TY  - JOUR
AU  - Jovanović, Svetlana P.
AU  - Syrgiannis, Zois
AU  - Budimir, Milica D.
AU  - Milivojević, Dušan D.
AU  - Jovanović, Dragana J.
AU  - Pavlović, Vladimir
AU  - Papan, Jelena M.
AU  - Bartenwerfer, Malte
AU  - Mojsin, Marija M.
AU  - Stevanović, Milena J.
AU  - Todorović-Marković, Biljana
PY  - 2020
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/5390
AB  - 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, HRTEM, 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-1(2)) upon photoexcitation while functionalization with urea (GQDs-U) improves the capability of GQDs to produce O-1(2) 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 mu g/mL against HeLa cells, GQDs-U is a good candidate as an agent in photodynamic therapy at this concentration.
PB  - Elsevier, Amsterdam
T2  - Materials Science & Engineering C-Materials for Biological Applications
T1  - Graphene quantum dots as singlet oxygen producer or radical quencher The matter of functionalization with urea/thiourea
VL  - 109
DO  - 10.1016/j.msec.2019.110539
ER  - 

@article{
author = "Jovanović, Svetlana P. and Syrgiannis, Zois and Budimir, Milica D. and Milivojević, Dušan D. and Jovanović, Dragana J. and Pavlović, Vladimir and Papan, Jelena M. and Bartenwerfer, Malte and Mojsin, Marija M. and Stevanović, Milena J. and Todorović-Marković, Biljana",
year = "2020",
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, HRTEM, 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-1(2)) upon photoexcitation while functionalization with urea (GQDs-U) improves the capability of GQDs to produce O-1(2) 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 mu g/mL against HeLa cells, GQDs-U is a good candidate as an agent in photodynamic therapy at this concentration.",
publisher = "Elsevier, Amsterdam",
journal = "Materials Science & Engineering C-Materials for Biological Applications",
title = "Graphene quantum dots as singlet oxygen producer or radical quencher The matter of functionalization with urea/thiourea",
volume = "109",
doi = "10.1016/j.msec.2019.110539"
}

Jovanović, S. P., Syrgiannis, Z., Budimir, M. D., Milivojević, D. D., Jovanović, D. J., Pavlović, V., Papan, J. M., Bartenwerfer, M., Mojsin, M. M., Stevanović, M. J.,& Todorović-Marković, B.. (2020). Graphene quantum dots as singlet oxygen producer or radical quencher The matter of functionalization with urea/thiourea. in Materials Science & Engineering C-Materials for Biological Applications
Elsevier, Amsterdam., 109.
https://doi.org/10.1016/j.msec.2019.110539

Jovanović SP, Syrgiannis Z, Budimir MD, Milivojević DD, Jovanović DJ, Pavlović V, Papan JM, Bartenwerfer M, Mojsin MM, Stevanović MJ, Todorović-Marković B. Graphene quantum dots as singlet oxygen producer or radical quencher The matter of functionalization with urea/thiourea. in Materials Science & Engineering C-Materials for Biological Applications. 2020;109.
doi:10.1016/j.msec.2019.110539 .

Jovanović, Svetlana P., Syrgiannis, Zois, Budimir, Milica D., Milivojević, Dušan D., Jovanović, Dragana J., Pavlović, Vladimir, Papan, Jelena M., Bartenwerfer, Malte, Mojsin, Marija M., Stevanović, Milena J., Todorović-Marković, Biljana, "Graphene quantum dots as singlet oxygen producer or radical quencher The matter of functionalization with urea/thiourea" in Materials Science & Engineering C-Materials for Biological Applications, 109 (2020),
https://doi.org/10.1016/j.msec.2019.110539 . .

TY  - JOUR
AU  - Jovanović, Svetlana P.
AU  - Syrgiannis, Zois
AU  - Marković, Zoran M.
AU  - Bonasera, Aurelio
AU  - Kepić, Dejan P.
AU  - Budimir, Milica D.
AU  - Milivojević, Dušan D.
AU  - Spasojević, Vuk D.
AU  - Dramicanin, Miroslav D.
AU  - Pavlović, Vladimir
AU  - Todorović-Marković, Biljana
PY  - 2015
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/3755
AB  - Herein, the ability of gamma irradiation to enhance the photoluminescence properties of graphene quantum dots (GQDs) was investigated. Different doses of gamma-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.
PB  - Amer Chemical Soc, Washington
T2  - ACS Applied Materials & Interfaces
T1  - Modification of Structural and Luminescence Properties of Graphene Quantum Dots by Gamma Irradiation and Their Application in a Photodynamic Therapy
EP  - 25874
IS  - 46
SP  - 25865
VL  - 7
DO  - 10.1021/acsami.5b08226
ER  - 

@article{
author = "Jovanović, Svetlana P. and Syrgiannis, Zois and Marković, Zoran M. and Bonasera, Aurelio and Kepić, Dejan P. and Budimir, Milica D. and Milivojević, Dušan D. and Spasojević, Vuk D. and Dramicanin, Miroslav D. and Pavlović, Vladimir and Todorović-Marković, Biljana",
year = "2015",
abstract = "Herein, the ability of gamma irradiation to enhance the photoluminescence properties of graphene quantum dots (GQDs) was investigated. Different doses of gamma-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.",
publisher = "Amer Chemical Soc, Washington",
journal = "ACS Applied Materials & Interfaces",
title = "Modification of Structural and Luminescence Properties of Graphene Quantum Dots by Gamma Irradiation and Their Application in a Photodynamic Therapy",
pages = "25874-25865",
number = "46",
volume = "7",
doi = "10.1021/acsami.5b08226"
}

