TY  - JOUR
AU  - Krunić, Matija
AU  - Ristić, Biljana
AU  - Bošnjak, Mihajlo
AU  - Paunović, Verica
AU  - Tovilović-Kovačević, Gordana
AU  - Zogović, Nevena
AU  - Mirčić, Aleksandar
AU  - Marković, Zoran
AU  - Todorović-Marković, Biljana
AU  - Jovanović, Svetlana
AU  - Kleut, Duška
AU  - Mojović, Miloš
AU  - Nakarada, Đura
AU  - Marković, Olivera
AU  - Vuković, Irena
AU  - Harhaji-Trajković, Ljubica
AU  - Trajković, Vladimir
PY  - 2021
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/4812
AB  - We investigated the ability of graphene quantum dot (GQD) nanoparticles to protect SH-SY5Y human neuroblastoma cells from oxidative/nitrosative stress induced by iron-nitrosyl complex sodium nitroprusside (SNP).
GQD reduced SNP cytotoxicity by preventing mitochondrial depolarization, caspase-2 activation, and subsequent apoptotic death. Although GQD diminished the levels of nitric oxide (NO) in SNP-exposed cells, NO scavengers displayed only a slight protective effect, suggesting that NO quenching was not the main protective mechanism of GQD. GQD also reduced SNP-triggered increase in the intracellular levels of hydroxyl radical (•OH), superoxide anion (O2•- ), and lipid peroxidation. Nonselective antioxidants, •OH scavenging, and iron chelators, but not superoxide dismutase, mimicked GQD cytoprotective activity, indicating that GQD protect cells by neutralizing •OH generated in the presence of SNP-released iron. Cellular internalization of GQD was required for optimal protection, since a removal of extracellular GQD by extensive washing only partly diminished their protective effect. Moreover, GQD cooperated with SNP to induce autophagy, as confirmed by the inhibition of autophagylimiting Akt/PRAS40/mTOR signaling and increase in autophagy gene transcription, protein levels of proautophagic beclin-1 and LC3-II, formation of autophagic vesicles, and degradation of autophagic target p62. The antioxidant activity of GQD was not involved in autophagy induction, as antioxidants N-acetylcysteine and dimethyl sulfoxide failed to stimulate autophagy in SNP-exposed cells. Pharmacological inhibitors of early (wortmannin, 3-methyladenine) or late stages of autophagy (NH4Cl) efficiently reduced the protective effect of GQD. Therefore, the ability of GQD to prevent the in vitro neurotoxicity of SNP depends on both •OH/NO scavenging and induction of cytoprotective autophagy.
PB  - Elsevier
T2  - Free Radical Biology and Medicine
T1  - Graphene quantum dot antioxidant and proautophagic actions protect SH-SY5Y neuroblastoma cells from oxidative stress-mediated apoptotic death
VL  - 177
SP  - 167
EP  - 180
DO  - 10.1016/j.freeradbiomed.2021.10.025
ER  - 

