Spectroscopic and Physical Characterization of Functionalized Au Nanoparticles: A Multiweek Experimental Project

• Autores: Jean-Francois Masson, Hélène Yockell-Lelièvre
• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 91, Nº 10, 2014, págs. 1557-1562
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • A term project was introduced in teaching advanced spectroscopy and notions of nanotechnology to chemistry students at the graduate level (M.Sc. and Ph.D.). This project could also be suited for an honor�s thesis at the undergraduate level. Students were assigned a unique combination of nanoparticle synthesis (13 nm Au nanospheres, ~100 nm nanoraspberries or ~50 nm nanostars) and fluorescent/ Raman-active ligand (HS-PEG-FITC, rhodamine 6G, 4-mercaptobenzoic acid, 4- nitrobenzenethiol, and phenanthroline). Characterization with transmission electron microscopy allowed the students to confirm the shape and size distribution of nanoparticles. The ligands immobilized on the surface of the nanoparticles were extensively characterized using a suite of optical techniques. UV-vis was used to observe the plasmonic bands of particles of varying shapes, and fluorescent spectroscopy was used to construct fluorescent pathways with the aid of Jablonski diagrams. The vibrational bands of the ligands were identified using IR and Raman spectroscopy. Performing surface-enhanced Raman spectroscopy (SERS) on the nanoparticle at different excitation wavelength (488, 633, and 785 nm) was used to understand the influence of the surface plasmon on SERS and fluorescence spectroscopies. Students were required to write a full scientific paper for the report of the term project.