TY  - JOUR
AU  - Đurđić, Slađana
AU  - Vlahović, Filip
AU  - Ognjanović, Miloš
AU  - Gemeiner, Pavol
AU  - Sarakhman, Olha
AU  - Stanković, Vesna
AU  - Mutić, Jelena
AU  - Stanković, Dalibor
AU  - Švorc, Lubomír
PY  - 2024
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12205
AB  - In the present work, a nanocomposite, based on embedding Co-doped CeO2 nanoparticles into graphitic carbon nitride (g-C3N4), was applied to functionalize commercial glassy carbon paste. This is the first application of the electrochemical sensor, developed through the proposed procedure, in electrochemical sensing. The sensor was utilized for the electrochemical determination of organophosphate pesticide fenitrothion (FNT). Cyclic voltammetry identified reversible oxidation of FNT (oxidation at 0.18 V and reduction at 0.13 V) and additional reduction at 0.62 V vs. Ag/AgCl in HCl solution (pH =1). Theoretical calculations were carried out to model and elucidate experimentally observed redox processes. Special attention was devoted to modeling experimental conditions, and based on the obtained results, a detailed redox mechanism of the investigated analyte was proposed. This represents the first complete and unambiguous elucidation of the FNT redox mechanism, supported by joined experimental and theoretical data. Square wave voltammetry (SWV) was utilized for quantification, whereby the FNT oxidation peak was chosen for monitoring the analyte concentration. The developed sensor provided a nanomolar detection limit (3.2 nmol L 1), a wide linear concentration range (from 0.01 to 13.7 μmol L 1), and good precision, repeatability, and selectivity towards FNT. Practical application possibility was explored by testing the sensor performance for examining tap water and apple samples. Recovery tests, conducted during the FNT-spiked sample assays, showed a great application capability of the developed sensor for real-time monitoring of FNT traces in environmental samples.
T2  - Science of The Total Environment
T1  - Nano-size cobalt-doped cerium oxide particles embedded into graphitic carbon nitride for enhanced electrochemical sensing of insecticide fenitrothion in environmental samples: An experimental study with the theoretical elucidation of redox events
VL  - 909
SP  - 168483
DO  - 10.1016/j.scitotenv.2023.168483
ER  - 

@article{
author = "Đurđić, Slađana and Vlahović, Filip and Ognjanović, Miloš and Gemeiner, Pavol and Sarakhman, Olha and Stanković, Vesna and Mutić, Jelena and Stanković, Dalibor and Švorc, Lubomír",
year = "2024",
abstract = "In the present work, a nanocomposite, based on embedding Co-doped CeO2 nanoparticles into graphitic carbon nitride (g-C3N4), was applied to functionalize commercial glassy carbon paste. This is the first application of the electrochemical sensor, developed through the proposed procedure, in electrochemical sensing. The sensor was utilized for the electrochemical determination of organophosphate pesticide fenitrothion (FNT). Cyclic voltammetry identified reversible oxidation of FNT (oxidation at 0.18 V and reduction at 0.13 V) and additional reduction at 0.62 V vs. Ag/AgCl in HCl solution (pH =1). Theoretical calculations were carried out to model and elucidate experimentally observed redox processes. Special attention was devoted to modeling experimental conditions, and based on the obtained results, a detailed redox mechanism of the investigated analyte was proposed. This represents the first complete and unambiguous elucidation of the FNT redox mechanism, supported by joined experimental and theoretical data. Square wave voltammetry (SWV) was utilized for quantification, whereby the FNT oxidation peak was chosen for monitoring the analyte concentration. The developed sensor provided a nanomolar detection limit (3.2 nmol L 1), a wide linear concentration range (from 0.01 to 13.7 μmol L 1), and good precision, repeatability, and selectivity towards FNT. Practical application possibility was explored by testing the sensor performance for examining tap water and apple samples. Recovery tests, conducted during the FNT-spiked sample assays, showed a great application capability of the developed sensor for real-time monitoring of FNT traces in environmental samples.",
journal = "Science of The Total Environment",
title = "Nano-size cobalt-doped cerium oxide particles embedded into graphitic carbon nitride for enhanced electrochemical sensing of insecticide fenitrothion in environmental samples: An experimental study with the theoretical elucidation of redox events",
volume = "909",
pages = "168483",
doi = "10.1016/j.scitotenv.2023.168483"
}

