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Characterization of QD in-vivo in a rat model
Author
Loh, Gaik Juen
Supervisor
Kwek, Leong Chuan
Abstract
Quantum dots are tiny light-emitting semiconductor particles on the nanometer scale. They are emerging as a new class of biomarker with properties and applications that are superior to conventional organic dyes and fluorescent proteins. In this study, we focus on modified ZnO quantum dots. Non-Cd based QDs become increasingly important in bioimaging as it has lower cytotoxicity which is an important issue when in-vivo imaging
is concerned. Besides low toxicity, ZnO is less sensitive to environmental changes such as thermal, chemical and photochemical disturbances. The procedure and chemistry of the synthesis and surface modifications of four ZnO based QDs were discussed. Three dopants (Cu, CO and Ni) and three capping agents (260, 261 and TiOz) were used to create the four modified ZnO quantum dots. The lifetime and fluorescence spectrum of the four modified ZnO quantum dots colloidal solutions were evaluated. All four QDs showed bioimaging capability on plant cells with ZnO doped with Cu and CO and capped with Z60 showed the best result. These two modified ZnO were diluted into two concentrations (50pM and 100pM), suitable for use in vivo in rats. Fluorescence spectra of four rat organs, namely the liver, kidney, lung and spleen were measured in vivo by the use of a laser probe spectrofluorometer. The Cu and CO doped ZnO showed positive results in these spectra in different time frame; CO doped ZnO showed fluorescence emission just after 1 hour of QD injection into rat while Cu doped ZnO showed fluorescence emission only after 24 hours after it was injected into rat. The tissue of the four organs were sectioned and imaged under confocal laser scanning microscopy and some cells unique to each organ had been identified. From this study, we can conclude that it is feasible to use ZnO QDs in vivo in rats and future work can be laid out and conducted for deeper understanding.
Date Issued
2009
Call Number
QH324.9.B48 Loh
Date Submitted
2009