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Journal of Nanomaterials
Volume 2013 (2013), Article ID 291020, 8 pages
Research Article

Enhanced Intracellular Uptake of CdTe Quantum Dots by Conjugation of Oligopeptides

1Department of Polymer Science and Engineering, Kyungpook National University, Daegu 702-701, Republic of Korea
2Department of Diagnostic Radiology, Kyungpook National University, Daegu 702-701, Republic of Korea
3College of Chemistry and Molecular Engineering, Peking University, Beijing 100-871, China

Received 10 January 2013; Accepted 3 April 2013

Academic Editor: Miguel A. Correa-Duarte

Copyright © 2013 Moon-Jeong Choi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Arg-Gly-Asp-Ser (RGDS), a typical membrane-permeable carrier peptide, was conjugated with mercaptoisobutyric acid-immobilized CdTe quantum dot (CTNPs) to enhance the intracellular uptake of quantum dots. Mean size of mercaptoisobutyric acid-immobilized quantum dots (37 nm) as determined by dynamic light scattering was increased up to 54 nm after RGDS immobilization. It was found, from in vitro cell culture experiment, that fibroblast (NIH 3T3) cells were well proliferated in the presence of RGDS-conjugated quantum dots (RCTNPs), and the intracellular uptake of CTNPs and RCTNPs was studied by means of ICP and fluorescence microscopy. As a result, the RCTNPs specifically bound to the membrane of NIH 3T3 cells and almost saturated after 6 hours incubation. The amount of RCTNPs uptaken by the cells was higher than that of CTNPs, demonstrating the enhancing effect of RGDS peptide conjugation on the intracellular uptake of quantum dots (QDs).