- Title
- Photophysical properties of zinc carboxy phthalocyanine-quantum dot conjugates
- Title
- Photophysical properties of zinc carboxy phthalocyanines-quantum dot conjugates
- Creator
- Sekhosana, Kutloano Edward
- ThesisAdvisor
- Nyokong, Tebello
- ThesisAdvisor
- Litwinski, Christian
- Subject
- Phthalocyanines
- Subject
- Quantum dots
- Subject
- Zinc
- Subject
- Photochemistry
- Subject
- Atomic force microscopy
- Subject
- Transmission electron microscopy
- Subject
- Raman spectroscopy
- Subject
- Infrared spectroscopy
- Subject
- X-ray photoelectron spectroscopy
- Date
- 2013
- Date
- 2013-03-27
- Type
- Thesis
- Type
- Masters
- Type
- MSc
- Identifier
- vital:4276
- Identifier
- http://hdl.handle.net/10962/d1001652
- Identifier
- Phthalocyanines
- Identifier
- Quantum dots
- Identifier
- Zinc
- Identifier
- Photochemistry
- Identifier
- Atomic force microscopy
- Identifier
- Transmission electron microscopy
- Identifier
- Raman spectroscopy
- Identifier
- Infrared spectroscopy
- Identifier
- X-ray photoelectron spectroscopy
- Description
- This thesis presents work based on the interactions of water soluble caboxylated zinc phthalocyanines (Pcs) and coreshell quantum dots (QDs). The Pcs are ZnPc(COOH)₈ and ZnPc(COOH)₄ and coreshell QDs are CdTe@ZnS-GSH. GSH = L-glutathione. Characterization and photophysical studies of conjugates were carried out. The approach of coordinating Pcs to QDs was achieved using an organic cross linker, N-N’-dicyclohexylcarbodiimide (DCC) at pH 10 at room temperature. Employing atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman, infrared and X-ray photoelectron spectroscopies, the formation of the conjugates was confirmed. Upon conjugation with Pc derivatives, the fluorescence quantum yield of CdTe@ZnS-GSH decreased due to energy transfer from the QDs to the Pc. The average fluorescence lifetime of the CdTe@ZnS-GSH QD also decreased upon conjugation. The föster resonance energy transfer (FRET) behaviour of CdTe@ZnS-GSH-ZnPc(COOH)₄ conjugates was compared to that of CdTe@ZnS-GSH-ZnPc(COOH)₈. Higher FRET efficiencies were observed for CdTe@ZnS-GSH-ZnPc(COOH)₄-mixed or CdTe@ZnS-GSH-ZnPc(COOH)₄-linked compared to the corresponding CdTe@ZnS-GSH-ZnPc(COOH)₈-mixed or CdTe@ZnS-GSH-ZnPc(COOH)₈-linked. Triplet quantum yield (ΦT) and lifetime (ΤT) of ZnPc(COOH)₈ were found to increase in the presence of coreshell QDs. Though the singlet quantum yield (ΦΔ) value of ZnPc(COOH)8 was lower than ΦT , there was a slight upsurge in the ΦT in the presence of QDs.
- Description
- Microsoft� Word 2010
- Description
- Adobe Acrobat 9.53 Paper Capture Plug-in
- Format
- 114 p., pdf
- Publisher
- Rhodes University, Faculty of Science, Chemistry
- Language
- English
- Rights
- Sekhosana, Kutloano Edward
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