Development of Bimodal Medical Imaging Probe Using Cadmium Zinc Selenium Quantum Dots

Abstract

newline In recent years, a new generation of multifunctional nanoparticles has been proposed for biomedical applications. The aim for the development of these multifuntional nanoparticles is to enable or improve their performance for imaging, diagnostic and therapeutic applications. Semiconductor quantum dots (QDs) are light emitting particles on a nanometer scale that have emerged as a new class of fluorescent labels for chemical analysis, molecular imaging and biomedical diagnostics. This thesis reports the facile synthesis of Cd/ZnSe quantum dots using three different stabilizing agents namely, L-cysteine, thioglycolic acid and cysteamine hydrochloride. The facile synthesized quantum dots were characterized for its optical, microstructural and structural properties along with its band-gap energy calculation and nonlinear optical properties. This thesis further reports the direct immobilization of gadolinium chelate on the cysteamine hydrochloride stabilized Cd/ZnSe quantum dots for utilizing them as bimodal imaging probe (fluorescence and magnetic resonance imaging(MRI)). This developed bimodal imaging probe was tested for its toxicity using hemolysis assay (in vitro), in Danio rerio embryos and in Wistar Albino female rats (in vivo). Conclusively, the imaging probe is tested for its ability to produce signal from an agarose phantom in both imaging modality - fluorescence in vivo small animal imaging system and MRI.