Jovanović, S. P., Syrgiannis, Z., Marković, Z. M., Bonasera, A., Kepić, D. P., Budimir, M. D., Milivojević, D. D., Spasojević, V. D., Dramicanin, M. D., Pavlović, V.,& Todorović-Marković, B.. (2015). Modification of Structural and Luminescence Properties of Graphene Quantum Dots by Gamma Irradiation and Their Application in a Photodynamic Therapy. in ACS Applied Materials & Interfaces
Amer Chemical Soc, Washington., 7(46), 25865-25874.
https://doi.org/10.1021/acsami.5b08226

Jovanović SP, Syrgiannis Z, Marković ZM, Bonasera A, Kepić DP, Budimir MD, Milivojević DD, Spasojević VD, Dramicanin MD, Pavlović V, Todorović-Marković B. Modification of Structural and Luminescence Properties of Graphene Quantum Dots by Gamma Irradiation and Their Application in a Photodynamic Therapy. in ACS Applied Materials & Interfaces. 2015;7(46):25865-25874.
doi:10.1021/acsami.5b08226 .

Jovanović, Svetlana P., Syrgiannis, Zois, Marković, Zoran M., Bonasera, Aurelio, Kepić, Dejan P., Budimir, Milica D., Milivojević, Dušan D., Spasojević, Vuk D., Dramicanin, Miroslav D., Pavlović, Vladimir, Todorović-Marković, Biljana, "Modification of Structural and Luminescence Properties of Graphene Quantum Dots by Gamma Irradiation and Their Application in a Photodynamic Therapy" in ACS Applied Materials & Interfaces, 7, no. 46 (2015):25865-25874,
https://doi.org/10.1021/acsami.5b08226 . .

TY  - JOUR
AU  - Prekodravac, Jovana
AU  - Marković, Zoran
AU  - Jovanović, Svetlana P.
AU  - Budimir, Milica D.
AU  - Perusko, Davor
AU  - Holclajtner-Antunović, Ivanka
AU  - Pavlović, Vladimir
AU  - Syrgiannis, Zois
AU  - Bonasera, Aurelio
AU  - Todorović-Marković, Biljana
PY  - 2015
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/3685
AB  - In this paper, we performed synthesis of graphene thin films by rapid thermal annealing (RTA) of thin nickel copper (Ni/Cu) layers deposited on spectroscopic graphite as a carbon source. Furthermore, we investigated the effect of annealing temperature and annealing time on formation and quality of synthesized graphene films. Raman spectroscopy study showed that annealing at lower temperatures results in formation of monolayer graphene films, while annealing at higher temperatures results in formation of multilayer graphene films. We used Raman mapping to determine the distribution of graphene sheets. Surface morphology of graphene thin films was investigated by atomic force microscopy and scanning electron microscopy with EDS probe.
PB  - Elsevier Science Sa, Lausanne
T2  - Synthetic Metals
T1  - The effect of annealing temperature and time on synthesis of graphene thin films by rapid thermal annealing
EP  - 467
SP  - 461
VL  - 209
DO  - 10.1016/j.synthmet.2015.08.015
ER  - 

@article{
author = "Prekodravac, Jovana and Marković, Zoran and Jovanović, Svetlana P. and Budimir, Milica D. and Perusko, Davor and Holclajtner-Antunović, Ivanka and Pavlović, Vladimir and Syrgiannis, Zois and Bonasera, Aurelio and Todorović-Marković, Biljana",
year = "2015",
abstract = "In this paper, we performed synthesis of graphene thin films by rapid thermal annealing (RTA) of thin nickel copper (Ni/Cu) layers deposited on spectroscopic graphite as a carbon source. Furthermore, we investigated the effect of annealing temperature and annealing time on formation and quality of synthesized graphene films. Raman spectroscopy study showed that annealing at lower temperatures results in formation of monolayer graphene films, while annealing at higher temperatures results in formation of multilayer graphene films. We used Raman mapping to determine the distribution of graphene sheets. Surface morphology of graphene thin films was investigated by atomic force microscopy and scanning electron microscopy with EDS probe.",
publisher = "Elsevier Science Sa, Lausanne",
journal = "Synthetic Metals",
title = "The effect of annealing temperature and time on synthesis of graphene thin films by rapid thermal annealing",
pages = "467-461",
volume = "209",
doi = "10.1016/j.synthmet.2015.08.015"
}

Prekodravac, J., Marković, Z., Jovanović, S. P., Budimir, M. D., Perusko, D., Holclajtner-Antunović, I., Pavlović, V., Syrgiannis, Z., Bonasera, A.,& Todorović-Marković, B.. (2015). The effect of annealing temperature and time on synthesis of graphene thin films by rapid thermal annealing. in Synthetic Metals
Elsevier Science Sa, Lausanne., 209, 461-467.
https://doi.org/10.1016/j.synthmet.2015.08.015

Prekodravac J, Marković Z, Jovanović SP, Budimir MD, Perusko D, Holclajtner-Antunović I, Pavlović V, Syrgiannis Z, Bonasera A, Todorović-Marković B. The effect of annealing temperature and time on synthesis of graphene thin films by rapid thermal annealing. in Synthetic Metals. 2015;209:461-467.
doi:10.1016/j.synthmet.2015.08.015 .

Prekodravac, Jovana, Marković, Zoran, Jovanović, Svetlana P., Budimir, Milica D., Perusko, Davor, Holclajtner-Antunović, Ivanka, Pavlović, Vladimir, Syrgiannis, Zois, Bonasera, Aurelio, Todorović-Marković, Biljana, "The effect of annealing temperature and time on synthesis of graphene thin films by rapid thermal annealing" in Synthetic Metals, 209 (2015):461-467,
https://doi.org/10.1016/j.synthmet.2015.08.015 . .