Development of Semiconductor Nanocrystals for Biotechnological Applications

Abstract

Semiconductor nanocrystals are very useful tools in biological applications because of their unique optical properties. In this study, synthesis and characterization of CdTe / CdS and CdSexS1-x nanocrystals were carried out. CdSexS1-x nanocrystals were synthesized by a modified two phase method. Highly luminescent (Quantum yied . %80) , monodisperse and face centered cubic CdSexS1-x nanocrystals were obtained in toluene. The size of nanoparticles varies from 3.5 to 3.7 nm Ligand exchange was performed on CdSexS1-x nanocrystals and luminescent water soluble CdSexS1-x nanocrystals were obtained. CdTe / CdS nanocrystals were synthesized in one step and and one pot by a modified method. Face centered cubic, luminescent (Quantum yield . 30%) and monodisperse CdTe / CdS nanocrystals with different sizes in a size range from 4.7 to 9.3 nm were obtained in water. Toxicity of CdTe / CdS nanocrystals was determined by MTT test. The lethal concentrations were respectively 1.0 and 15 .g/ml for PC3 and MCF7 cells. Confocal microscopy shows that the nanoparticles enter to the cytoplasm of cells.