In this research, the use of gold nanostructures (AuNS) was explored to evaluate the interaction between molecules and the nanoparticle (NP) surface. In that way, three different projects were developed; one project using fluorescence and two projects using Raman spectroscopy as measuring technique.
The fluorescence spectroscopy project used the fluorescence lifetime imaging microscope (FLIM) to evaluate the relative position of the molecules methylene blue (MB) and cucurbit[7]uril (CB) on the gold nanoparticle (AuNP) surface. Although the inclusion complex is favored in solution, it was found that MB forms an exclusion complex with CB, when CB is attached to the AuNP surface.
The first project utilizing Raman spectroscopy, specifically surface enhanced Raman scattering (SERS), took advantage of a confined system (a reverse micelle) to evaluate the Raman signal of water molecules in close proximity to the AuNP surface. It was observed that the SERS water signal had a big shift to higher energies compared with the Raman signal of the bulk water; indicating the water molecules in the system are subjected to different bond-stretching energies.
The second Raman project studied the modification of two different AuNS (specifically AuNP and gold nanorod -AuNR) with thiols. Different thiols were used to evaluate the kinetics of the modification of the AuNS surface, also the different AuNS presented different ligands on their surface. In general, and considering the difference in the bonding strength of the ligands present on the AuNS surface (by synthesis) and the size of the thiol, at least 2 h are required to modify the complete AuNS surface.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/37950 |
| Date | 01 August 2018 |
| Creators | Rondon B., Rebeca A. |
| Contributors | Scainao, Juan |
| Publisher | Université d'Ottawa / University of Ottawa |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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