Đurđić, S., Vlahović, F., Ognjanović, M., Gemeiner, P., Sarakhman, O., Stanković, V., Mutić, J., Stanković, D.,& Švorc, L.. (2024). Nano-size cobalt-doped cerium oxide particles embedded into graphitic carbon nitride for enhanced electrochemical sensing of insecticide fenitrothion in environmental samples: An experimental study with the theoretical elucidation of redox events. in Science of The Total Environment, 909, 168483.
https://doi.org/10.1016/j.scitotenv.2023.168483

Đurđić S, Vlahović F, Ognjanović M, Gemeiner P, Sarakhman O, Stanković V, Mutić J, Stanković D, Švorc L. Nano-size cobalt-doped cerium oxide particles embedded into graphitic carbon nitride for enhanced electrochemical sensing of insecticide fenitrothion in environmental samples: An experimental study with the theoretical elucidation of redox events. in Science of The Total Environment. 2024;909:168483.
doi:10.1016/j.scitotenv.2023.168483 .

Đurđić, Slađana, Vlahović, Filip, Ognjanović, Miloš, Gemeiner, Pavol, Sarakhman, Olha, Stanković, Vesna, Mutić, Jelena, Stanković, Dalibor, Švorc, Lubomír, "Nano-size cobalt-doped cerium oxide particles embedded into graphitic carbon nitride for enhanced electrochemical sensing of insecticide fenitrothion in environmental samples: An experimental study with the theoretical elucidation of redox events" in Science of The Total Environment, 909 (2024):168483,
https://doi.org/10.1016/j.scitotenv.2023.168483 . .

TY  - JOUR
AU  - Haššo, Marek
AU  - Sarakhman, Olha
AU  - Đurđić, Slađana
AU  - Stanković, Dalibor M.
AU  - Švorc, Lubomir
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11089
AB  - In this work, an advanced electrochemical platform was developed for the simple, rapid and sensitive determination of the polyphenolic compound tannic acid in various beverages using the combination of batch injection analysis with amperometric detection on a screen-printed carbon electrode. Several experimental parameters (pH of supporting electrolyte, detection potential, dispensing rate, injected volume, stirring) were consistently evaluated. The most favorable analytical performance in terms of sensitivity, selectivity, repeatability and sampling frequency was obtained in Britton-Robinson buffer pH 5.0 at a detection potential of +0.6 V vs. Ag/AgCl, a dispensing rate of 204 µL/s and an injected volume of 80 µL under stirring condition (1500 r.p.m.). The presented platform has advantages for routine analysis including portable and small-scale experimental setup, low sample consumption (∼100 µL), simple sample preparation (dilution in supporting electrolyte), high sampling frequency (180 injections per hour), low limit of detection (80 nM) and suitable precision (RSD = 4.2% for 10 μM tannic acid, n = 20). The applicability of the method was verified by analyzing several beverage samples (tea, wine) in spike-recovery assay with the recovery values for tannic acid ranging from 94 to 101 %. © 2023 Elsevier B.V.
T2  - Journal of Electroanalytical Chemistry
T1  - Advanced electrochemical platform for simple and rapid quantification of tannic acid in beverages using batch injection analysis with amperometric detection
VL  - 942
SP  - 117578
DO  - 10.1016/j.jelechem.2023.117578
ER  - 

@article{
author = "Haššo, Marek and Sarakhman, Olha and Đurđić, Slađana and Stanković, Dalibor M. and Švorc, Lubomir",
year = "2023",
abstract = "In this work, an advanced electrochemical platform was developed for the simple, rapid and sensitive determination of the polyphenolic compound tannic acid in various beverages using the combination of batch injection analysis with amperometric detection on a screen-printed carbon electrode. Several experimental parameters (pH of supporting electrolyte, detection potential, dispensing rate, injected volume, stirring) were consistently evaluated. The most favorable analytical performance in terms of sensitivity, selectivity, repeatability and sampling frequency was obtained in Britton-Robinson buffer pH 5.0 at a detection potential of +0.6 V vs. Ag/AgCl, a dispensing rate of 204 µL/s and an injected volume of 80 µL under stirring condition (1500 r.p.m.). The presented platform has advantages for routine analysis including portable and small-scale experimental setup, low sample consumption (∼100 µL), simple sample preparation (dilution in supporting electrolyte), high sampling frequency (180 injections per hour), low limit of detection (80 nM) and suitable precision (RSD = 4.2% for 10 μM tannic acid, n = 20). The applicability of the method was verified by analyzing several beverage samples (tea, wine) in spike-recovery assay with the recovery values for tannic acid ranging from 94 to 101 %. © 2023 Elsevier B.V.",
journal = "Journal of Electroanalytical Chemistry",
title = "Advanced electrochemical platform for simple and rapid quantification of tannic acid in beverages using batch injection analysis with amperometric detection",
volume = "942",
pages = "117578",
doi = "10.1016/j.jelechem.2023.117578"
}

