title: Modification of Structural and Luminescence Properties of Graphene Quantum Dots by Gamma Irradiation and Their Application in a Photodynamic Therapy.
abstract: Herein, the ability of gamma irradiation to enhance the photoluminescence properties of graphene quantum dots (GQDs) was investigated. Different doses of γ-irradiation were used on GQDs to examine the way in which their structure and optical properties can be affected. The photoluminescence quantum yield was increased six times for the GQDs irradiated with high doses compared to the nonirradiated material. Both photoluminescence lifetime and values of optical band gap were increased with the dose of applied gamma irradiation. In addition, the exploitation of the gamma-irradiated GQDs as photosensitizers was examined by monitoring the production of singlet oxygen under UV illumination. The main outcome was that the GQDs irradiated at lower doses act as better photoproducers than the ones irradiated at higher doses. These results corroborate that the structural changes caused by gamma irradiation have a direct impact on GQD ability to produce singlet oxygen and their photostability under prolonged UV illumination. This makes low-dose irradiated GQDs promising candidates for photodynamic therapy.
authors.affiliation: Vinča Institute of Nuclear Sciences, University of Belgrade , P.O. Box 522, Mike Petrovica Alasa 12-14, 11001 Belgrade, Serbia.
authors.forename: Svetlana P
authors.initials: SP
authors.lastname: Jovanović
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, INSTM, Center of Excellence for Nanostructured Materials (CENMAT), University of Trieste , via L. Giorgieri 1, 34127 Trieste, Italy.
authors.forename: Zois
authors.initials: Z
authors.lastname: Syrgiannis
authors.affiliation: Vinča Institute of Nuclear Sciences, University of Belgrade , P.O. Box 522, Mike Petrovica Alasa 12-14, 11001 Belgrade, Serbia.
authors.forename: Zoran M
authors.initials: ZM
authors.lastname: Marković
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, INSTM, Center of Excellence for Nanostructured Materials (CENMAT), University of Trieste , via L. Giorgieri 1, 34127 Trieste, Italy.
authors.forename: Aurelio
authors.initials: A
authors.lastname: Bonasera
authors.affiliation: Vinča Institute of Nuclear Sciences, University of Belgrade , P.O. Box 522, Mike Petrovica Alasa 12-14, 11001 Belgrade, Serbia.
authors.forename: Dejan P
authors.initials: DP
authors.lastname: Kepić
authors.affiliation: Vinča Institute of Nuclear Sciences, University of Belgrade , P.O. Box 522, Mike Petrovica Alasa 12-14, 11001 Belgrade, Serbia.
authors.forename: Milica D
authors.initials: MD
authors.lastname: Budimir
authors.affiliation: Vinča Institute of Nuclear Sciences, University of Belgrade , P.O. Box 522, Mike Petrovica Alasa 12-14, 11001 Belgrade, Serbia.
authors.forename: Dušan D
authors.initials: DD
authors.lastname: Milivojević
authors.affiliation: Vinča Institute of Nuclear Sciences, University of Belgrade , P.O. Box 522, Mike Petrovica Alasa 12-14, 11001 Belgrade, Serbia.
authors.forename: Vuk D
authors.initials: VD
authors.lastname: Spasojević
authors.affiliation: Vinča Institute of Nuclear Sciences, University of Belgrade , P.O. Box 522, Mike Petrovica Alasa 12-14, 11001 Belgrade, Serbia.
authors.forename: Miroslav D
authors.initials: MD
authors.lastname: Dramićanin
authors.affiliation: Faculty of Agriculture, University of Belgrade , P.O. Box 127, Nemanjina 6, 11080 Zemun, Serbia.
authors.forename: Vladimir B
authors.initials: VB
authors.lastname: Pavlović
authors.affiliation: Vinča Institute of Nuclear Sciences, University of Belgrade , P.O. Box 522, Mike Petrovica Alasa 12-14, 11001 Belgrade, Serbia.
authors.forename: Biljana M
authors.initials: BM
authors.lastname: Todorović Marković
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D005720:Gamma Rays; D006108:Graphite / Q000737:chemistry*; D049449:Luminescence; D018625:Microscopy, Atomic Force; D010316:Particle Size; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000494:pharmacology; D045663:Quantum Dots / Q000737:chemistry*; D026082:Singlet Oxygen / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D017319:Photosensitizing Agents; D026082:Singlet Oxygen; D006108:Graphite
keywords: gamma irradiation; graphene quantum dots; photodynamic therapy; photoluminescence; quantum yield