TY  - CONF
AU  - Stanković, Ana
AU  - Drvenica, Ivana
AU  - Đukić-Vuković, Aleksandra
AU  - Marković, Smilja
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4167
AB  - Owing to a wide band gap energy (3.37 eV at RT) and a large exciton binding energy (60 meV), ZnO nanoparticles (ZnONP) have a diverse application, e.g. in electronics, optoelectronics, photocatalysis. Besides, ZnONP have a great potential in medicine for bioimaging, drug/gene delivery or as antimicrobial and anticancer agents. One of suggested governing mechanisms of the mentioned biological activities of ZnONP is based on formation of reactive oxygen species (ROS). When ZnONP absorb photon with energy equal or greater than its band gap, electrons are excited from the valence band (VB) to the conduction band (CB) leaving the holes in VB. Furthermore, the photogenerated holes (h+) and electrons (e-) migrate from bulk to surface. The photogenerated holes at the VB react with water molecules adsorbed at the particle surface to produce hydroxyl radical, while electrons in CB react with oxygen molecules generating anionic superoxide radical O2 -•. Superoxide radicals can be transformed in highly reactive OH• and so on [1]. Derivatives of this active oxygen can damage the bacterial/tumor cells [2]. However, in sufficiency ROS can damage normal cells as well. Thus, an understanding of ZnONP crystal structure-activity relationship and mechanism of ZnONP-related products formation and their consequent activity is crucial for the design of safe ZnONP based biomaterial for application in treating diseases like cancer. A series of ZnONP samples were synthesized by microwave processing of precipitate in the presence of a small amount (5 wt.%) of surfactants CTAB and citric acid. The particles crystallinity and purity were investigated by X-ray diffraction, Raman and ATR-FTIR spectroscopy. The particles morphology and texture properties were observed with field emission scanning electron microscopy (FE–SEM) and nitrogen adsorption–desorption isotherm, respectively. The optical properties were studied using UV–Vis diffuse reflectance and photoluminescence (PL) spectroscopy. ZnONP samples with different surface-to-bulk defect ratio were examined on ROS formation and antimicrobial activity. Future studies will be conducted with an aim to correlate surface-to-bulk defect ratio in ZnONP with mechanism of ROS formation and their cytotoxicity to normal and cancerous cells.
C3  - Book of Abstracts / First CA17140 COST Conference Cancer Nanomedicine – from the Bench to the Bedsid
T1  - Surfactant-Assisted Microwave Processed ZnO Nanoparticles with Optimized Surface-to-Bulk Defect Ratio For Potential Biomedical Application
EP  - 93
SP  - 93
UR  - https://hdl.handle.net/21.15107/rcub_technorep_4167
ER  - 

@conference{
author = "Stanković, Ana and Drvenica, Ivana and Đukić-Vuković, Aleksandra and Marković, Smilja",
year = "2019",
abstract = "Owing to a wide band gap energy (3.37 eV at RT) and a large exciton binding energy (60 meV), ZnO nanoparticles (ZnONP) have a diverse application, e.g. in electronics, optoelectronics, photocatalysis. Besides, ZnONP have a great potential in medicine for bioimaging, drug/gene delivery or as antimicrobial and anticancer agents. One of suggested governing mechanisms of the mentioned biological activities of ZnONP is based on formation of reactive oxygen species (ROS). When ZnONP absorb photon with energy equal or greater than its band gap, electrons are excited from the valence band (VB) to the conduction band (CB) leaving the holes in VB. Furthermore, the photogenerated holes (h+) and electrons (e-) migrate from bulk to surface. The photogenerated holes at the VB react with water molecules adsorbed at the particle surface to produce hydroxyl radical, while electrons in CB react with oxygen molecules generating anionic superoxide radical O2 -•. Superoxide radicals can be transformed in highly reactive OH• and so on [1]. Derivatives of this active oxygen can damage the bacterial/tumor cells [2]. However, in sufficiency ROS can damage normal cells as well. Thus, an understanding of ZnONP crystal structure-activity relationship and mechanism of ZnONP-related products formation and their consequent activity is crucial for the design of safe ZnONP based biomaterial for application in treating diseases like cancer. A series of ZnONP samples were synthesized by microwave processing of precipitate in the presence of a small amount (5 wt.%) of surfactants CTAB and citric acid. The particles crystallinity and purity were investigated by X-ray diffraction, Raman and ATR-FTIR spectroscopy. The particles morphology and texture properties were observed with field emission scanning electron microscopy (FE–SEM) and nitrogen adsorption–desorption isotherm, respectively. The optical properties were studied using UV–Vis diffuse reflectance and photoluminescence (PL) spectroscopy. ZnONP samples with different surface-to-bulk defect ratio were examined on ROS formation and antimicrobial activity. Future studies will be conducted with an aim to correlate surface-to-bulk defect ratio in ZnONP with mechanism of ROS formation and their cytotoxicity to normal and cancerous cells.",
journal = "Book of Abstracts / First CA17140 COST Conference Cancer Nanomedicine – from the Bench to the Bedsid",
title = "Surfactant-Assisted Microwave Processed ZnO Nanoparticles with Optimized Surface-to-Bulk Defect Ratio For Potential Biomedical Application",
pages = "93-93",
url = "https://hdl.handle.net/21.15107/rcub_technorep_4167"
}

