Raman Characterization of Colloidal Nanoparticles using Hollow-core Photonic Crystal Fibers

• Main Author: Mak, Siu Wai Jacky
• Other Authors: Helmy, Amr S.
• Language: en_ca
• Published: 2011
• Subjects: Raman; Nanoparticles; Photonic Crystal Fiber; Sensing; Liquid core fiber; Microstructured fiber; 0544; 0542; 0541
• Online Access: http://hdl.handle.net/1807/31328

This Masters thesis investigates the ligand–particle binding interactions in the thiol–capped CdTe nanoparticles and dye adsorbed gold nanoparticles. In the CdTe nanoparticles, Raman modes corresponding to the CdTe core, thiol ligand and their interfacial layers were observed and correlated to the different nanoparticle properties. To the best of our knowledge, this is the first time that such strong Raman modes of the thiol-capped nanoparticles in aqueous solution have been reported. In the gold nanoparticle systems, gold–citrate binding interactions were observed as well as adsorption of the Raman dyes and binding with the polyethyleneglycol polymer coating and phospholipid coating. These observations coincided with findings from conventional optical techniques. In addition, gold nanoparticles were found to carbonize at high pump power and prolonged exposure time. In summary, the two nanoparticle characterizations demonstrated the high sensitivity and nondestructive nature of the photonic crystal fiber for Raman spectroscopy.