Surface plasmon resonance (SPR) biosensors have attracted great attention in scientific research in the past three decades. Extensive studies on the immobilisation of biorecognition elements have been conducted in pursuit of higher sensitivity, but trialled formats have focussed on a thin layer modification next to the plasmon film, which usually requires in situ derivatization. This thesis investigates an 'off-chip' immobilisation strategy for SPR biosensing using silica particles and considers the implications of a particle-modified evanescent field on the signal amplitude and kinetics, for an exemplar affinity binding between immobilised IgG and its anti-IgG complement. Submicron silica particles were synthesized as carriers for the bio-recognition elements. They were then immobilised to form a sub-monolayer on the gold film of an SPR biosensor using two methods: thiolsilane coupling and physical adsorption aided by mechanical pressure. The bio-sensitivity towards an antigen/antibody interaction was lower than an SPR biosensor with an alkanethiolate SAM due to the difference in ligand capacity and position in the evanescent field. The binding kinetics of antigen/antibody pair was found to follow the Langmuir model closely in a continuous flow configuration but was heavily limited by the mass transport from the bulk to the sensor surface in a stop-flow configuration. A packed channel configuration was designed with larger gel particles as ligand carriers, packed on top of a gold film to create a column-modified SPR biosensor. This sensor has comparable bio-sensitivity to the previous sub-monolayer particle-modified systems, but the binding and dissociation of the analyte was heavily dependent on mass transport and binding equilibria across the column. A bi-directional diffusion mechanism was proposed based on a two-compartment mass transport model and the expanded model fitted well with the experimental data. The column-modified sensor was also studied by SPR imaging and analyte band formation was observed and analysed. Using the lateral resolution, a multiplexing particle column configuration was explored, and its potential in distinguishing a multicomponent analyte.

In this thesis study, the surface/interface plasmon excitations in different Si nanostructures were revealed through the EELS study in TEM/STEM. In the case of the planar boundary such as the wedge-like specimen, the spatially resolved EELS results disclose the dependence of the intensity and the position of the interface plasmon peak on the sample thickness. In the case of the Si-core/ SiO2-shell nanoparticles, we found that the SP/IP peak will firstly red-shifts with the increase of the SiO2 shell thickness and eventually levels off . As the aspect ratio of the Si nanoparticles increases, (from spherical particle to nanorod and nanowire), the SP/IP will split into two branches: transverse and longitudinal modes. We also found the intensity ratio of the transverse/longitudinal mode excitations depends on the diameter of the Si core size in the nanostructures. In the one-dimensional interacting Si nanoparticle chains, the Si nanoparticles were embedded in the SiO 2 shell, the splitting of the SP excitation into transverse and longitudinal modes was also observed. As the inter-particle distance reduces to several nanometers, the coupling of the IP excitation between the adjacent particles becomes significant, and results in the local field enhancement in-between the two particles. This is directly visualized using EFTEM imaging in TEM/STEM. / Surface/interface plasmons (SP/IP) are the plasmons confined at specific boundaries, describing the surface/interface charge density oscillation. They are generated when the scattered electromagnetic wave with its scattering vector component parallel to the boundary propagates along the surface/interface. Study of surface plasmon resonance in noble metals such as gold and silver nanoparticles have started decades ago, and recent interests are focused on the plasmonic properties of individual nanoparticles, as enabled by the size/shape control in the nanostructure growth and advances made in the characterization methodologies. Besides the noble metals, semiconductor such as silicon also attracts much attention for its plasmonic behavior. The surface/interface plasmon resonance frequency of Si-based nanostructures occurs at relatively higher energies (compared to Au and Ag), making it a perfect system to be studied using electron energy loss spectroscopy (EELS) based techniques. When performed in a scanning transmission electron microscope (STEM), such a technique enjoys excellent spatial resolution, and can map the local plasmonic properties of individual nanostructures. / The plasmon excitation depends sensitively on not only the material dielectric properties but also the geometrical configurations of the material. In the present thesis work, silicon-based nanostructures with planar, spherical, and cylindrical boundaries were investigated using both experimental and theoretical approaches, with focus on the plasmon oscillation originating from the Si/SiO 2 interface. The specimens employed include silicon/silica thin films, Si-core/SiO2-shell nanoparticles with different aspect ratios and spherical-shaped nanoparticle chains, as well as Si-core/SiO2-shell nanocables. / Wang, Xiaojing = 低維硅納米結構表界面等離激元之研究 / 王笑靜. / Adviser: Li Quan. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 118-122). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Wang, Xiaojing = Di wei gui na mi jie gou biao jie mian deng li ji yuan zhi yan jiu / Wang Xiaojing.