@article{
author = "Krunić, Matija and Ristić, Biljana and Bošnjak, Mihajlo and Paunović, Verica and Tovilović-Kovačević, Gordana and Zogović, Nevena and Mirčić, Aleksandar and Marković, Zoran and Todorović-Marković, Biljana and Jovanović, Svetlana and Kleut, Duška and Mojović, Miloš and Nakarada, Đura and Marković, Olivera and Vuković, Irena and Harhaji-Trajković, Ljubica and Trajković, Vladimir",
year = "2021",
abstract = "We investigated the ability of graphene quantum dot (GQD) nanoparticles to protect SH-SY5Y human neuroblastoma cells from oxidative/nitrosative stress induced by iron-nitrosyl complex sodium nitroprusside (SNP).
GQD reduced SNP cytotoxicity by preventing mitochondrial depolarization, caspase-2 activation, and subsequent apoptotic death. Although GQD diminished the levels of nitric oxide (NO) in SNP-exposed cells, NO scavengers displayed only a slight protective effect, suggesting that NO quenching was not the main protective mechanism of GQD. GQD also reduced SNP-triggered increase in the intracellular levels of hydroxyl radical (•OH), superoxide anion (O2•- ), and lipid peroxidation. Nonselective antioxidants, •OH scavenging, and iron chelators, but not superoxide dismutase, mimicked GQD cytoprotective activity, indicating that GQD protect cells by neutralizing •OH generated in the presence of SNP-released iron. Cellular internalization of GQD was required for optimal protection, since a removal of extracellular GQD by extensive washing only partly diminished their protective effect. Moreover, GQD cooperated with SNP to induce autophagy, as confirmed by the inhibition of autophagylimiting Akt/PRAS40/mTOR signaling and increase in autophagy gene transcription, protein levels of proautophagic beclin-1 and LC3-II, formation of autophagic vesicles, and degradation of autophagic target p62. The antioxidant activity of GQD was not involved in autophagy induction, as antioxidants N-acetylcysteine and dimethyl sulfoxide failed to stimulate autophagy in SNP-exposed cells. Pharmacological inhibitors of early (wortmannin, 3-methyladenine) or late stages of autophagy (NH4Cl) efficiently reduced the protective effect of GQD. Therefore, the ability of GQD to prevent the in vitro neurotoxicity of SNP depends on both •OH/NO scavenging and induction of cytoprotective autophagy.",
publisher = "Elsevier",
journal = "Free Radical Biology and Medicine",
title = "Graphene quantum dot antioxidant and proautophagic actions protect SH-SY5Y neuroblastoma cells from oxidative stress-mediated apoptotic death",
volume = "177",
pages = "167-180",
doi = "10.1016/j.freeradbiomed.2021.10.025"
}

Krunić, M., Ristić, B., Bošnjak, M., Paunović, V., Tovilović-Kovačević, G., Zogović, N., Mirčić, A., Marković, Z., Todorović-Marković, B., Jovanović, S., Kleut, D., Mojović, M., Nakarada, Đ., Marković, O., Vuković, I., Harhaji-Trajković, L.,& Trajković, V.. (2021). Graphene quantum dot antioxidant and proautophagic actions protect SH-SY5Y neuroblastoma cells from oxidative stress-mediated apoptotic death. in Free Radical Biology and Medicine
Elsevier., 177, 167-180.
https://doi.org/10.1016/j.freeradbiomed.2021.10.025

Krunić M, Ristić B, Bošnjak M, Paunović V, Tovilović-Kovačević G, Zogović N, Mirčić A, Marković Z, Todorović-Marković B, Jovanović S, Kleut D, Mojović M, Nakarada Đ, Marković O, Vuković I, Harhaji-Trajković L, Trajković V. Graphene quantum dot antioxidant and proautophagic actions protect SH-SY5Y neuroblastoma cells from oxidative stress-mediated apoptotic death. in Free Radical Biology and Medicine. 2021;177:167-180.
doi:10.1016/j.freeradbiomed.2021.10.025 .

Krunić, Matija, Ristić, Biljana, Bošnjak, Mihajlo, Paunović, Verica, Tovilović-Kovačević, Gordana, Zogović, Nevena, Mirčić, Aleksandar, Marković, Zoran, Todorović-Marković, Biljana, Jovanović, Svetlana, Kleut, Duška, Mojović, Miloš, Nakarada, Đura, Marković, Olivera, Vuković, Irena, Harhaji-Trajković, Ljubica, Trajković, Vladimir, "Graphene quantum dot antioxidant and proautophagic actions protect SH-SY5Y neuroblastoma cells from oxidative stress-mediated apoptotic death" in Free Radical Biology and Medicine, 177 (2021):167-180,
https://doi.org/10.1016/j.freeradbiomed.2021.10.025 . .

