CdTe quantum dots (QDs) were prepared in an aqueous solution using thioglycollic acid as a stabilizing agent. After an appropriate illumination and storage, the photoluminescence (PL) and stability of the CdTe nanoparticles were enhanced. Then the water-soluble and highly stable QDs were used as a photo-catalyzer for the degradation of ethidium bromide (EB). Factors that concern fluorescent CdTe with a photocatalysis reaction including pH and irradiation time were investigated. Absorption of the photocatalysis reaction mixture suggested the decolorization of EB. Effect on the relative fluorescence intensity of EB shows that the rate of degradation can be 90% in water after 4 h under UV irradiation. Moreover, CdTe QDs also worked in agarose gel, in which EB was used as an intercalating fluorescence probe for the recognition of nucleic acids.

Key words: quantum dot, CdTe, ethidium bromide, photo-catalysis, photodegradation of dye