Stanković, A., Drvenica, I., Đukić-Vuković, A.,& Marković, S.. (2019). Surfactant-Assisted Microwave Processed ZnO Nanoparticles with Optimized Surface-to-Bulk Defect Ratio For Potential Biomedical Application. in Book of Abstracts / First CA17140 COST Conference Cancer Nanomedicine – from the Bench to the Bedsid, 93-93.
https://hdl.handle.net/21.15107/rcub_technorep_4167

Stanković A, Drvenica I, Đukić-Vuković A, Marković S. Surfactant-Assisted Microwave Processed ZnO Nanoparticles with Optimized Surface-to-Bulk Defect Ratio For Potential Biomedical Application. in Book of Abstracts / First CA17140 COST Conference Cancer Nanomedicine – from the Bench to the Bedsid. 2019;:93-93.
https://hdl.handle.net/21.15107/rcub_technorep_4167 .

Stanković, Ana, Drvenica, Ivana, Đukić-Vuković, Aleksandra, Marković, Smilja, "Surfactant-Assisted Microwave Processed ZnO Nanoparticles with Optimized Surface-to-Bulk Defect Ratio For Potential Biomedical Application" in Book of Abstracts / First CA17140 COST Conference Cancer Nanomedicine – from the Bench to the Bedsid (2019):93-93,
https://hdl.handle.net/21.15107/rcub_technorep_4167 .

TY  - JOUR
AU  - Marković, Smilja
AU  - Stanković, Ana
AU  - Dostanić, Jasmina
AU  - Veselinović, Ljiljana
AU  - Mančić, Lidija
AU  - Škapin, Srečo Davor
AU  - Dražić, Goran
AU  - Janković-Častvan, Ivona
AU  - Uskoković, Dragan
PY  - 2017
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3541
AB  - Mechanical milling of commercial ZnO and SnO2 was used to produce a ZnO/SnO2 composite with a high density of surface defects; in particular, zinc interstitials (Zni) and oxygen vacancies (VO). To determine the impact of surface defects on photocatalytic activity, the relative concentration ratio of bulk defects to surface defects was modified by annealing at 400 and 700 degrees C. The possible application of the ZnO/SnO2 composite as a natural sunlight and UV- light driven photocatalyst was revealed via de-colorization of methylene blue. In both cases the ZnO/SnO2 composite exhibited enhanced photocatalytic activity as compared to the pristine ZnO. In order to investigate the origin of the enhancement, the pristine metal oxides and composites were characterized using a variety of techniques, including X-ray diffraction (XRD), Raman and Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), laser diffraction particle size analysis, Brunauer-Emmett-Teller, UV-Vis diffuse reflectance and photoluminescence spectroscopy. High-resolution transmission electron microscopy (HRTEM) and elemental mapping analyses were used to reveal the presence of SnO2 nanocrystallites on the surface of larger ZnO particles. The enhanced photocatalytic activity of the composite can be attributed to the synergetic effect of the surface defects and the ZnO/SnO2 heterojunction particles, which facilitated charge separation, thereby hindering the recombination of photogenerated carriers. This study draws attention to mechanical activation as an inexpensive and environmentally friendly technique for the large-scale production of the composite with an enhanced photocatalytic activity under illumination of either UV or sunlight.
PB  - Royal Soc Chemistry, Cambridge
T2  - RSC Advances
T1  - Simultaneous enhancement of natural sunlightand artificial UV-driven photocatalytic activity of a mechanically activated ZnO/SnO2 composite
EP  - 42737
IS  - 68
SP  - 42725
VL  - 7
DO  - 10.1039/c7ra06895f
ER  - 

