Quantum Dots (QD) are semiconductor nanoparticles possessing unique size dependent optical properties. They are are usually between 2 and 10 nanometers wide (10 and 50 atoms). In a QD (e.g. CdS), the movement of electrons is confined and energy levels are quantized. As the particle gets smaller, its band gap energy increases. This provides a size-dependent band gap which is very instrumental in designing materials with tailored optical properties. QDs are exploited in a variety of fields including solar cells, LEDs, sensors, lasers, medical imaging, and labeling. In the present project, the aim is to sythesize hybrid nanoparticles showing both superparamagnetic and luminescent properties by binding Fe3O4 molecules to CdS molecules. In order to obtain QD properties and superparamagnetism, the size of these hybrid particles will be confined to less than 10 nm. Thus, these particles will be usable as contrast media in magnetic resonance imaging and drug delivery systems used in cancer therapy. TÜBİTAK UME is responsible for the characterization and scientific evaluation of the magnetic properties of these particles.