One-step fabrication of biocompatible chitosan-coated ZnS and ZnS:Mn(2+ )quantum dots via a γ-radiation route

Biocompatible chitosan-coated ZnS quantum dots [CS-ZnS QDs] and chitosan-coated ZnS:Mn(2+ )quantum dots [CS-ZnS:Mn(2+ )QDs] were successfully fabricated via a convenient one-step γ-radiation route. The as-obtained QDs were around 5 nm in diameter with excellent water-solubility. These QDs emitting strong visible blue or orange light under UV excitation were successfully used as labels for PANC-1 cells. The cell experiments revealed that CS-ZnS and CS-ZnS:Mn(2+ )QDs showed low cytotoxicity and good biocompatibility, which offered possibilities for further biomedical applications. Moreover, this convenient synthesis strategy could be extended to fabricate other nanoparticles coated with chitosan. PACS: 81.07.Ta; 78.67.Hc; 82.35.Np; 87.85.Rs.