Graphene quantum dots as singlet oxygen producer or radical quencher - The matter of functionalization with urea/thiourea.

Journal: Materials science & engineering. C, Materials for biological applications
PMID: 32229000

Abstract

Due to their low cost and possible green synthesis, high stability and resistance to photobleaching, graphene quantum dots (GQDs) can be considered as one of the class of carbon nanomaterials which may have great potential as an agent for photosensitized oxygen activation. In such a way, GQDs can be used as a theranostic agent in photodynamic therapy. In this work pristine GQDs, GQDs irradiated with gamma rays and GQDs doped with N and N, S atoms are produced using a simple, green approach. By using different techniques (AFM, HR-TEM, SEM-EDS, FTIR, XRD, PL and UV-Vis) we investigated structural and optical properties of the new types of GQDs. We showed that GQDs functionalized with thiourea (GQDs-TU) completely lost the ability to produce singlet oxygen (O) upon photoexcitation while functionalization with urea (GQDs-U) improves the capability of GQDs to produce O upon the same conditions. Thus, presented GQDs modification with urea seems like a promising approach for the production of the efficient photosensitizer. On the opposite, GQDs-TU are efficient OH quencher. Due to high singlet oxygen production and low cytotoxicity below 100 μg/mL against HeLa cells, GQDs-U is a good candidate as an agent in photodynamic therapy at this concentration.

Authors

  • Svetlana P Jovanović
    Vinča Institute of Nuclear Sciences, University of Belgrade, P. O. Box 522, 11001 Belgrade, Serbia. Electronic address: svetlanajovanovic@vinca.rs.
  • Zois Syrgiannis
    Center of Excellence for Nanostructured Materials (CENMAT) and INSTM, Unit of Trieste, Department of Chemical and Pharmaceutical Sciences, University of Trieste, Trieste, Italy.
  • Milica D Budimir
    Vinča Institute of Nuclear Sciences, University of Belgrade, P. O. Box 522, 11001 Belgrade, Serbia.
  • Dusan D Milivojević
    Vinča Institute of Nuclear Sciences, University of Belgrade, P. O. Box 522, 11001 Belgrade, Serbia.
  • Dragana J Jovanovic
    Vinča Institute of Nuclear Sciences, University of Belgrade, P. O. Box 522, 11001 Belgrade, Serbia.
  • Vladimir B Pavlović
    Faculty of Agriculture, University of Belgrade, P. O. Box 14, 11081 Belgrade-Zemun, Serbia.
  • Jelena M Papan
    Vinča Institute of Nuclear Sciences, University of Belgrade, P. O. Box 522, 11001 Belgrade, Serbia.
  • Malte Bartenwerfer
    Department of Computing Science, Division Microrobotics and Control Engineering, Univerzitet Carl von Ossietzky, D-26129 Oldenburg, Germany.
  • Marija M Mojsin
    Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, P.O. Box 23, 11010 Belgrade, Serbia.
  • Milena J Stevanović
    Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, P.O. Box 23, 11010 Belgrade, Serbia; Faculty of Biology, University of Belgrade, Studentskitrg 16, 11000 Belgrade, Serbia; Serbian Academy of Sciences and Arts, KnezMihailova 35, 11000 Belgrade, Serbia.
  • Biljana M Todorović Marković
    Vinča Institute of Nuclear Sciences, University of Belgrade, P. O. Box 522, 11001 Belgrade, Serbia.

Keywords

External Resources

Popular Topics
Recent Journals