TY  - JOUR
AU  - Krunić, Matija
AU  - Ristić, Biljana
AU  - Bošnjak, Mihajlo
AU  - Paunović, Verica
AU  - Tovilović-Kovačević, Gordana
AU  - Zogović, Nevena
AU  - Mirčić, Aleksandar
AU  - Marković, Zoran
AU  - Todorović-Marković, Biljana
AU  - Jovanović, Svetlana
AU  - Kleut, Duška
AU  - Mojović, Miloš
AU  - Nakarada, Đura
AU  - Marković, Olivera
AU  - Vuković, Irena
AU  - Harhaji-Trajković, Ljubica
AU  - Trajković, Vladimir
PY  - 2021
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/4818
AB  - We investigated the ability of graphene quantum dot (GQD) nanoparticles to protect SH-SY5Y human neuroblastoma cells from oxidative/nitrosative stress induced by iron-nitrosyl complex sodium nitroprusside (SNP).GQD reduced SNP cytotoxicity by preventing mitochondrial depolarization, caspase-2 activation, and subsequent apoptotic death. Although GQD diminished the levels of nitric oxide (NO) in SNP-exposed cells, NO scavengers displayed only a slight protective effect, suggesting that NO quenching was not the main protective mechanism of GQD. GQD also reduced SNP-triggered increase in the intracellular levels of hydroxyl radical (•OH), superoxide anion (O2•- ), and lipid peroxidation. Nonselective antioxidants, •OH scavenging, and iron chelators, but not superoxide dismutase, mimicked GQD cytoprotective activity, indicating that GQD protect cells by neutralizing •OH generated in the presence of SNP-released iron. Cellular internalization of GQD was required for optimal protection, since a removal of extracellular GQD by extensive washing only partly diminished their protective effect. Moreover, GQD cooperated with SNP to induce autophagy, as confirmed by the inhibition of autophagylimiting Akt/PRAS40/mTOR signaling and increase in autophagy gene transcription, protein levels of proautophagic beclin-1 and LC3-II, formation of autophagic vesicles, and degradation of autophagic target p62. The antioxidant activity of GQD was not involved in autophagy induction, as antioxidants N-acetylcysteine and dimethyl sulfoxide failed to stimulate autophagy in SNP-exposed cells. Pharmacological inhibitors of early (wortmannin, 3-methyladenine) or late stages of autophagy (NH4Cl) efficiently reduced the protective effect of GQD. Therefore, the ability of GQD to prevent the in vitro neurotoxicity of SNP depends on both •OH/NO scavenging and induction of cytoprotective autophagy.
PB  - Elsevier
T2  - Free Radical Biology and Medicine
T1  - Graphene quantum dot antioxidant and proautophagic actions protect SH-SY5Y neuroblastoma cells from oxidative stress-mediated apoptotic death
VL  - 177
SP  - 167
EP  - 180
DO  - 10.1016/j.freeradbiomed.2021.10.025
ER  - 

@article{
author = "Krunić, Matija and Ristić, Biljana and Bošnjak, Mihajlo and Paunović, Verica and Tovilović-Kovačević, Gordana and Zogović, Nevena and Mirčić, Aleksandar and Marković, Zoran and Todorović-Marković, Biljana and Jovanović, Svetlana and Kleut, Duška and Mojović, Miloš and Nakarada, Đura and Marković, Olivera and Vuković, Irena and Harhaji-Trajković, Ljubica and Trajković, Vladimir",
year = "2021",
abstract = "We investigated the ability of graphene quantum dot (GQD) nanoparticles to protect SH-SY5Y human neuroblastoma cells from oxidative/nitrosative stress induced by iron-nitrosyl complex sodium nitroprusside (SNP).GQD reduced SNP cytotoxicity by preventing mitochondrial depolarization, caspase-2 activation, and subsequent apoptotic death. Although GQD diminished the levels of nitric oxide (NO) in SNP-exposed cells, NO scavengers displayed only a slight protective effect, suggesting that NO quenching was not the main protective mechanism of GQD. GQD also reduced SNP-triggered increase in the intracellular levels of hydroxyl radical (•OH), superoxide anion (O2•- ), and lipid peroxidation. Nonselective antioxidants, •OH scavenging, and iron chelators, but not superoxide dismutase, mimicked GQD cytoprotective activity, indicating that GQD protect cells by neutralizing •OH generated in the presence of SNP-released iron. Cellular internalization of GQD was required for optimal protection, since a removal of extracellular GQD by extensive washing only partly diminished their protective effect. Moreover, GQD cooperated with SNP to induce autophagy, as confirmed by the inhibition of autophagylimiting Akt/PRAS40/mTOR signaling and increase in autophagy gene transcription, protein levels of proautophagic beclin-1 and LC3-II, formation of autophagic vesicles, and degradation of autophagic target p62. The antioxidant activity of GQD was not involved in autophagy induction, as antioxidants N-acetylcysteine and dimethyl sulfoxide failed to stimulate autophagy in SNP-exposed cells. Pharmacological inhibitors of early (wortmannin, 3-methyladenine) or late stages of autophagy (NH4Cl) efficiently reduced the protective effect of GQD. Therefore, the ability of GQD to prevent the in vitro neurotoxicity of SNP depends on both •OH/NO scavenging and induction of cytoprotective autophagy.",
publisher = "Elsevier",
journal = "Free Radical Biology and Medicine",
title = "Graphene quantum dot antioxidant and proautophagic actions protect SH-SY5Y neuroblastoma cells from oxidative stress-mediated apoptotic death",
volume = "177",
pages = "167-180",
doi = "10.1016/j.freeradbiomed.2021.10.025"
}