Haššo, M., Sarakhman, O., Đurđić, S., Stanković, D. M.,& Švorc, L.. (2023). Advanced electrochemical platform for simple and rapid quantification of tannic acid in beverages using batch injection analysis with amperometric detection. in Journal of Electroanalytical Chemistry, 942, 117578.
https://doi.org/10.1016/j.jelechem.2023.117578

Haššo M, Sarakhman O, Đurđić S, Stanković DM, Švorc L. Advanced electrochemical platform for simple and rapid quantification of tannic acid in beverages using batch injection analysis with amperometric detection. in Journal of Electroanalytical Chemistry. 2023;942:117578.
doi:10.1016/j.jelechem.2023.117578 .

Haššo, Marek, Sarakhman, Olha, Đurđić, Slađana, Stanković, Dalibor M., Švorc, Lubomir, "Advanced electrochemical platform for simple and rapid quantification of tannic acid in beverages using batch injection analysis with amperometric detection" in Journal of Electroanalytical Chemistry, 942 (2023):117578,
https://doi.org/10.1016/j.jelechem.2023.117578 . .

TY  - JOUR
AU  - Haššo, Marek
AU  - Sarakhman, Olha
AU  - Stanković, Dalibor M.
AU  - Švorc, Lubomir
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9692
AB  - For the first time, we propose a new modification-free voltammetric platform for simple, fast and reliable quantification of the sport performance-enhancing stimulant synephrine (SYN) based on the usage of a commercial screen-printed boron-doped diamond (BDD) electrochemical sensor. Applying cyclic voltammetry, SYN exhibited one well-shaped, irreversible and diffusion-driven oxidation peak at a peak potential of +1.45 V (vs. the silver pseudoreference electrode) in the presence of 2 M HClO4. Under the selected experimental conditions, the following analytical parameters for determination of SYN were obtained: linear concentration ranges from 19.6 up to 1000 μM and from 9.9 up to 1000 μM for differential pulse (DPV) and square-wave voltammetry (SWV), respectively, detection limits at micromolar concentration levels and intra-day repeatability with a relative standard deviation below 4% for both pulse techniques. The interference study revealed fair selectivity when considering the target dietary supplements. The feasibility of the developed voltammetric platform was verified in the analysis of commercially available dietary supplements and reasonable recovery values were achieved by DPV and SWV, respectively. In addition, the method can be performed directly without higher consumption of chemicals, waste generation, complex sample extraction and higher instrumentation cost. The advanced BDD electrochemical sensor has appeared to be a suitable competitor for efficient applications in food quality control analysis.
T2  - Analytical Methods
T1  - A new voltammetric platform for reliable determination of the sport performance-enhancing stimulant synephrine in dietary supplements using a boron-doped diamond electrode
VL  - 12
IS  - 39
SP  - 4749
EP  - 4758
DO  - 10.1039/D0AY01425G
ER  - 

@article{
author = "Haššo, Marek and Sarakhman, Olha and Stanković, Dalibor M. and Švorc, Lubomir",
year = "2020",
abstract = "For the first time, we propose a new modification-free voltammetric platform for simple, fast and reliable quantification of the sport performance-enhancing stimulant synephrine (SYN) based on the usage of a commercial screen-printed boron-doped diamond (BDD) electrochemical sensor. Applying cyclic voltammetry, SYN exhibited one well-shaped, irreversible and diffusion-driven oxidation peak at a peak potential of +1.45 V (vs. the silver pseudoreference electrode) in the presence of 2 M HClO4. Under the selected experimental conditions, the following analytical parameters for determination of SYN were obtained: linear concentration ranges from 19.6 up to 1000 μM and from 9.9 up to 1000 μM for differential pulse (DPV) and square-wave voltammetry (SWV), respectively, detection limits at micromolar concentration levels and intra-day repeatability with a relative standard deviation below 4% for both pulse techniques. The interference study revealed fair selectivity when considering the target dietary supplements. The feasibility of the developed voltammetric platform was verified in the analysis of commercially available dietary supplements and reasonable recovery values were achieved by DPV and SWV, respectively. In addition, the method can be performed directly without higher consumption of chemicals, waste generation, complex sample extraction and higher instrumentation cost. The advanced BDD electrochemical sensor has appeared to be a suitable competitor for efficient applications in food quality control analysis.",
journal = "Analytical Methods",
title = "A new voltammetric platform for reliable determination of the sport performance-enhancing stimulant synephrine in dietary supplements using a boron-doped diamond electrode",
volume = "12",
number = "39",
pages = "4749-4758",
doi = "10.1039/D0AY01425G"
}

