• Application of Quantum Dots in Tumor Imaging
  • Fereshteh Alizadeh,1 Sara Daneshjou,2,*
    1. Phd student of Nanobiotechnology, Department of Nanobiotechnology, Faculty of Biological Science, Tarbiat Modares University
    2. Assistant professor of Nanobiotechnology, Faculty of Biological Science, Tarbiat Modares University


  • Introduction: Cancer is one of the most common causes of death worldwide. One of the fundamental steps to ensure optimal cancer treatment is the early detection of cancer cells. Due to the limitations of conventional cancer diagnostic methods, such as the lack of stability of contrast agents, photobleaching and poor spectrum with narrow excitation and broad emission, other strategies, including nanotechnology, have been used to improve diagnosis and reduce the severity of the disease. Nowadays, fluorescent semiconductor nanostructures (quantum dots, QDs) have attracted much attention due to their small size (less than 10 nm), high photostability, high quantum yield, tunable color, broad excitation spectrum, narrow emission spectrum, negligible optical fading, excellent biocompatibility, low toxicity, and chemical inertness. QDs are tiny three-dimensional particles and trap electrons from the conduction band, holes from the valence band and excitons in three spatial directions. Carbon quantum dots (CQDs) and graphene quantum dots (GQDs) are the two most important subgroups of carbon dots (CDs). To image tumors, many researchers have focused on the construction of nanoparticle systems functionalized with ligands that target tumors. By modifying them with specific surface coatings, quantum dots can be used to effectively label tumor cells at both the cellular and subcellular levels. Quantum dots can be conjugated with peptides, antibodies or small molecules and used for the detection of cancer cells and molecular biomarkers.
  • Methods: This review article has been collected from reliable scientific sources and is the result of studying many researches of the authors.
  • Results: The excellent fluorescence intensity and photochemical stability of QDs are justification for their increased applications in tumor imaging, optical sensing, bioimaging, and optical monitoring.
  • Conclusion: The cytotoxicity effect of quantum dots severely limits their in vivo applications. Therefore, the searches for benign alternatives have continued. In addition, synthesizing biocompatible fluorescent agents for early-stage cancer imaging is challenging. Furtheremore tethering the targeting molecules onto the CQDs still remains a great challenge for constructing a perfect “smart” theranostic agent, which is a multiple functional platform integrating imaging, targeting, and therapeutic functions.
  • Keywords: Cancer, Fluorescence Quantum dot, Nanotechnology, Tumor imaging