TY  - JOUR
AU  - Dorontić, Slađana
AU  - Bonasera, Aurelio
AU  - Scopelliti, Michelangelo
AU  - Marković, Olivera
AU  - Bajuk-Bogdanović, Danica
AU  - Ciasca, Gabriele
AU  - Romanò, Sabrina
AU  - Dimkić, Ivica
AU  - Budimir, Milica
AU  - Marinković, Dragana
AU  - Jovanović, Svetlana
PY  - 2022
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5222
AB  - Structural modification of different carbon-based nanomaterials is often necessary to improve their morphology and optical properties, particularly the incorporation of N-atoms in graphene quantum dots (GQDs). Here, a clean, simple, one-step, and eco-friendly method for N-doping of GQDs using gamma irradiation is reported. GQDs were irradiated in the presence of the different ethylenediamine (EDA) amounts (1 g, 5 g, and 10 g) and the highest % of N was detected in the presence of 10 g. N-doped GQDs emitted strong, blue photoluminescence (PL). Photoluminescence quantum yield was increased from 1.45, as obtained for non-irradiated dots, to 7.24% for those irradiated in the presence of 1 g of EDA. Modified GQDs were investigated as a PL probe for the detection of insecticide Carbofuran (2,2-Dimethyl-2,3-dihydro-1-benzofuran-7-yl methylcarbamate) and herbicide Amitrole (3-amino-1,2,4-triazole). The limit of detection was 5.4 μmol L−1 for Carbofuran. For the first time, Amitrole was detected by GQDs in a turn-off/turn-on mechanism using Pd(II) ions as a quenching agent. First, Pd(II) ions were quenched (turn-off) PL of GQDs, while after Amitrole addition, PL was recovered linearly with Amitrole concentration (turn-on). LOD was 2.03 μmol L−1. These results suggest that modified GQDs can be used as an efficient new material for Carbofuran and Amitrole detection. Furthermore, the phototoxicity of dots was investigated on both Gram-positive and Gram-negative bacterial strains. When bacterial cells were exposed to different GQD concentrations and illuminated with light of 470 nm wavelength, the toxic effects were not observed.
PB  - MDPI
T2  - Nanomaterials
T1  - Gamma-Ray-Induced Structural Transformation of GQDs towards the Improvement of Their Optical Properties, Monitoring of Selected Toxic Compounds, and Photo-Induced Effects on Bacterial Strains
VL  - 12
IS  - 15
SP  - 2714
DO  - 10.3390/nano12152714
ER  - 

@article{
author = "Dorontić, Slađana and Bonasera, Aurelio and Scopelliti, Michelangelo and Marković, Olivera and Bajuk-Bogdanović, Danica and Ciasca, Gabriele and Romanò, Sabrina and Dimkić, Ivica and Budimir, Milica and Marinković, Dragana and Jovanović, Svetlana",
year = "2022",
abstract = "Structural modification of different carbon-based nanomaterials is often necessary to improve their morphology and optical properties, particularly the incorporation of N-atoms in graphene quantum dots (GQDs). Here, a clean, simple, one-step, and eco-friendly method for N-doping of GQDs using gamma irradiation is reported. GQDs were irradiated in the presence of the different ethylenediamine (EDA) amounts (1 g, 5 g, and 10 g) and the highest % of N was detected in the presence of 10 g. N-doped GQDs emitted strong, blue photoluminescence (PL). Photoluminescence quantum yield was increased from 1.45, as obtained for non-irradiated dots, to 7.24% for those irradiated in the presence of 1 g of EDA. Modified GQDs were investigated as a PL probe for the detection of insecticide Carbofuran (2,2-Dimethyl-2,3-dihydro-1-benzofuran-7-yl methylcarbamate) and herbicide Amitrole (3-amino-1,2,4-triazole). The limit of detection was 5.4 μmol L−1 for Carbofuran. For the first time, Amitrole was detected by GQDs in a turn-off/turn-on mechanism using Pd(II) ions as a quenching agent. First, Pd(II) ions were quenched (turn-off) PL of GQDs, while after Amitrole addition, PL was recovered linearly with Amitrole concentration (turn-on). LOD was 2.03 μmol L−1. These results suggest that modified GQDs can be used as an efficient new material for Carbofuran and Amitrole detection. Furthermore, the phototoxicity of dots was investigated on both Gram-positive and Gram-negative bacterial strains. When bacterial cells were exposed to different GQD concentrations and illuminated with light of 470 nm wavelength, the toxic effects were not observed.",
publisher = "MDPI",
journal = "Nanomaterials",
title = "Gamma-Ray-Induced Structural Transformation of GQDs towards the Improvement of Their Optical Properties, Monitoring of Selected Toxic Compounds, and Photo-Induced Effects on Bacterial Strains",
volume = "12",
number = "15",
pages = "2714",
doi = "10.3390/nano12152714"
}

