TY  - JOUR
AU  - Milenković, Mila
AU  - Misović, Aleksandra
AU  - Jovanović, Dragana
AU  - Popović Bijelić, Ana
AU  - Ciasca, Gabriele
AU  - Romano, Sabrina
AU  - Bonasera, Aurelio
AU  - Mojsin, Marija
AU  - Pejić, Jelena
AU  - Stevanović, Milena
AU  - Jovanović, Svetlana
PY  - 2021
UR  - https://imagine.imgge.bg.ac.rs/handle/123456789/1457
AB  - Nowadays, a larger number of aggressive and corrosive chemical reagents as well as toxic solvents are used to achieve structural modification and cleaning of the final products. These lead to the production of residual, waste chemicals, which are often reactive, cancerogenic, and toxic to the environment. This study shows a new approach to the modification of graphene quantum dots (GQDs) using gamma irradiation where the usage of reagents was avoided. We achieved the incorporation of S and N atoms in the GQD structure by selecting an aqueous solution of L-cysteine as an irradiation medium. GQDs were exposed to gamma-irradiation at doses of 25, 50 and 200 kGy. After irradiation, the optical, structural, and morphological properties, as well as the possibility of their use as an agent in bioimaging and photodynamic therapy, were studied. We measured an enhanced quantum yield of photoluminescence with the highest dose of 25 kGy (21.60%). Both S- and N-functional groups were detected in all gamma-irradiated GQDs: amino, amide, thiol, and thione. Spin trap electron paramagnetic resonance showed that GQDs irradiated with 25 kGy can generate singlet oxygen upon illumination. Bioimaging on HeLa cells showed the best visibility for cells treated with GQDs irradiated with 25 kGy, while cytotoxicity was not detected after treatment of HeLa cells with gamma-irradiated GQDs.
PB  - MDPI, Basel
T2  - Nanomaterials
T1  - Facile Synthesis of L-Cysteine Functionalized Graphene Quantum Dots as a Bioimaging and Photosensitive Agent
IS  - 8
SP  - 1879
VL  - 11
DO  - 10.3390/nano11081879
ER  - 

@article{
author = "Milenković, Mila and Misović, Aleksandra and Jovanović, Dragana and Popović Bijelić, Ana and Ciasca, Gabriele and Romano, Sabrina and Bonasera, Aurelio and Mojsin, Marija and Pejić, Jelena and Stevanović, Milena and Jovanović, Svetlana",
year = "2021",
abstract = "Nowadays, a larger number of aggressive and corrosive chemical reagents as well as toxic solvents are used to achieve structural modification and cleaning of the final products. These lead to the production of residual, waste chemicals, which are often reactive, cancerogenic, and toxic to the environment. This study shows a new approach to the modification of graphene quantum dots (GQDs) using gamma irradiation where the usage of reagents was avoided. We achieved the incorporation of S and N atoms in the GQD structure by selecting an aqueous solution of L-cysteine as an irradiation medium. GQDs were exposed to gamma-irradiation at doses of 25, 50 and 200 kGy. After irradiation, the optical, structural, and morphological properties, as well as the possibility of their use as an agent in bioimaging and photodynamic therapy, were studied. We measured an enhanced quantum yield of photoluminescence with the highest dose of 25 kGy (21.60%). Both S- and N-functional groups were detected in all gamma-irradiated GQDs: amino, amide, thiol, and thione. Spin trap electron paramagnetic resonance showed that GQDs irradiated with 25 kGy can generate singlet oxygen upon illumination. Bioimaging on HeLa cells showed the best visibility for cells treated with GQDs irradiated with 25 kGy, while cytotoxicity was not detected after treatment of HeLa cells with gamma-irradiated GQDs.",
publisher = "MDPI, Basel",
journal = "Nanomaterials",
title = "Facile Synthesis of L-Cysteine Functionalized Graphene Quantum Dots as a Bioimaging and Photosensitive Agent",
number = "8",
pages = "1879",
volume = "11",
doi = "10.3390/nano11081879"
}

Milenković, M., Misović, A., Jovanović, D., Popović Bijelić, A., Ciasca, G., Romano, S., Bonasera, A., Mojsin, M., Pejić, J., Stevanović, M.,& Jovanović, S.. (2021). Facile Synthesis of L-Cysteine Functionalized Graphene Quantum Dots as a Bioimaging and Photosensitive Agent. in Nanomaterials
MDPI, Basel., 11(8), 1879.
https://doi.org/10.3390/nano11081879

Milenković M, Misović A, Jovanović D, Popović Bijelić A, Ciasca G, Romano S, Bonasera A, Mojsin M, Pejić J, Stevanović M, Jovanović S. Facile Synthesis of L-Cysteine Functionalized Graphene Quantum Dots as a Bioimaging and Photosensitive Agent. in Nanomaterials. 2021;11(8):1879.
doi:10.3390/nano11081879 .