Shao, Lei = 金顆粒納米晶中角度、能量和空間位置分辨的表面等離子共振耦合 / 邵磊. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references. / Abstracts in English and Chinese. / Shao, Lei = Jin ke li na mi jing zhong jiao du, neng liang he kong jian wei zhi fen bian de biao mian deng li zi gong zhen ou he / Shaolei. / Abstract --- p.1 / 摘要 --- p.iii / Acknowledgement --- p.v / Table of Contents --- p.vii / List of Figures --- p.ix / List of Tables --- p.xiv / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Localized Surface Plasmon Resonances of Noble Metal Nanocrystals --- p.3 / Chapter 1.1.1 --- Dielectric Functions of Noble Metal Nanocrystals --- p.3 / Chapter 1.1.2 --- Absorption and Scattering of Light by Noble Metal Nanoparticles --- p.7 / Chapter 1.2 --- Coupling between Localized Surface Plasmons --- p.14 / Chapter 1.2.1 --- Theoretical Treatments for Plasmon Coupling --- p.14 / Chapter 1.2.2 --- Unique Properties Resulting from Plasmon Coupling --- p.15 / Chapter 1.2.3 --- Applications Based on Plasmon Coupling --- p.17 / Chapter 1.3 --- Outline of Thesis --- p.18 / Chapter 2. --- Growth of Gold Nanocrystals and Characterization Techniques --- p.26 / Chapter 2.1 --- Growth of Gold Nanocrystals --- p.26 / Chapter 2.2 --- Characterization Techniques --- p.29 / Chapter 3. --- Surface Plasmon Coupling in Homodimers of Elongated Gold Nanocrystals --- p.34 / Chapter 3.1 --- Formation of Homodimers of Elongated Gold Nanocrystals --- p.35 / Chapter 3.2 --- Angle-Resolved Plasmon Coupling in Gold Nanorod Dimers --- p.37 / Chapter 3.2.1 --- Experimental Results --- p.39 / Chapter 3.2.2 --- FDTD Calculations --- p.43 / Chapter 3.2.3 --- Dipolar Modeling --- p.49 / Chapter 3.3 --- Effect of the Head Shape on the Plasmon Coupling --- p.57 / Chapter 3.4 --- Summary --- p.60 / Chapter 4. --- Surface Plasmon Coupling in Heterodimers of Gold Nanocrystals --- p.64 / Chapter 4.1 --- Formation of Heterodimers of Gold Nanocrystals --- p.65 / Chapter 4.2 --- Energy-Resolved Plasmon Coupling in Gold Nanorod Heterodimers --- p.67 / Chapter 4.3 --- Position-Resolved Plasmon Coupling in Gold Nanorod-Nanosphere Heterodimers --- p.70 / Chapter 4.3.1 --- Experimental Results --- p.71 / Chapter 4.3.2 --- FDTD Calculations --- p.75 / Chapter 4.4 --- Summary --- p.83 / Chapter 5. --- Summary and Conclusion --- p.87