Dorontić, S., Bonasera, A., Scopelliti, M., Marković, O., Bajuk-Bogdanović, D., Ciasca, G., Romanò, S., Dimkić, I., Budimir, M., Marinković, D.,& Jovanović, S.. (2022). Gamma-Ray-Induced Structural Transformation of GQDs towards the Improvement of Their Optical Properties, Monitoring of Selected Toxic Compounds, and Photo-Induced Effects on Bacterial Strains. in Nanomaterials
MDPI., 12(15), 2714.
https://doi.org/10.3390/nano12152714

Dorontić S, Bonasera A, Scopelliti M, Marković O, Bajuk-Bogdanović D, Ciasca G, Romanò S, Dimkić I, Budimir M, Marinković D, Jovanović S. Gamma-Ray-Induced Structural Transformation of GQDs towards the Improvement of Their Optical Properties, Monitoring of Selected Toxic Compounds, and Photo-Induced Effects on Bacterial Strains. in Nanomaterials. 2022;12(15):2714.
doi:10.3390/nano12152714 .

Dorontić, Slađana, Bonasera, Aurelio, Scopelliti, Michelangelo, Marković, Olivera, Bajuk-Bogdanović, Danica, Ciasca, Gabriele, Romanò, Sabrina, Dimkić, Ivica, Budimir, Milica, Marinković, Dragana, Jovanović, Svetlana, "Gamma-Ray-Induced Structural Transformation of GQDs towards the Improvement of Their Optical Properties, Monitoring of Selected Toxic Compounds, and Photo-Induced Effects on Bacterial Strains" in Nanomaterials, 12, no. 15 (2022):2714,
https://doi.org/10.3390/nano12152714 . .

TY  - JOUR
AU  - Dorontić, Slađana
AU  - Bonasera, Aurelio
AU  - Scopelliti, Michelangelo
AU  - Mojsin, Marija
AU  - Stevanović, Milena J.
AU  - Marković, Olivera
AU  - Jovanović, Svetlana
PY  - 2022
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5388
AB  - Large amounts of hazardous and toxic substances in the environment require non-toxic, cheap, easy, rapid, and sensitive methods for their detection. Blue luminescent graphene quantum dots (GQDs) were produced by electrochemical cleavage of graphite electrodes followed by gamma irradiation in the presence of ethylenediamine (EDA). Modified dots were able to detect metal ions (Co2+, Pd2+, Fe3+) due to photoluminescence quenching. The highest sensitivity was detected for the sample irradiated at a dose of 25 kGy. The limits of detection (LODs) were 1.79, 2.55, and 0.66 μmol L−1 for Co2+, Fe3+, and Pd2+, respectively. It was observed that GQDs irradiated at 200 kGy act as an ultra-sensitive turn-on probe for Malathion detection with LOD of 94 nmol L−1. Atomic force microscopy images proved the aggregation of GQDs in the presence of the investigated metal ions. Results obtained by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and LIVE/DEAD cytotoxicity test indicated that GQDs irradiated with EDA are not toxic towards MRC-5 cells, which makes them a promising, eco-friendly and safe material for sensing application.
PB  - Elsevier
T2  - Journal of Luminescence
T1  - Blue luminescent amino-functionalized graphene quantum dots as a responsive material for potential detection of metal ions and malathion
VL  - 252
SP  - 119311
DO  - 10.1016/j.jlumin.2022.119311
ER  - 