Milenković, Mila, Misović, Aleksandra, Jovanović, Dragana, Popović Bijelić, Ana, Ciasca, Gabriele, Romano, Sabrina, Bonasera, Aurelio, Mojsin, Marija, Pejić, Jelena, Stevanović, Milena, Jovanović, Svetlana, "Facile Synthesis of L-Cysteine Functionalized Graphene Quantum Dots as a Bioimaging and Photosensitive Agent" in Nanomaterials, 11, no. 8 (2021):1879,
https://doi.org/10.3390/nano11081879 . .

TY  - JOUR
AU  - Jovanović, Svetlana P.
AU  - Syrgiannis, Zois
AU  - Budimir, Milica D.
AU  - Milivojević, Dusan D.
AU  - Jovanović, Dragana J.
AU  - Pavlović, Vladimir B.
AU  - Papan, Jelena M.
AU  - Bartenwerfer, Malte
AU  - Mojsin, Marija
AU  - Stevanović, Milena
AU  - Marković, Biljana M. Todorovic
PY  - 2020
UR  - https://imagine.imgge.bg.ac.rs/handle/123456789/1380
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, Dusan D. and Jovanović, Dragana J. and Pavlović, Vladimir B. and Papan, Jelena M. and Bartenwerfer, Malte and Mojsin, Marija and Stevanović, Milena and Marković, Biljana M. Todorovic",
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. B., Papan, J. M., Bartenwerfer, M., Mojsin, M., Stevanović, M.,& Marković, B. M. T.. (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 VB, Papan JM, Bartenwerfer M, Mojsin M, Stevanović M, Marković BMT. 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, Dusan D., Jovanović, Dragana J., Pavlović, Vladimir B., Papan, Jelena M., Bartenwerfer, Malte, Mojsin, Marija, Stevanović, Milena, Marković, Biljana M. Todorovic, "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  - Marković, Zoran M.
AU  - Jovanović, Svetlana P.
AU  - Masković, Pavle Z.
AU  - Mojsin, Marija
AU  - Stevanović, Milena
AU  - Danko, Martin
AU  - Micusik, Matej
AU  - Jovanović, Dragana J.
AU  - Kleinova, Angela
AU  - Spitalsky, Zdeno
AU  - Pavlović, Vladimir B.
AU  - Marković, Biljana M. Todorovic
PY  - 2019
UR  - https://imagine.imgge.bg.ac.rs/handle/123456789/1221
AB  - Photoactive materials called photosensitizers can be used for treatment of different types of cancer in combination with light source. In this paper, we have investigated pro-oxidant and antioxidant potentials of four graphene based nanomaterials (graphene oxide-GO, graphene quantum dots-GQDs, carbon quantum dots-CQDs and N-doped carbon quantum dots-N-CQDs) depending on the presence/absence of visible light source. Structural and optical properties of these materials and their potentials for reactive oxygen species generation/quenching are investigated by applying different microscopy and spectroscopy techniques (transmission electron microscopy, FTIR, UV-Vis, photoluminescence, electron paramagnetic resonance). Results show that all types of quantum dots has pro-oxidant and antioxidant potentials whereas GO demonstrated only moderate antioxidant effect. The best free radical scavenger is CQDs sample in the absence of light. CQDs are the best singlet oxygen generator under blue light irradiation as well. To check photo-cytotoxicity of these materials, photo-cytotoxic concentrations of the GO, GQDs, CQDs and N-CQDs were determined for three cellular lines: human rhabdomyosarcoma (RD), cell line derived from human cervix carcinoma Hep2c (HeLa) and fibroblast cell line from murine (L2OB). Cytotoxicity test has indicated that all samples are much less photocytotoxic than cis-diamminedichloroplatinum (cis-DPP). The production method and doping of quantum dots affect the photodynamic activity of tested samples very much.
PB  - Elsevier Science Sa, Lausanne
T2  - Journal of Photochemistry and Photobiology B-Biology
T1  - Graphene oxide size and structure pro-oxidant and antioxidant activity and photoinduced cytotoxicity relation on three cancer cell lines
VL  - 200
DO  - 10.1016/j.jphotobiol.2019.111647
ER  - 