@article{
author = "Marković, Smilja and Stanković, Ana and Dostanić, Jasmina and Veselinović, Ljiljana and Mančić, Lidija and Škapin, Srečo Davor and Dražić, Goran and Janković-Častvan, Ivona and Uskoković, Dragan",
year = "2017",
abstract = "Mechanical milling of commercial ZnO and SnO2 was used to produce a ZnO/SnO2 composite with a high density of surface defects; in particular, zinc interstitials (Zni) and oxygen vacancies (VO). To determine the impact of surface defects on photocatalytic activity, the relative concentration ratio of bulk defects to surface defects was modified by annealing at 400 and 700 degrees C. The possible application of the ZnO/SnO2 composite as a natural sunlight and UV- light driven photocatalyst was revealed via de-colorization of methylene blue. In both cases the ZnO/SnO2 composite exhibited enhanced photocatalytic activity as compared to the pristine ZnO. In order to investigate the origin of the enhancement, the pristine metal oxides and composites were characterized using a variety of techniques, including X-ray diffraction (XRD), Raman and Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), laser diffraction particle size analysis, Brunauer-Emmett-Teller, UV-Vis diffuse reflectance and photoluminescence spectroscopy. High-resolution transmission electron microscopy (HRTEM) and elemental mapping analyses were used to reveal the presence of SnO2 nanocrystallites on the surface of larger ZnO particles. The enhanced photocatalytic activity of the composite can be attributed to the synergetic effect of the surface defects and the ZnO/SnO2 heterojunction particles, which facilitated charge separation, thereby hindering the recombination of photogenerated carriers. This study draws attention to mechanical activation as an inexpensive and environmentally friendly technique for the large-scale production of the composite with an enhanced photocatalytic activity under illumination of either UV or sunlight.",
publisher = "Royal Soc Chemistry, Cambridge",
journal = "RSC Advances",
title = "Simultaneous enhancement of natural sunlightand artificial UV-driven photocatalytic activity of a mechanically activated ZnO/SnO2 composite",
pages = "42737-42725",
number = "68",
volume = "7",
doi = "10.1039/c7ra06895f"
}

Marković, S., Stanković, A., Dostanić, J., Veselinović, L., Mančić, L., Škapin, S. D., Dražić, G., Janković-Častvan, I.,& Uskoković, D.. (2017). Simultaneous enhancement of natural sunlightand artificial UV-driven photocatalytic activity of a mechanically activated ZnO/SnO2 composite. in RSC Advances
Royal Soc Chemistry, Cambridge., 7(68), 42725-42737.
https://doi.org/10.1039/c7ra06895f

Marković S, Stanković A, Dostanić J, Veselinović L, Mančić L, Škapin SD, Dražić G, Janković-Častvan I, Uskoković D. Simultaneous enhancement of natural sunlightand artificial UV-driven photocatalytic activity of a mechanically activated ZnO/SnO2 composite. in RSC Advances. 2017;7(68):42725-42737.
doi:10.1039/c7ra06895f .

Marković, Smilja, Stanković, Ana, Dostanić, Jasmina, Veselinović, Ljiljana, Mančić, Lidija, Škapin, Srečo Davor, Dražić, Goran, Janković-Častvan, Ivona, Uskoković, Dragan, "Simultaneous enhancement of natural sunlightand artificial UV-driven photocatalytic activity of a mechanically activated ZnO/SnO2 composite" in RSC Advances, 7, no. 68 (2017):42725-42737,
https://doi.org/10.1039/c7ra06895f . .