@article{
author = "Dorontić, Slađana and Bonasera, Aurelio and Scopelliti, Michelangelo and Mojsin, Marija and Stevanović, Milena J. and Marković, Olivera and Jovanović, Svetlana",
year = "2022",
abstract = "Large amounts of hazardous and toxic substances in the environment require non-toxic, cheap, easy, rapid, and sensitive methods for their detection. Blue luminescent graphene quantum dots (GQDs) were produced by electrochemical cleavage of graphite electrodes followed by gamma irradiation in the presence of ethylenediamine (EDA). Modified dots were able to detect metal ions (Co2+, Pd2+, Fe3+) due to photoluminescence quenching. The highest sensitivity was detected for the sample irradiated at a dose of 25 kGy. The limits of detection (LODs) were 1.79, 2.55, and 0.66 μmol L−1 for Co2+, Fe3+, and Pd2+, respectively. It was observed that GQDs irradiated at 200 kGy act as an ultra-sensitive turn-on probe for Malathion detection with LOD of 94 nmol L−1. Atomic force microscopy images proved the aggregation of GQDs in the presence of the investigated metal ions. Results obtained by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and LIVE/DEAD cytotoxicity test indicated that GQDs irradiated with EDA are not toxic towards MRC-5 cells, which makes them a promising, eco-friendly and safe material for sensing application.",
publisher = "Elsevier",
journal = "Journal of Luminescence",
title = "Blue luminescent amino-functionalized graphene quantum dots as a responsive material for potential detection of metal ions and malathion",
volume = "252",
pages = "119311",
doi = "10.1016/j.jlumin.2022.119311"
}

Dorontić, S., Bonasera, A., Scopelliti, M., Mojsin, M., Stevanović, M. J., Marković, O.,& Jovanović, S.. (2022). Blue luminescent amino-functionalized graphene quantum dots as a responsive material for potential detection of metal ions and malathion. in Journal of Luminescence
Elsevier., 252, 119311.
https://doi.org/10.1016/j.jlumin.2022.119311

Dorontić S, Bonasera A, Scopelliti M, Mojsin M, Stevanović MJ, Marković O, Jovanović S. Blue luminescent amino-functionalized graphene quantum dots as a responsive material for potential detection of metal ions and malathion. in Journal of Luminescence. 2022;252:119311.
doi:10.1016/j.jlumin.2022.119311 .

Dorontić, Slađana, Bonasera, Aurelio, Scopelliti, Michelangelo, Mojsin, Marija, Stevanović, Milena J., Marković, Olivera, Jovanović, Svetlana, "Blue luminescent amino-functionalized graphene quantum dots as a responsive material for potential detection of metal ions and malathion" in Journal of Luminescence, 252 (2022):119311,
https://doi.org/10.1016/j.jlumin.2022.119311 . .

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 .

TY  - JOUR
AU  - Jovanović, Svetlana
AU  - Dorontić, Slađana
AU  - Jovanović, Dragana
AU  - Ciasca, Gabriele
AU  - Budimir, Milica
AU  - Bonasera, Aurelio
AU  - Scopelliti, Michelangelo
AU  - Marković, Olivera
AU  - Todorović Marković, Biljana
PY  - 2020
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3593
AB  - Due to the low consumption of chemicals, the absence of toxic residual side products, the procedure simplicity and time-saving aspects, gamma irradiation offers advantages over the classical chemical protocols. We successfully employed gamma irradiation in order to introduce N-atoms in Graphene Quantum Dots (GQDs). By irradiating GQDs water dispersions in the presence of isopropyl alcohol and ethylenediamine, at doses of 25, 50 and 200 kGy, we attached amino groups onto GQDs in a single synthetic step. At the same time, a chemical reduction is achieved, too. Selected conditions induced incorporation of N-atoms within GDQs atomic lattice (around 3 at%), at all applied doses. Additionally, the C-atoms percentage was highly increased, from 63 to 79 at % or higher. The zeta potential of dots changed from −34.6 to +9.1 mV, due to the modification of functionalizing groups localized at the surface. Produced chemical changes lead to the desired alteration of the GQDs optical properties, such as an increased photoluminescence intensity, a higher photoluminescence quantum yields (from 2.07 to 18.40%) and a narrowing of the spectral features in the emission spectra. The ability of gamma-irradiated GQDs to quench free radical species was investigated and positively assessed; additionally, non-enzymatic optical detection of Cu(II) ions using GQDs as a sensor was studied and the detection limits are
herein reported. These results suggest that GQDs can be potentially applied as smart photoluminescent sensors for metal cations.
PB  - Elsevier
T2  - Ceramics International
T1  - Gamma irradiation of graphene quantum dots with ethylenediamine: Antioxidant for ion sensing
VL  - 46
IS  - 15
SP  - 23611
EP  - 23622
DO  - 10.1016/j.ceramint.2020.06.133
ER  - 

