CdTe Quantum Dot/Dye Hybrid System as Photosensitizer for Photodynamic Therapy

Abstract

We have studied the photodynamic properties of novel CdTe quantum dots?methylene blue hybrid photosensitizer. Absorption spectroscopy, photolumines- cence spectroscopy, and fluorescence lifetime imaging of this system reveal efficient charge transfer between nano- crystals and the methylene blue dye. Near-infrared photo- luminescence measurements provide evidence for an increased efficiency of singlet oxygen production by the methylene blue dye. In vitro studies on the growth of HepG2 and HeLa cancerous cells were also performed, they point toward an improvement in the cell kill efficiency for the methylene blue-semiconductor nanocrystals hybrid system.