Controllable synthesis and cell-imaging studies on CdTe quantum dots together capped by glutathione and thioglycolic acid.

This paper describes the synthesis of CdTe quantum dots (QDs) in aqueous solution using two stabilizers (GSH and TGA), which have never been used together but separately. The synthetic procedure is simple and controllable. Different-sized CdTe QDs with controllable photoluminescence (PL) wavelengths from 500 to 610 nm can be synthesized within 5 h in aqueous solutions at a temperature of 100 degrees C. When the molar ratio of GSH to TGA is 1:1, quantum yields (QY) of the yellow-emitting CdTe QD550 (QDs with emission maximum at 550 nm) obtained can reach to 63% without any postpreparation treatment. The synthesized CdTe QDs possess free carboxyl and amino groups, which were successfully conjugated with insulin (INS) for delivery to cells, demonstrating that they can be easily bound bimolecularly and have potentially broad applications as bioprobes.