@article{
author = "Marković, Zoran M. and Jovanović, Svetlana P. and Masković, Pavle Z. and Mojsin, Marija and Stevanović, Milena and Danko, Martin and Micusik, Matej and Jovanović, Dragana J. and Kleinova, Angela and Spitalsky, Zdeno and Pavlović, Vladimir B. and Marković, Biljana M. Todorovic",
year = "2019",
abstract = "Photoactive materials called photosensitizers can be used for treatment of different types of cancer in combination with light source. In this paper, we have investigated pro-oxidant and antioxidant potentials of four graphene based nanomaterials (graphene oxide-GO, graphene quantum dots-GQDs, carbon quantum dots-CQDs and N-doped carbon quantum dots-N-CQDs) depending on the presence/absence of visible light source. Structural and optical properties of these materials and their potentials for reactive oxygen species generation/quenching are investigated by applying different microscopy and spectroscopy techniques (transmission electron microscopy, FTIR, UV-Vis, photoluminescence, electron paramagnetic resonance). Results show that all types of quantum dots has pro-oxidant and antioxidant potentials whereas GO demonstrated only moderate antioxidant effect. The best free radical scavenger is CQDs sample in the absence of light. CQDs are the best singlet oxygen generator under blue light irradiation as well. To check photo-cytotoxicity of these materials, photo-cytotoxic concentrations of the GO, GQDs, CQDs and N-CQDs were determined for three cellular lines: human rhabdomyosarcoma (RD), cell line derived from human cervix carcinoma Hep2c (HeLa) and fibroblast cell line from murine (L2OB). Cytotoxicity test has indicated that all samples are much less photocytotoxic than cis-diamminedichloroplatinum (cis-DPP). The production method and doping of quantum dots affect the photodynamic activity of tested samples very much.",
publisher = "Elsevier Science Sa, Lausanne",
journal = "Journal of Photochemistry and Photobiology B-Biology",
title = "Graphene oxide size and structure pro-oxidant and antioxidant activity and photoinduced cytotoxicity relation on three cancer cell lines",
volume = "200",
doi = "10.1016/j.jphotobiol.2019.111647"
}

Marković, Z. M., Jovanović, S. P., Masković, P. Z., Mojsin, M., Stevanović, M., Danko, M., Micusik, M., Jovanović, D. J., Kleinova, A., Spitalsky, Z., Pavlović, V. B.,& Marković, B. M. T.. (2019). Graphene oxide size and structure pro-oxidant and antioxidant activity and photoinduced cytotoxicity relation on three cancer cell lines. in Journal of Photochemistry and Photobiology B-Biology
Elsevier Science Sa, Lausanne., 200.
https://doi.org/10.1016/j.jphotobiol.2019.111647

Marković ZM, Jovanović SP, Masković PZ, Mojsin M, Stevanović M, Danko M, Micusik M, Jovanović DJ, Kleinova A, Spitalsky Z, Pavlović VB, Marković BMT. Graphene oxide size and structure pro-oxidant and antioxidant activity and photoinduced cytotoxicity relation on three cancer cell lines. in Journal of Photochemistry and Photobiology B-Biology. 2019;200.
doi:10.1016/j.jphotobiol.2019.111647 .

Marković, Zoran M., Jovanović, Svetlana P., Masković, Pavle Z., Mojsin, Marija, Stevanović, Milena, Danko, Martin, Micusik, Matej, Jovanović, Dragana J., Kleinova, Angela, Spitalsky, Zdeno, Pavlović, Vladimir B., Marković, Biljana M. Todorovic, "Graphene oxide size and structure pro-oxidant and antioxidant activity and photoinduced cytotoxicity relation on three cancer cell lines" in Journal of Photochemistry and Photobiology B-Biology, 200 (2019),
https://doi.org/10.1016/j.jphotobiol.2019.111647 . .