Krunić, M., Ristić, B., Bošnjak, M., Paunović, V., Tovilović-Kovačević, G., Zogović, N., Mirčić, A., Marković, Z., Todorović-Marković, B., Jovanović, S., Kleut, D., Mojović, M., Nakarada, Đ., Marković, O., Vuković, I., Harhaji-Trajković, L.,& Trajković, V.. (2021). Graphene quantum dot antioxidant and proautophagic actions protect SH-SY5Y neuroblastoma cells from oxidative stress-mediated apoptotic death. in Free Radical Biology and Medicine
Elsevier., 177, 167-180.
https://doi.org/10.1016/j.freeradbiomed.2021.10.025

Krunić M, Ristić B, Bošnjak M, Paunović V, Tovilović-Kovačević G, Zogović N, Mirčić A, Marković Z, Todorović-Marković B, Jovanović S, Kleut D, Mojović M, Nakarada Đ, Marković O, Vuković I, Harhaji-Trajković L, Trajković V. Graphene quantum dot antioxidant and proautophagic actions protect SH-SY5Y neuroblastoma cells from oxidative stress-mediated apoptotic death. in Free Radical Biology and Medicine. 2021;177:167-180.
doi:10.1016/j.freeradbiomed.2021.10.025 .

Krunić, Matija, Ristić, Biljana, Bošnjak, Mihajlo, Paunović, Verica, Tovilović-Kovačević, Gordana, Zogović, Nevena, Mirčić, Aleksandar, Marković, Zoran, Todorović-Marković, Biljana, Jovanović, Svetlana, Kleut, Duška, Mojović, Miloš, Nakarada, Đura, Marković, Olivera, Vuković, Irena, Harhaji-Trajković, Ljubica, Trajković, Vladimir, "Graphene quantum dot antioxidant and proautophagic actions protect SH-SY5Y neuroblastoma cells from oxidative stress-mediated apoptotic death" in Free Radical Biology and Medicine, 177 (2021):167-180,
https://doi.org/10.1016/j.freeradbiomed.2021.10.025 . .

TY  - CONF
AU  - Dorontić, Slađana
AU  - Marković, Olivera
AU  - Kleut, Duška
AU  - Jovanović, Svetlana
PY  - 2021
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/4882
AB  - Graphene quantum dots (GQDs) were fabricated by simple electrochemical oxidation of 
graphite electrodes. Modified GQDs were obtained by gamma irradiation of GQDs, EDA, and 
IPA mixture at a dose of 25 kGy. In this approach, GQDs with the amino groups were produced 
(25γ-GQDs). These GQDs have shown a high uniformity, good dispersibility in water, and 
strong photoluminescence in the blue part of the electromagnetic spectrum. Modified GQDs 
were studied in the optical detection of Co2+ ions. The PL intensities of GQDs were measured 
in the presence of Co2+ ions in the concentration range 0-7.5 µmol L-1. It was demonstrated that PL intensities decreased linearly in the concentration range 0-2.5 µmol L-1. The value of the coefficient of determination (R2= 0.95949) indicates the potential of 25γ-GQDs for application 
in optical sensing of Co2+ ions.
PB  - Szeged, Hungary : University of Szeged
C3  - Proceedings - The 27th International Symposium on Analytical and  Environmental Problems
T1  - Amino functionalized graphene quantum dots - new fluorescent sensor for Co2+ ions
SP  - 107
EP  - 111
UR  - https://hdl.handle.net/21.15107/rcub_cer_4882
ER  - 