@article{
author = "Jovanović, Svetlana and Dorontić, Slađana and Jovanović, Dragana and Ciasca, Gabriele and Budimir, Milica and Bonasera, Aurelio and Scopelliti, Michelangelo and Marković, Olivera and Todorović Marković, Biljana",
year = "2020",
abstract = "Due to the low consumption of chemicals, the absence of toxic residual side products, the procedure simplicity and time-saving aspects, gamma irradiation offers advantages over the classical chemical protocols. We successfully employed gamma irradiation in order to introduce N-atoms in Graphene Quantum Dots (GQDs). By irradiating GQDs water dispersions in the presence of isopropyl alcohol and ethylenediamine, at doses of 25, 50 and 200 kGy, we attached amino groups onto GQDs in a single synthetic step. At the same time, a chemical reduction is achieved, too. Selected conditions induced incorporation of N-atoms within GDQs atomic lattice (around 3 at%), at all applied doses. Additionally, the C-atoms percentage was highly increased, from 63 to 79 at % or higher. The zeta potential of dots changed from −34.6 to +9.1 mV, due to the modification of functionalizing groups localized at the surface. Produced chemical changes lead to the desired alteration of the GQDs optical properties, such as an increased photoluminescence intensity, a higher photoluminescence quantum yields (from 2.07 to 18.40%) and a narrowing of the spectral features in the emission spectra. The ability of gamma-irradiated GQDs to quench free radical species was investigated and positively assessed; additionally, non-enzymatic optical detection of Cu(II) ions using GQDs as a sensor was studied and the detection limits are
herein reported. These results suggest that GQDs can be potentially applied as smart photoluminescent sensors for metal cations.",
publisher = "Elsevier",
journal = "Ceramics International",
title = "Gamma irradiation of graphene quantum dots with ethylenediamine: Antioxidant for ion sensing",
volume = "46",
number = "15",
pages = "23611-23622",
doi = "10.1016/j.ceramint.2020.06.133"
}

Jovanović, S., Dorontić, S., Jovanović, D., Ciasca, G., Budimir, M., Bonasera, A., Scopelliti, M., Marković, O.,& Todorović Marković, B.. (2020). Gamma irradiation of graphene quantum dots with ethylenediamine: Antioxidant for ion sensing. in Ceramics International
Elsevier., 46(15), 23611-23622.
https://doi.org/10.1016/j.ceramint.2020.06.133

Jovanović S, Dorontić S, Jovanović D, Ciasca G, Budimir M, Bonasera A, Scopelliti M, Marković O, Todorović Marković B. Gamma irradiation of graphene quantum dots with ethylenediamine: Antioxidant for ion sensing. in Ceramics International. 2020;46(15):23611-23622.
doi:10.1016/j.ceramint.2020.06.133 .

Jovanović, Svetlana, Dorontić, Slađana, Jovanović, Dragana, Ciasca, Gabriele, Budimir, Milica, Bonasera, Aurelio, Scopelliti, Michelangelo, Marković, Olivera, Todorović Marković, Biljana, "Gamma irradiation of graphene quantum dots with ethylenediamine: Antioxidant for ion sensing" in Ceramics International, 46, no. 15 (2020):23611-23622,
https://doi.org/10.1016/j.ceramint.2020.06.133 . .