TY  - JOUR
AU  - Marković, Smilja
AU  - Stanković, Ana
AU  - Lopičić, Zorica
AU  - Lazarević, Slavica
AU  - Stojanović, Mirjana
AU  - Uskoković, Dragan
PY  - 2015
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2918
AB  - A possibility to apply raw, powdered peach shells ( PS) as a biosorbent for water purification was studied. The PSs are locally available as a solid waste in a fruit juice factory; methylene blue (MB) was chosen as representative of common pollutants in textile industry wastewater. The phase composition of prepared particles was identified by XRD. The particle morphology was characterized by FE-SEM, while the size distribution was measured by a laser light-scattering particle size analyzer. The BET specific surface area was determined from N-2 adsorption/desorption experiments. The effect of operating parameters: the biosorbent amount (50-1000 mg/100 mL), contact time (10-180 min), solution pH (2-12) and initial concentration (10-100 ppm) on biosorption efficiency was examined. Optimal conditions for MB removal were found to be: the biosorbent amount of 400 mg/100 mL and pH 5.5. A high efficiency of MB removal was established after 180 min: 99% for [MB](i) = 10 ppm and 76% for [MB](i) = 100 ppm. Biosorption is well described by the Freundlich- and BET-type isotherms, implicating heterogeneous adsorption sites and interconnections between adsorbed molecules. The FTIR spectroscopy results indicate hydrogen bonding between the dye and the biomass. The obtained results shown that raw peach shell particles could be used as an efficient low-cost biosorbent for dye removal from water.
PB  - Elsevier Sci Ltd, Oxford
T2  - Journal of Environmental Chemical Engineering
T1  - Application of raw peach shell particles for removal of methylene blue
EP  - 724
IS  - 2
SP  - 716
VL  - 3
DO  - 10.1016/j.jece.2015.04.002
ER  - 

@article{
author = "Marković, Smilja and Stanković, Ana and Lopičić, Zorica and Lazarević, Slavica and Stojanović, Mirjana and Uskoković, Dragan",
year = "2015",
abstract = "A possibility to apply raw, powdered peach shells ( PS) as a biosorbent for water purification was studied. The PSs are locally available as a solid waste in a fruit juice factory; methylene blue (MB) was chosen as representative of common pollutants in textile industry wastewater. The phase composition of prepared particles was identified by XRD. The particle morphology was characterized by FE-SEM, while the size distribution was measured by a laser light-scattering particle size analyzer. The BET specific surface area was determined from N-2 adsorption/desorption experiments. The effect of operating parameters: the biosorbent amount (50-1000 mg/100 mL), contact time (10-180 min), solution pH (2-12) and initial concentration (10-100 ppm) on biosorption efficiency was examined. Optimal conditions for MB removal were found to be: the biosorbent amount of 400 mg/100 mL and pH 5.5. A high efficiency of MB removal was established after 180 min: 99% for [MB](i) = 10 ppm and 76% for [MB](i) = 100 ppm. Biosorption is well described by the Freundlich- and BET-type isotherms, implicating heterogeneous adsorption sites and interconnections between adsorbed molecules. The FTIR spectroscopy results indicate hydrogen bonding between the dye and the biomass. The obtained results shown that raw peach shell particles could be used as an efficient low-cost biosorbent for dye removal from water.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Journal of Environmental Chemical Engineering",
title = "Application of raw peach shell particles for removal of methylene blue",
pages = "724-716",
number = "2",
volume = "3",
doi = "10.1016/j.jece.2015.04.002"
}

Marković, S., Stanković, A., Lopičić, Z., Lazarević, S., Stojanović, M.,& Uskoković, D.. (2015). Application of raw peach shell particles for removal of methylene blue. in Journal of Environmental Chemical Engineering
Elsevier Sci Ltd, Oxford., 3(2), 716-724.
https://doi.org/10.1016/j.jece.2015.04.002

Marković S, Stanković A, Lopičić Z, Lazarević S, Stojanović M, Uskoković D. Application of raw peach shell particles for removal of methylene blue. in Journal of Environmental Chemical Engineering. 2015;3(2):716-724.
doi:10.1016/j.jece.2015.04.002 .

Marković, Smilja, Stanković, Ana, Lopičić, Zorica, Lazarević, Slavica, Stojanović, Mirjana, Uskoković, Dragan, "Application of raw peach shell particles for removal of methylene blue" in Journal of Environmental Chemical Engineering, 3, no. 2 (2015):716-724,
https://doi.org/10.1016/j.jece.2015.04.002 . .

