Microwave-assisted synthesis of highly luminescent glutathione-capped Zn1−xCdxTe alloyed quantum dots with excellent biocompatibility

Abstract

In this paper, a microwave-assisted synthesis method has been used to prepare highly luminescent GSH-capped Zn_1−xCd_xTe alloyed quantum dots, with pollutant-free sodium tellurite (Na₂TeO₃) as the Te source. The size and composition-dependent absorption and photoluminescence spectra of the as-prepared alloyed QDs can be tuned from 500 nm to 610 nm, and the photoluminescent quantum yield of our synthesized alloyed QDs can reach up to 90%. The in vitro cytotoxicity studies (MTT-assay) demonstrate that the cytotoxicity of the GSH-capped Zn_1−xCd_xTe alloyed QDs can be reduced to a small extent due to the incorporation of the Zn ions. Green emitting GSH-capped Zn_1−xCd_xTe alloyed QDs are successfully used for A549 cellular imaging on a laser scanning confocal microscopy. Our systematic investigation clearly shows that these high-performance Zn_1−xCd_xTe alloyed QDs are highly promising biological fluorescent labels in biological applications.