Date of Award
Doctor of Philosophy (PhD)
Nuclear magnetic resonance (NMR) spectroscopy is one of the most powerful analytical tools and has been widely used to quantitively and qualitatively analyze compositional and structural information of various molecules. Since the first discovery of NMR, its applications have been continuously expanded into various fields including chemistry, biology and medicine. For example, NMR has been widely used to elucidate structure for organic and inorganic compounds and also provide structural, kinetic, and dynamic information for biological macromolecules, such as proteins, DNA and RNA. One important application of NMR spectroscopy is to investigate the interaction between nanoparticles and biomolecules owing to its non-destructive characteristic and providing atomic level information. Up to now, there are many NMR methods employed to study the interaction between nanoparticles and molecules. The NMR method we have discussed in this thesis is Saturation-Transfer Difference (STD) NMR spectroscopy. At the end of Chapter One, a detailed explanation of STD NMR spectroscopy is discussed. The main objective of this thesis is to discuss the development and application of NMR techniques, in particular STD NMR spectroscopy, to study the interaction between small molecules and nanoparticles. In this thesis, the application aspects of STD NMR spectroscopy include two parts: (1) studying the interaction between xanthene dyes and two types of polystyrene nanoparticles functionalized with carboxylate or amidine groups on the surface, which is discussed in Chapter Two. In addition, results of NMR spectroscopy have been compared with that of two optical methods (UV-Vis spectroscopy and Fluorescence spectroscopy); (2) probing the driving forces for binding between amino acids and polystyrene nanoparticles, which is discussed in Chapter Three. A series of experiments is executed to verify the existence of electrostatic effects and hydrophobic effects between nanoparticles and amino acids. The development aspect of STD NMR spectroscopy involves 13C STD NMR spectroscopy using the insensitive nuclei enhanced by polarization transfer (INEPT) pulse sequence (STD-INEPT), which is discussed in Chapter Four. Here, we have performed STD-INEPT method and explored its application under different conditions. Comparing with the 1H STD-NMR and STD-HSQC methods, the advantages and disadvantages of STD-INEPT method have been discussed.
Xu, Hui, "The Development and Applications of Nuclear Magnetic Resonance Spectroscopy in Surface Interaction of Nanoparticles" (2021). All Dissertations. 2775.