@conference{
author = "Dorontić, Slađana and Marković, Olivera and Kleut, Duška and Jovanović, Svetlana",
year = "2021",
abstract = "Graphene quantum dots (GQDs) were fabricated by simple electrochemical oxidation of 
graphite electrodes. Modified GQDs were obtained by gamma irradiation of GQDs, EDA, and 
IPA mixture at a dose of 25 kGy. In this approach, GQDs with the amino groups were produced 
(25γ-GQDs). These GQDs have shown a high uniformity, good dispersibility in water, and 
strong photoluminescence in the blue part of the electromagnetic spectrum. Modified GQDs 
were studied in the optical detection of Co2+ ions. The PL intensities of GQDs were measured 
in the presence of Co2+ ions in the concentration range 0-7.5 µmol L-1. It was demonstrated that PL intensities decreased linearly in the concentration range 0-2.5 µmol L-1. The value of the coefficient of determination (R2= 0.95949) indicates the potential of 25γ-GQDs for application 
in optical sensing of Co2+ ions.",
publisher = "Szeged, Hungary : University of Szeged",
journal = "Proceedings - The 27th International Symposium on Analytical and  Environmental Problems",
title = "Amino functionalized graphene quantum dots - new fluorescent sensor for Co2+ ions",
pages = "107-111",
url = "https://hdl.handle.net/21.15107/rcub_cer_4882"
}

Dorontić, S., Marković, O., Kleut, D.,& Jovanović, S.. (2021). Amino functionalized graphene quantum dots - new fluorescent sensor for Co2+ ions. in Proceedings - The 27th International Symposium on Analytical and  Environmental Problems
Szeged, Hungary : University of Szeged., 107-111.
https://hdl.handle.net/21.15107/rcub_cer_4882

Dorontić S, Marković O, Kleut D, Jovanović S. Amino functionalized graphene quantum dots - new fluorescent sensor for Co2+ ions. in Proceedings - The 27th International Symposium on Analytical and  Environmental Problems. 2021;:107-111.
https://hdl.handle.net/21.15107/rcub_cer_4882 .

Dorontić, Slađana, Marković, Olivera, Kleut, Duška, Jovanović, Svetlana, "Amino functionalized graphene quantum dots - new fluorescent sensor for Co2+ ions" in Proceedings - The 27th International Symposium on Analytical and  Environmental Problems (2021):107-111,
https://hdl.handle.net/21.15107/rcub_cer_4882 .

TY  - CONF
AU  - Dorontić, Slađana
AU  - Marković, Olivera
AU  - Kleut, Duška
AU  - Jovanović, Svetlana
PY  - 2021
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/4879
AB  - We produced Graphene Quantum Dots (GQDs) by electrochemical oxidation of graphite rods 
and exposed them to gamma irradiation at a dose of 200 kGy, in the presence of ethylene-diamine. Before irradiation, oxygen was removed from the GQDs dispersion by purging with Ar. These conditions induced both chemical reduction as well as the incorporation of N atoms 
in the structure of GQDs. Thus, N-doped GQDs were produced. The morphology of dots was 
investigated using atomic force microscopy. UV-Vis and photoluminescence spectroscopy 
were used to investigate the optical properties of modified GQDs. The changes in the intensities
of PL emission spectra were studied in the presence of different concentrations of Pd2+ and 
pesticide carbofuran. We observed promising results for the application of N-doped GQDs for 
non-enzymatic PL detection of selected metal ions and molecules of pesticide.
PB  - Szeged, Hungary : University of Szeged
C3  - The 27th International Symposium on Analytical and Environmental Problems
T1  - N-doped graphene quantum dots for detection of palladium(II) ions and carbofuran
SP  - 143
EP  - 147
UR  - https://hdl.handle.net/21.15107/rcub_cer_4879
ER  - 