Yu, Tsz Tat. / "December 2010." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 143-147). / Abstracts in English and Chinese. / Abstract --- p.2 / 摘要 --- p.4 / Acknowledgements --- p.5 / List of Figures --- p.6 / List of Tables --- p.12 / List of Abbreviations --- p.13 / Table of Contents --- p.14 / Chapter Chapter 1 --- Introduction --- p.17 / Chapter Chapter 2 --- Literature Review / Chapter 2.1 --- Surface Plasmon Wave --- p.19 / Chapter 2.2 --- Excitation of Surface Plasmon --- p.23 / Chapter 2.3 --- Surface Plasmon Coupling --- p.24 / Chapter 2.4 --- Surface Plasmon Resonance Detection Techniques --- p.33 / Chapter 2.5 --- Applications of SPR biosensors --- p.39 / Chapter Chapter 3 --- Theory of irradiance modulator / Chapter 3.1 --- Polarization --- p.44 / Chapter 3.2 --- Optical polarizer --- p.45 / Chapter 3.3 --- Liquid Crystal Modulator --- p.49 / Chapter 3.4 --- Irradiance Modulator --- p.52 / Chapter Chapter 4 --- LCM characterization / Chapter 4.1 --- Single LCM Transmittance driven by pure square wave --- p.66 / Chapter 4.2 --- Single LCM Reflectance driven by 50:50 STAM wave --- p.70 / Chapter 4.3 --- Multiple LCMs Reflectance driven by 90:10 STAM wave --- p.73 / Chapter Chapter 5 --- Background of phase measurement / Chapter 5.1 --- From holography to shearography --- p.77 / Chapter 5.2 --- From static Mach-Zehnder interferometer to differential-phase Mach-ZehnderZ interferometer --- p.81 / Chapter 5.3 --- From differential-phase imaging to pixel-referencing imaging --- p.86 / Chapter Chapter 6 --- Pixel-referencing data processing / Chapter 6.1 --- Background --- p.89 / Chapter 6.2 --- Procedures --- p.94 / Chapter 6.3 --- Experimental results --- p.98 / Chapter 6.4 --- Sensor resolution --- p.116 / Chapter 6.5 --- Performance comparison between single-beam LCM and Mach Zehnder configuration --- p.119 / Chapter Chapter 7 --- Discussions / Chapter 7.1 --- Experiment precautions --- p.136 / Chapter 7.2 --- Linear curve fitting --- p.137 / Chapter 7.3 --- Hardware limitation: Low frame rate --- p.138 / Chapter 7.4 --- Matching oil and glass slide --- p.139 / Chapter Chapter 8. --- Conclusions --- p.141 / References --- p.143 / Appendix / Chapter A1 --- "Concentration, Refractive Index and Dielectric constant of Sodium Chloride Solution (20°C)" --- p.148 / Chapter A2 --- Liquid Crystal Modulator Specification --- p.149 / Chapter A3 --- "Digital-to-analogue Converter Device (NI, PCI6036E) Datasheet" --- p.150 / Chapter A4 --- "CCD Camera (Lumenera, Infinity) Datasheet" --- p.151 / Chapter A5 --- Flow chart of SPR phase extraction --- p.152 / Chapter A6 --- Codes of SPR phase extraction in modules --- p.153

Nobel metal nanoparticles that exhibit plasmon resonances in the visible and near infrared have been of great interest in recent years. Strong light-matter interactions on the nanoscale have a range of interesting properties that may be useful in applications in medicine, sensing, solar energy harvesting and information processing. Depending on the application, particle materials and geometries can be optimized for performance. A novel method of quantifying individual nanoparticle scattering cross-sections by comparing experiments with analytical theory for gold nanospheres is proposed and utilized. Results show that elongated particles scatter very brightly for their volumes. This brightness is due to a strong longitudinal plasmon resonance that occurs in the near infrared – where gold has minimal loss. Elongated particles, such as nanorods, are therefore, ideal for applications that rely on particles scattering brightly in small spaces, such as biological imaging. Next, gold nanobelts are discussed and characterized. These novel structures are akin to nanowires, but with a small, rectangular cross-sectional geometry. Gold nanobelts are shown to exhibit a strong transverse resonance that has never been reported previously in nanowires. The transverse resonance is shown to shift linearly with crosssectional aspect ratio. Other interesting products from the nanobelt synthesis, tapered and split nanobelts, are discussed. Gold nanobelts also support longitudinal propagating plasmons, and have the smallest cross-sectional area of any elongated plasmonic structure that has been reported to do so. By analyzing the output tip signal of propagating plasmons for nanobelts of different lengths, the decay length is measured. Finite Difference Time Domain simulations and polarization measurements show the fundamental, azimuthally symmetric mode is very strong for thin structures such as these, but decays much more quickly than a higher-order mode, which begins to dominate at longer lengths. The cross-sectional mode area is given, illustrating the high confinement of plasmons in these structures. A figure of merit that takes into account both confinement and propagation length is calculated to be 1300 for the higher-order mode, the highest reported for nanoscale plasmonic waveguides. The high figure of merit makes gold nanobelts excellent candidates for studying strong coupling between plasmonic structures and objects that exhibit quantum behavior.