TY  - JOUR
AU  - Stanković, Ana
AU  - Dimitrijević, Suzana
AU  - Uskoković, Dragan
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2480
AB  - Metal oxide nanoparticles represent a new class of important materials that are increasingly being developed for use in research and health-related applications. Although the antibacterial activity and efficiency of bulk zinc oxide were investigated in vitro, the knowledge about the antibacterial activity of ZnO nanoparticles remains deficient. In this study, we have synthesized ZnO particles of different sizes and morphologies with the assistance of different types of surface stabilizing agents - polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA) and poly (alpha,gamma, L-glutamic acid) (PGA) - through a low-temperature hydrothermal procedure. The characterization of the prepared powders was preformed using X-ray diffraction (XRD) method and field emission scanning electron microscopy (FE SEM), as well as Malvern's Mastersizer instrument for particle size distribution. The specific surface area (SSA) of the ZnO powders was measured by standard Brunauer-Emmett-Teller (BET) technique. The antibacterial behavior of the synthesized ZnO particles was tested against gram-negative and gram-positive bacterial cultures, namely Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively. We compared the results of the antibacterial properties of the synthesized ZnO samples with those of the commercial ZnO powder. According to the obtained results, the highest microbial cell reduction rate was recorded for the synthesized ZnO powder consisting of nanospherical particles. In all of the examined samples. ZnO particles demonstrated a significant bacteriostatic activity.
PB  - Elsevier Science Bv, Amsterdam
T2  - Colloids and Surfaces B-Biointerfaces
T1  - Influence of size scale and morphology on antibacterial properties of ZnO powders hydrothemally synthesized using different surface stabilizing agents
EP  - 28
SP  - 21
VL  - 102
DO  - 10.1016/j.colsurfb.2012.07.033
ER  - 

@article{
author = "Stanković, Ana and Dimitrijević, Suzana and Uskoković, Dragan",
year = "2013",
abstract = "Metal oxide nanoparticles represent a new class of important materials that are increasingly being developed for use in research and health-related applications. Although the antibacterial activity and efficiency of bulk zinc oxide were investigated in vitro, the knowledge about the antibacterial activity of ZnO nanoparticles remains deficient. In this study, we have synthesized ZnO particles of different sizes and morphologies with the assistance of different types of surface stabilizing agents - polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA) and poly (alpha,gamma, L-glutamic acid) (PGA) - through a low-temperature hydrothermal procedure. The characterization of the prepared powders was preformed using X-ray diffraction (XRD) method and field emission scanning electron microscopy (FE SEM), as well as Malvern's Mastersizer instrument for particle size distribution. The specific surface area (SSA) of the ZnO powders was measured by standard Brunauer-Emmett-Teller (BET) technique. The antibacterial behavior of the synthesized ZnO particles was tested against gram-negative and gram-positive bacterial cultures, namely Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively. We compared the results of the antibacterial properties of the synthesized ZnO samples with those of the commercial ZnO powder. According to the obtained results, the highest microbial cell reduction rate was recorded for the synthesized ZnO powder consisting of nanospherical particles. In all of the examined samples. ZnO particles demonstrated a significant bacteriostatic activity.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Colloids and Surfaces B-Biointerfaces",
title = "Influence of size scale and morphology on antibacterial properties of ZnO powders hydrothemally synthesized using different surface stabilizing agents",
pages = "28-21",
volume = "102",
doi = "10.1016/j.colsurfb.2012.07.033"
}

Stanković, A., Dimitrijević, S.,& Uskoković, D.. (2013). Influence of size scale and morphology on antibacterial properties of ZnO powders hydrothemally synthesized using different surface stabilizing agents. in Colloids and Surfaces B-Biointerfaces
Elsevier Science Bv, Amsterdam., 102, 21-28.
https://doi.org/10.1016/j.colsurfb.2012.07.033

Stanković A, Dimitrijević S, Uskoković D. Influence of size scale and morphology on antibacterial properties of ZnO powders hydrothemally synthesized using different surface stabilizing agents. in Colloids and Surfaces B-Biointerfaces. 2013;102:21-28.
doi:10.1016/j.colsurfb.2012.07.033 .

Stanković, Ana, Dimitrijević, Suzana, Uskoković, Dragan, "Influence of size scale and morphology on antibacterial properties of ZnO powders hydrothemally synthesized using different surface stabilizing agents" in Colloids and Surfaces B-Biointerfaces, 102 (2013):21-28,
https://doi.org/10.1016/j.colsurfb.2012.07.033 . .