@conference{
author = "Dorontić, Slađana and Marković, Olivera and Kleut, Duška and Jovanović, Svetlana",
year = "2021",
abstract = "We produced Graphene Quantum Dots (GQDs) by electrochemical oxidation of graphite rods 
and exposed them to gamma irradiation at a dose of 200 kGy, in the presence of ethylene-diamine. Before irradiation, oxygen was removed from the GQDs dispersion by purging with Ar. These conditions induced both chemical reduction as well as the incorporation of N atoms 
in the structure of GQDs. Thus, N-doped GQDs were produced. The morphology of dots was 
investigated using atomic force microscopy. UV-Vis and photoluminescence spectroscopy 
were used to investigate the optical properties of modified GQDs. The changes in the intensities
of PL emission spectra were studied in the presence of different concentrations of Pd2+ and 
pesticide carbofuran. We observed promising results for the application of N-doped GQDs for 
non-enzymatic PL detection of selected metal ions and molecules of pesticide.",
publisher = "Szeged, Hungary : University of Szeged",
journal = "The 27th International Symposium on Analytical and Environmental Problems",
title = "N-doped graphene quantum dots for detection of palladium(II) ions and carbofuran",
pages = "143-147",
url = "https://hdl.handle.net/21.15107/rcub_cer_4879"
}

Dorontić, S., Marković, O., Kleut, D.,& Jovanović, S.. (2021). N-doped graphene quantum dots for detection of palladium(II) ions and carbofuran. in The 27th International Symposium on Analytical and Environmental Problems
Szeged, Hungary : University of Szeged., 143-147.
https://hdl.handle.net/21.15107/rcub_cer_4879

Dorontić S, Marković O, Kleut D, Jovanović S. N-doped graphene quantum dots for detection of palladium(II) ions and carbofuran. in The 27th International Symposium on Analytical and Environmental Problems. 2021;:143-147.
https://hdl.handle.net/21.15107/rcub_cer_4879 .

Dorontić, Slađana, Marković, Olivera, Kleut, Duška, Jovanović, Svetlana, "N-doped graphene quantum dots for detection of palladium(II) ions and carbofuran" in The 27th International Symposium on Analytical and Environmental Problems (2021):143-147,
https://hdl.handle.net/21.15107/rcub_cer_4879 .

TY  - CONF
AU  - Dorontić, Slađana
AU  - Marković, Olivera
AU  - Kleut, Duška
AU  - Jovanović, Svetlana
PY  - 2021
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/4890
AB  - In the era of pollution and hazardous materials, new methods for the detection of pollutants
in the environment are urgently needed. Due to their specific features such as
photoluminescence (PL) in the visible part of the spectrum, dispersibility in water, and
organic solvents, nontoxicity, and biocompatibility, graphene quantum dots (GQDs) attract
attention in optical sensing of various ions and molecules. In this study, pristine graphene
quantum dots (p-GQDs) were produced in a simple single-step electrochemical top-down
approach using graphite electrodes as a starting material, and dispersion of sodium-hydroxide in 96% ethanol as a medium for electrochemical reaction. These p-GQDs were
gamma-irradiated in a dose of 25 kGy in presence of ethylenediamine in Ar medium to
introduce amino groups in their crystal lattice. Results obtained from AFM microscopy
indicate the height-uniformity of irradiated GQDs. The presence of amino groups in GQDs
was confirmed by FTIR, XPS, and UV-Vis spectroscopies. According to results obtained
from PL spectroscopy, a significant narrowing of emission band in irradiated GQDs was
observed. In further research, these GQDs were investigated as a potential PL sensor for iron
which is one of the most abundant heavy metal in the environment. In the preliminary
investigation, a water dispersion of irradiated GQDs was mixed with Fe(III) solution in
concentrations of 50 and 100 µM. Using a PL spectroscopy the PL intensity of irradiated
GQDs in presence of Fe (III) was measured. From the obtained results, it can be seen that
Fe(III) ions lead to quenching of GQDs PL intensity. Then, PL intensities were measured in
presence of Fe(III) ions in concentration range 0-100 µM. With an increase of Fe(III)
concentration, the PL intensity of GQDs decreased. It can be concluded that gamma-irradiated amino-doped GQDs have significant potential in the so-called ,,turn of“ detection
of Fe(III) ions in the aqueous medium
PB  - Belgrade, Serbia : Institute of Technical Sciences of SASA
C3  - Program and the Book of Abstracts - Nineteenth Young Researchers Conference – Materials Science and Engineering
T1  - Graphene quantum dots with amino groups as a potential photoluminescent probe for Fe(III) ions
SP  - 35
EP  - 35
UR  - https://hdl.handle.net/21.15107/rcub_cer_4890
ER  - 

