The Study of Nano-optics In Hybrid Systems

In this thesis, we study the quantum light-matter interaction in polaritonic heterostructures. These systems are made by combining various nanocomponents, such as quantum dots, graphene films, metallic nanoparticles and metamaterials. These heterostructures are used to develop new optoelectronic devices due to the interaction between nanocomposites. Photoluminescence quenching and absorption spectrum are determined and an explanatory theory is developed for these polaritonic heterostructures. Photoluminescence quenching is evaluated for a graphene, metallic nanoparticle and quantum dot system. It is shown that average distance between nanocomposites or concentration of nanocomposites affect the output these system produced. Photoluminescence quenching was also evaluated for a metamaterial hybrid system. Lastly, the absorption spectrum of quantum dots was calculated in a quantum dot and metamaterial system. The metamaterial contained two surface plasmon modes which if in resonance with excitons of the quantum dot shown an enhancement in the absorption spectrum of the quantum dot

Thermal induced structural and magnetic transformations in Fe_{73.5−x}Ce_{x=0,3,5,7}Si_{13.5}B_9Nb_3Cu_1 amorphous alloy

Structural and magnetic properties of amorphous and partly crystallized Fe_{73.5−x}Ce_{x=0,3,5,7}Si_{13.5}B_9Nb_3Cu_1 alloys, were analysed in the temperature ranging from RT to 800 °C with scanning calorimetry and magnetometry. The Fe(Si) and Fe(B) structures were identified and characterised with set of crystallization temperatures and activation energies. Also, Curie temperatures for amorphous and for crystalline structures were determined and analysed as functions of Ce content

Site-Selective C-C Modification of Proteins at Neutral pH Using Organocatalyst-Mediated Cross Aldol Ligations

The bioconjugation of proteins with small molecules has proved an invaluable strategy for probing and perturbing dynamic biological mechanisms. The general use of chemical methods for the functionalisation of proteins remains limited however by the frequent requirement for complicated reaction partners to be present in large excess, and harsh reaction conditions which are incompatible with many protein scaffolds. Herein we describe a site-selective organocatalyst-mediated protein aldol ligation (OPAL) that affords stable carbon-carbon linked bioconjugates at neutral pH under biocompatible conditions. OPAL enables rapid chemical modification of proteins within an hour using simple aldehyde probes in minimal excess, and is utilised here in the selective affinity tagging of proteins in cell lysate. Furthermore we demonstrate that the b-hydroxy aldehyde product of the OPAL can be functionalised a second time at neutral pH in a subsequent organocatalyst-mediated oxime ligation. This tandem strategy is showcased in the ‘chemical mimicry’ of a previously inaccessible natural dual post-translationally modified protein integral to the pathogenesis of the neglected tropical disease Leishmaniasis. <br /

Design and Synthesis of Inhibitors of <i>Plasmodium falciparum N</i>-Myristoyltransferase, A Promising Target for Antimalarial Drug Discovery

Design of inhibitors for <i>N</i>-myristoyltransferase (NMT), an enzyme responsible for protein trafficking in Plasmodium falciparum, the most lethal species of parasites that cause malaria, is described. Chemistry-driven optimization of compound <b>1</b> from a focused NMT inhibitor library led to the identification of two early lead compounds <b>4</b> and <b>25</b>, which showed good enzyme and cellular potency and excellent selectivity over human NMT. These molecules provide a valuable starting point for further development