Date of Award
Master of Science
Dr. Silvia Mittler
Proteins are essential ingredients of every living cell and organism and display a special property called optical activity, meaning their ability to turn the polarization direction of linearly polarized light in a very particular fashion. The magnitude of this polarization turning angle depends on the nature of the amino acid side chain. The temperature, the wavelength of the light used in the measurement, the specific optical activity of the molecule, the concentration and the interaction length of the light beam applied through the specimen can also affect optical rotation behavior. In previous work, a simple laser fiber polarimeter based on a liquid-core silica hollow optical fiber waveguide with an extremely small volume (39 pi) but a light interaction length of 2.2 m was bulit to investigate the optical activity of chiral molecules. In this thesis the fundamental liquid-core fibre polarimeter setup was employed to test and characterize fused silica and teflon AF fibres in different lengths and it was proved that the fibre length for the silica and Teflon AF fibre could be extended up to 5 and 2 m, respectively. Clearly path length is the most important advantage of this polarimeter which led to development of a new spectral polarimeter system to take advantage of the optical rotatory dispersion of chiral molecules e.g. proteins. This new setup has been built and in order to gain the best efficiency from the spectral polarimeter setup and optimize the function of it, the setup was characterized and optimized in three parts: the light source, temperaure stabilized box and the detection system. To prove the spectral fibrer polarimeter works properly and shows an improvement due to the enhanced sample interaction length, the polarimeter was tested with a chiral material in different concentrations and fibre length. A detection resolution in order of microdegrees and a limit of detection (LOD) of 0.3 and 0.1 /¿M for a 220.4 and 428.8 cm fiber were found with this new spectral polarimeter which confirmed the enhancement of sensitivity. The optical rotation changes in collagen solution were invetigated by this new technology.
Gouran Orimi, Maryam, "Development of High Sensitivity Spectral Fiber Polarimeter for Protein Investigations" (2011). Digitized Theses. 3332.