TY  - JOUR
AU  - Jovanović, Svetlana
AU  - Dorontić, Slađana
AU  - Jovanović, Dragana
AU  - Ciasca, Gabriele
AU  - Budimir, Milica
AU  - Bonasera, Aurelio
AU  - Scopelliti, Michelangelo
AU  - Marković, Olivera
AU  - Todorović Marković, Biljana
PY  - 2020
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3621
AB  - Due to the low consumption of chemicals, the absence of toxic residual side products, the procedure simplicity and time-saving aspects, gamma irradiation offers advantages over the classical chemical protocols. We successfully employed gamma irradiation in order to introduce N-atoms in Graphene Quantum Dots (GQDs). By irradiating GQDs water dispersions in the presence of isopropyl alcohol and ethylenediamine, at doses of 25, 50 and 200 kGy, we attached amino groups onto GQDs in a single synthetic step. At the same time, a chemical reduction is achieved, too. Selected conditions induced incorporation of N-atoms within GDQs atomic lattice (around 3 at%), at all applied doses. Additionally, the C-atoms percentage was highly increased, from 63 to 79 at % or higher. The zeta potential of dots changed from −34.6 to +9.1 mV, due to the modification of functionalizing groups localized at the surface. Produced chemical changes lead to the desired alteration of the GQDs optical properties, such as an increased photoluminescence intensity, a higher photoluminescence quantum yields (from 2.07 to 18.40%) and a narrowing of the spectral features in the emission spectra. The ability of gamma-irradiated GQDs to quench free radical species was investigated and positively assessed; additionally, non-enzymatic optical detection of Cu(II) ions using GQDs as a sensor was studied and the detection limits areherein reported. These results suggest that GQDs can be potentially applied as smart photoluminescent sensors for metal cations.
PB  - Elsevier
T2  - Ceramics International
T1  - Gamma irradiation of graphene quantum dots with ethylenediamine: Antioxidant for ion sensing
VL  - 46
IS  - 15
SP  - 23611
EP  - 23622
DO  - 10.1016/j.ceramint.2020.06.133
ER  - 

@article{
author = "Jovanović, Svetlana and Dorontić, Slađana and Jovanović, Dragana and Ciasca, Gabriele and Budimir, Milica and Bonasera, Aurelio and Scopelliti, Michelangelo and Marković, Olivera and Todorović Marković, Biljana",
year = "2020",
abstract = "Due to the low consumption of chemicals, the absence of toxic residual side products, the procedure simplicity and time-saving aspects, gamma irradiation offers advantages over the classical chemical protocols. We successfully employed gamma irradiation in order to introduce N-atoms in Graphene Quantum Dots (GQDs). By irradiating GQDs water dispersions in the presence of isopropyl alcohol and ethylenediamine, at doses of 25, 50 and 200 kGy, we attached amino groups onto GQDs in a single synthetic step. At the same time, a chemical reduction is achieved, too. Selected conditions induced incorporation of N-atoms within GDQs atomic lattice (around 3 at%), at all applied doses. Additionally, the C-atoms percentage was highly increased, from 63 to 79 at % or higher. The zeta potential of dots changed from −34.6 to +9.1 mV, due to the modification of functionalizing groups localized at the surface. Produced chemical changes lead to the desired alteration of the GQDs optical properties, such as an increased photoluminescence intensity, a higher photoluminescence quantum yields (from 2.07 to 18.40%) and a narrowing of the spectral features in the emission spectra. The ability of gamma-irradiated GQDs to quench free radical species was investigated and positively assessed; additionally, non-enzymatic optical detection of Cu(II) ions using GQDs as a sensor was studied and the detection limits areherein reported. These results suggest that GQDs can be potentially applied as smart photoluminescent sensors for metal cations.",
publisher = "Elsevier",
journal = "Ceramics International",
title = "Gamma irradiation of graphene quantum dots with ethylenediamine: Antioxidant for ion sensing",
volume = "46",
number = "15",
pages = "23611-23622",
doi = "10.1016/j.ceramint.2020.06.133"
}

Jovanović, S., Dorontić, S., Jovanović, D., Ciasca, G., Budimir, M., Bonasera, A., Scopelliti, M., Marković, O.,& Todorović Marković, B.. (2020). Gamma irradiation of graphene quantum dots with ethylenediamine: Antioxidant for ion sensing. in Ceramics International
Elsevier., 46(15), 23611-23622.
https://doi.org/10.1016/j.ceramint.2020.06.133

Jovanović S, Dorontić S, Jovanović D, Ciasca G, Budimir M, Bonasera A, Scopelliti M, Marković O, Todorović Marković B. Gamma irradiation of graphene quantum dots with ethylenediamine: Antioxidant for ion sensing. in Ceramics International. 2020;46(15):23611-23622.
doi:10.1016/j.ceramint.2020.06.133 .