@conference{
author = "Dorontić, Slađana and Marković, Olivera and Kleut, Duška and Jovanović, Svetlana",
year = "2021",
abstract = "In the era of pollution and hazardous materials, new methods for the detection of pollutants
in the environment are urgently needed. Due to their specific features such as
photoluminescence (PL) in the visible part of the spectrum, dispersibility in water, and
organic solvents, nontoxicity, and biocompatibility, graphene quantum dots (GQDs) attract
attention in optical sensing of various ions and molecules. In this study, pristine graphene
quantum dots (p-GQDs) were produced in a simple single-step electrochemical top-down
approach using graphite electrodes as a starting material, and dispersion of sodium-hydroxide in 96% ethanol as a medium for electrochemical reaction. These p-GQDs were
gamma-irradiated in a dose of 25 kGy in presence of ethylenediamine in Ar medium to
introduce amino groups in their crystal lattice. Results obtained from AFM microscopy
indicate the height-uniformity of irradiated GQDs. The presence of amino groups in GQDs
was confirmed by FTIR, XPS, and UV-Vis spectroscopies. According to results obtained
from PL spectroscopy, a significant narrowing of emission band in irradiated GQDs was
observed. In further research, these GQDs were investigated as a potential PL sensor for iron
which is one of the most abundant heavy metal in the environment. In the preliminary
investigation, a water dispersion of irradiated GQDs was mixed with Fe(III) solution in
concentrations of 50 and 100 µM. Using a PL spectroscopy the PL intensity of irradiated
GQDs in presence of Fe (III) was measured. From the obtained results, it can be seen that
Fe(III) ions lead to quenching of GQDs PL intensity. Then, PL intensities were measured in
presence of Fe(III) ions in concentration range 0-100 µM. With an increase of Fe(III)
concentration, the PL intensity of GQDs decreased. It can be concluded that gamma-irradiated amino-doped GQDs have significant potential in the so-called ,,turn of“ detection
of Fe(III) ions in the aqueous medium",
publisher = "Belgrade, Serbia : Institute of Technical Sciences of SASA",
journal = "Program and the Book of Abstracts - Nineteenth Young Researchers Conference – Materials Science and Engineering",
title = "Graphene quantum dots with amino groups as a potential photoluminescent probe for Fe(III) ions",
pages = "35-35",
url = "https://hdl.handle.net/21.15107/rcub_cer_4890"
}

Dorontić, S., Marković, O., Kleut, D.,& Jovanović, S.. (2021). Graphene quantum dots with amino groups as a potential photoluminescent probe for Fe(III) ions. in Program and the Book of Abstracts - Nineteenth Young Researchers Conference – Materials Science and Engineering
Belgrade, Serbia : Institute of Technical Sciences of SASA., 35-35.
https://hdl.handle.net/21.15107/rcub_cer_4890

Dorontić S, Marković O, Kleut D, Jovanović S. Graphene quantum dots with amino groups as a potential photoluminescent probe for Fe(III) ions. in Program and the Book of Abstracts - Nineteenth Young Researchers Conference – Materials Science and Engineering. 2021;:35-35.
https://hdl.handle.net/21.15107/rcub_cer_4890 .

Dorontić, Slađana, Marković, Olivera, Kleut, Duška, Jovanović, Svetlana, "Graphene quantum dots with amino groups as a potential photoluminescent probe for Fe(III) ions" in Program and the Book of Abstracts - Nineteenth Young Researchers Conference – Materials Science and Engineering (2021):35-35,
https://hdl.handle.net/21.15107/rcub_cer_4890 .