The multidisciplinary work in this thesis, which ranges from the synthesis and characterization of CdSe/CdS core-shell quantum dots to the determination of their potential as intracellular biomarkers, results from the ongoing collaboration between the Physics and Chemistry of Nanostructures (PCN) group and the Bio-Photonic Imaging (BPI) group. The research activities in the PCN group focuses on semiconductor nanocrystals and other nanoparticles, and has therefore developed a strong expertise in the synthesis and characterization techniques of colloidal materials. The research in the BPI group is aimed at the development and application of biophotonic methods for biomedical diagnostics, drug delivery and therapy. These two research groups are thus ideal partners towards achieving biocompatible CdSe/CdS@SiO2 nanoparticles for intracellular labeling.