A new method is developed referred to as Gold Nanorod Optical Modeling Equations (GNOME) for determining the average aspect ratio of gold nanorods in solution. In this method, the observed inhomogeneously broadened optical spectrum is fitted to a number of calculated homogeneously broadened spectra with different aspect ratios having different contributions. From this method, the average aspect ratio is determined. This is a more accurate than the presently used method of TEM. The surface plasmon enhanced fluorescence spectra of gold nanorods are calculated as a function of the aspect ratio and compared to experimental spectra. In this calculation, the inclusion of both the aspect ratio distribution calculated from the GNOME method as well as the incorporation of the intrinsic fluorescence of bulk gold are found necessary to model the enhanced fluorescence spectrum of gold nanorods using previously published equations. The enhanced spectrum decreases rapidly as the aspect ratio increases and the surface plasmon band shift away from the gold interband absorption. Photochemical methods are used to synthesize silver nanoparticles on silica surfaces and gold nanoparticles in solution. The formation silver nanoparticles utilizes benzophenone as a photosensitizing agent to initiate the reaction. The effects of the light source and irradiation time are investigated. The presence of different forms of silica are investigated in the formation of metal nanoparticles. This method produced silver nanoparticles on silica that can be in the form of film or powder that are useful in heterogeneous catalysis. Direct photochemical methods are applied to generate gold nanoparticles from chloroauoroic acid in ethylene glycol in the presence of polyvinylpyrrolidone as a capping material. A detailed mechanism of the formation of the gold nanoparticle is determined. This is done by following the kinetics of formation of the gold nanoparticles after irradiation under different conditions. The disproportionation of the gold ions as well as their reduction by ethylene glycol is found to be important in the formation of the nanoparticles. Photochemical synthesis provides room temperature techniques to generate metal nanoparticles in a variety of environments.

Cellulose is the most plentiful biopolymer on the planet, and as such, is a large potential energy source. Converting cellulose into ethanol first requires the disruption of the crystallinity of cellulose fibers and subsequent hydrolysis into glucose. The glucose can then be fermented, producing ethanol. The conversion of cellulose fibers to glucose is an energy intensive and costly step, which is a barrier to industrial production of cellulosic ethanol. The use of enzymes to facilitate this conversion is a promising approach. In the present study, the action of individual enzymes and combinations of enzymes from the Hypocrea jecorina secretome on bacterial cellulose fibers has been studied, to better understand their individual and synergistic action. I have used a custom Surface Plasmon Resonance imaging (SPRi) device to measure changes in the thickness of cellulose fiber coverage of a thioglucose-functionalized gold substrate upon exposure to enzymes. The cellulose fibers were deposited using a Langmuir-Blodgett technique, resulting in non-uniform cellulose coverage of the substrate. By defining local Regions of Interest (ROIs) of the cellulose-covered gold film, and by measuring the SPR curves at elevated temperature for the ROIs as a function of time, we are able to determine the rate and extent of degradation of the cellulose fibers within individual ROIs. We have fit the change in SPR angle over time after exposure to enzyme to an exponential decay function that allows us to determine the average time constant of action of these enzymes on the deposited cellulose fibers. We have used the above procedure to measure the average time constants of action and the average degradation fraction (the change in average thickness divided by the initial average thickness) of cellulose fibers exposed to CBH-1, CBH-2, and EG-1, as well as combinations of these enzymes. We have measured an increase in the average degradation fraction and a decrease in the average time constants of action for cellulose fibers exposed to 23 μg/mL CBH-2 compared to fibers exposed to the same concentration of CBH-1. Additionally, for concurrent exposure of CBH-1 and EG-1 (with individual concentrations of 23 μg/mL), as well as concurrent introduction of CBH-1, CBH-2 and EG-1, we observed increases in the average degradation fraction and decreases in average time constants relative to the values measured for the individual enzymes. These measurements allow us to determine the relative activity of these enzymes and they demonstrate cooperativity and complementarity of action of the different enzymes.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Canterbury, 2008. / Typescript (photocopy). "January, 2008." Includes bibliographical references (p. 179-206). Also available via the World Wide Web.

Thesis (Ph. D.)--Ohio State University, 2008. / Title from first page of PDF file. Includes vita. Includes bibliographical references (p. 110-118).