Jovanović, Svetlana, Dorontić, Slađana, Jovanović, Dragana, Ciasca, Gabriele, Budimir, Milica, Bonasera, Aurelio, Scopelliti, Michelangelo, Marković, Olivera, Todorović Marković, Biljana, "Gamma irradiation of graphene quantum dots with ethylenediamine: Antioxidant for ion sensing" in Ceramics International, 46, no. 15 (2020):23611-23622,
https://doi.org/10.1016/j.ceramint.2020.06.133 . .

TY  - CONF
AU  - Dorontić, Slađana
AU  - Marković, Olivera
AU  - Bonasera, Aurelio
AU  - Jovanović, Svetlana
PY  - 2020
UR  - http://www2.sci.u-szeged.hu/isaep/index.htm
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3849
AB  - Graphene Quantum Dots (GQDs) were produced using electrochemical oxidation of graphite rods. Obtained GQDs were gamma-irradiated in the presence of the N atoms source, ethylenediamine. Both structural and morphological changes were investigated using UV-Vis, X-ray photoelectron and photoluminescence (PL) spectroscopy as well as atomic force microscopy. The ability of both types of dots to change PL intensity in the presence of pesticides such as malathion and glyphosate, as well as copper (II) ions was detected. These preliminary results indicated a high potential of produced GQDs to be applied as non-enzymatic PL sensors for the detection of selected pesticides and metal ions.
PB  - Szeged : University of Szeged
C3  - Proceedings of the 26th International Symposium on Analytical and Environmental Problems, Szeged, Hungary
T1  - Application of graphene quantum dots in heavy metals and pesticides detection
SP  - 179
EP  - 182
UR  - https://hdl.handle.net/21.15107/rcub_cer_3849
ER  - 

@conference{
author = "Dorontić, Slađana and Marković, Olivera and Bonasera, Aurelio and Jovanović, Svetlana",
year = "2020",
abstract = "Graphene Quantum Dots (GQDs) were produced using electrochemical oxidation of graphite rods. Obtained GQDs were gamma-irradiated in the presence of the N atoms source, ethylenediamine. Both structural and morphological changes were investigated using UV-Vis, X-ray photoelectron and photoluminescence (PL) spectroscopy as well as atomic force microscopy. The ability of both types of dots to change PL intensity in the presence of pesticides such as malathion and glyphosate, as well as copper (II) ions was detected. These preliminary results indicated a high potential of produced GQDs to be applied as non-enzymatic PL sensors for the detection of selected pesticides and metal ions.",
publisher = "Szeged : University of Szeged",
journal = "Proceedings of the 26th International Symposium on Analytical and Environmental Problems, Szeged, Hungary",
title = "Application of graphene quantum dots in heavy metals and pesticides detection",
pages = "179-182",
url = "https://hdl.handle.net/21.15107/rcub_cer_3849"
}

Dorontić, S., Marković, O., Bonasera, A.,& Jovanović, S.. (2020). Application of graphene quantum dots in heavy metals and pesticides detection. in Proceedings of the 26th International Symposium on Analytical and Environmental Problems, Szeged, Hungary
Szeged : University of Szeged., 179-182.
https://hdl.handle.net/21.15107/rcub_cer_3849

Dorontić S, Marković O, Bonasera A, Jovanović S. Application of graphene quantum dots in heavy metals and pesticides detection. in Proceedings of the 26th International Symposium on Analytical and Environmental Problems, Szeged, Hungary. 2020;:179-182.
https://hdl.handle.net/21.15107/rcub_cer_3849 .

Dorontić, Slađana, Marković, Olivera, Bonasera, Aurelio, Jovanović, Svetlana, "Application of graphene quantum dots in heavy metals and pesticides detection" in Proceedings of the 26th International Symposium on Analytical and Environmental Problems, Szeged, Hungary (2020):179-182,
https://hdl.handle.net/21.15107/rcub_cer_3849 .