TY  - JOUR
AU  - Marković, Zoran M.
AU  - Matijašević, Danka
AU  - Pavlović, Vladimir B.
AU  - Jovanović, Svetlana P.
AU  - Holclajtner-Antunović, Ivanka D.
AU  - Spitalsky, Zdenko
AU  - Micusik, Matej
AU  - Dramicanin, Miroslav D.
AU  - Milivojević, Dusan D.
AU  - Nikšić, Miomir
AU  - Marković, Biljana M. Todorovic
PY  - 2017
UR  - https://imagine.imgge.bg.ac.rs/handle/123456789/1090
AB  - Electrochemically exfoliated graphene is functionalized graphene with potential application in biomedicine. Two most relevant biological features of this material are its electrical conductivity and excellent water dispersibility. In this study we have tried to establish the correlation between graphene structure and its antibacterial properties. The exfoliation process was performed in a two electrode-highly oriented pyrolytic graphite electrochemical cell. Solution of ammonium persulfate was used as an electrolyte. Exfoliated graphene sheets were dispersed in aqueous media and characterized by atomic force microscopy, scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, X photoelectron spectroscopy, X-ray diffraction, electron paramagnetic resonance, zeta potential, contact angle measurements and surface energy. Antibacterial assays have shown lack of the significant antibacterial activity. Major effect on bacteria was slight change of bacteria morphology. Membrane remained intact despite significant change of chemical content of membrane components.
PB  - Academic Press Inc Elsevier Science, San Diego
T2  - Journal of Colloid and Interface Science
T1  - Antibacterial potential of electrochemically exfoliated graphene sheets
EP  - 43
SP  - 30
VL  - 500
DO  - 10.1016/j.jcis.2017.03.110
ER  - 

@article{
author = "Marković, Zoran M. and Matijašević, Danka and Pavlović, Vladimir B. and Jovanović, Svetlana P. and Holclajtner-Antunović, Ivanka D. and Spitalsky, Zdenko and Micusik, Matej and Dramicanin, Miroslav D. and Milivojević, Dusan D. and Nikšić, Miomir and Marković, Biljana M. Todorovic",
year = "2017",
abstract = "Electrochemically exfoliated graphene is functionalized graphene with potential application in biomedicine. Two most relevant biological features of this material are its electrical conductivity and excellent water dispersibility. In this study we have tried to establish the correlation between graphene structure and its antibacterial properties. The exfoliation process was performed in a two electrode-highly oriented pyrolytic graphite electrochemical cell. Solution of ammonium persulfate was used as an electrolyte. Exfoliated graphene sheets were dispersed in aqueous media and characterized by atomic force microscopy, scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, X photoelectron spectroscopy, X-ray diffraction, electron paramagnetic resonance, zeta potential, contact angle measurements and surface energy. Antibacterial assays have shown lack of the significant antibacterial activity. Major effect on bacteria was slight change of bacteria morphology. Membrane remained intact despite significant change of chemical content of membrane components.",
publisher = "Academic Press Inc Elsevier Science, San Diego",
journal = "Journal of Colloid and Interface Science",
title = "Antibacterial potential of electrochemically exfoliated graphene sheets",
pages = "43-30",
volume = "500",
doi = "10.1016/j.jcis.2017.03.110"
}

Marković, Z. M., Matijašević, D., Pavlović, V. B., Jovanović, S. P., Holclajtner-Antunović, I. D., Spitalsky, Z., Micusik, M., Dramicanin, M. D., Milivojević, D. D., Nikšić, M.,& Marković, B. M. T.. (2017). Antibacterial potential of electrochemically exfoliated graphene sheets. in Journal of Colloid and Interface Science
Academic Press Inc Elsevier Science, San Diego., 500, 30-43.
https://doi.org/10.1016/j.jcis.2017.03.110

Marković ZM, Matijašević D, Pavlović VB, Jovanović SP, Holclajtner-Antunović ID, Spitalsky Z, Micusik M, Dramicanin MD, Milivojević DD, Nikšić M, Marković BMT. Antibacterial potential of electrochemically exfoliated graphene sheets. in Journal of Colloid and Interface Science. 2017;500:30-43.
doi:10.1016/j.jcis.2017.03.110 .

Marković, Zoran M., Matijašević, Danka, Pavlović, Vladimir B., Jovanović, Svetlana P., Holclajtner-Antunović, Ivanka D., Spitalsky, Zdenko, Micusik, Matej, Dramicanin, Miroslav D., Milivojević, Dusan D., Nikšić, Miomir, Marković, Biljana M. Todorovic, "Antibacterial potential of electrochemically exfoliated graphene sheets" in Journal of Colloid and Interface Science, 500 (2017):30-43,
https://doi.org/10.1016/j.jcis.2017.03.110 . .