures in fundamental studies, i.e. the mechanisms of
plasmon enhanced fluorescence and photo-oxidation kinetics of CdSe quantum dots, and
applications such as molecular sensing and material fabrication. More specifically, these
applications include tuning the optical properties of CdSe quantum dots, biomodification
of CdSe quantum dots, and copper ion detection using plasmon and photo
enhanced CdSe quantum dots.
We have successfully accomplished our research goals in this dissertation.
Firstly, we were able to tune the emission wavelength of quantum dots, blue-shifted for
up to 45 nm, and their surface functionalization with photo-oxidation. A kinetic model
to calculate the photo-oxidation rates was established. Secondly, we established a
simple mathematical model to explain the mechanism of plasmon enhanced fluoresce of
quantum dots. Our calculation and experimental data support the fluorescence
resonance energy transfer (FRET) mechanism between quantum dots and the metal
nanoparticles. Thirdly, we successfully pattered the CdSe quantum dots (diameter ~4
nm) into nanorings with tunable diameters and annular sizes on different substrates. We
also established a physical model to quantitatively explain the mechanism with the
forces that involved in the formation of the nanorings. | en |