Haššo, M., Sarakhman, O., Stanković, D. M.,& Švorc, L.. (2020). A new voltammetric platform for reliable determination of the sport performance-enhancing stimulant synephrine in dietary supplements using a boron-doped diamond electrode. in Analytical Methods, 12(39), 4749-4758.
https://doi.org/10.1039/D0AY01425G

Haššo M, Sarakhman O, Stanković DM, Švorc L. A new voltammetric platform for reliable determination of the sport performance-enhancing stimulant synephrine in dietary supplements using a boron-doped diamond electrode. in Analytical Methods. 2020;12(39):4749-4758.
doi:10.1039/D0AY01425G .

Haššo, Marek, Sarakhman, Olha, Stanković, Dalibor M., Švorc, Lubomir, "A new voltammetric platform for reliable determination of the sport performance-enhancing stimulant synephrine in dietary supplements using a boron-doped diamond electrode" in Analytical Methods, 12, no. 39 (2020):4749-4758,
https://doi.org/10.1039/D0AY01425G . .

TY  - JOUR
AU  - Švorc, Lubomir
AU  - Haššo, Marek
AU  - Sarakhman, Olha
AU  - Kianičkova, Kristina
AU  - Stanković, Dalibor M.
AU  - Otrisal, Pavel
PY  - 2018
UR  - https://linkinghub.elsevier.com/retrieve/pii/S0026265X18307367
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7791
AB  - In the present paper, a miniaturized boron-doped diamond electrode (BDDE) is proposed as a progressive electrochemical sensor for simple, fast and reliable quantification of dimethylxanthine alkaloid, theobromine (TB). Using cyclic voltammetry, the studied xanthine provided one well-shaped, irreversible and diffusion-controlled oxidation peak at relatively high potentials (+1.2 V vs. Ag/AgCl/3 M KCl reference electrode) in the presence of 0.1 M H2SO4. After selection of suitable experimental conditions, the linear calibration curves for TB were obtained in the concentration range from 0.99 up to 54.5 μM with the sensitivity of 0.07 μA/μM providing both differential pulse (DPV) and square-wave voltammetric (SWV) techniques, respectively. The elaborated voltammetric protocol yielded low detection limits of 0.42 and 0.51 μM accompanied by adequate intra-day repeatability (relative standard deviation of 2.5 and 1.7%) using DPV and SWV procedure, respectively. The interference study revealed the reasonable selectivity when taking the target food samples into account. The practical applicability of the voltammetric protocol using a miniaturized BDDE was verified in the analysis of six commercially available brands of chocolate products with the determined mass percentages of TB ranging from 0.75 to 2.24% and from 0.69 to 2.15% using DPV and SWV procedure, respectively. The obtained results were also in a good agreement with those achieved by reference titration method with potentiometric indication. The progressive electrochemical sensor based on a miniaturized BDDE has appeared to be an attractive candidate for practical applications in food quality control. Besides, the proposed voltammetric protocol presents advantages when compared to others techniques (e.g. chromatography), concerning simplicity, cost, speed of analysis, waste generation (environmentally friendly) and samples pretreatment (only dilution in electrolyte solution prior to analysis). © 2018 Elsevier B.V.
T2  - Microchemical Journal
T1  - A progressive electrochemical sensor for food quality control: Reliable determination of theobromine in chocolate products using a miniaturized boron-doped diamond electrode
VL  - 142
SP  - 297
EP  - 304
DO  - 10.1016/j.microc.2018.07.007
ER  - 

@article{
author = "Švorc, Lubomir and Haššo, Marek and Sarakhman, Olha and Kianičkova, Kristina and Stanković, Dalibor M. and Otrisal, Pavel",
year = "2018",
abstract = "In the present paper, a miniaturized boron-doped diamond electrode (BDDE) is proposed as a progressive electrochemical sensor for simple, fast and reliable quantification of dimethylxanthine alkaloid, theobromine (TB). Using cyclic voltammetry, the studied xanthine provided one well-shaped, irreversible and diffusion-controlled oxidation peak at relatively high potentials (+1.2 V vs. Ag/AgCl/3 M KCl reference electrode) in the presence of 0.1 M H2SO4. After selection of suitable experimental conditions, the linear calibration curves for TB were obtained in the concentration range from 0.99 up to 54.5 μM with the sensitivity of 0.07 μA/μM providing both differential pulse (DPV) and square-wave voltammetric (SWV) techniques, respectively. The elaborated voltammetric protocol yielded low detection limits of 0.42 and 0.51 μM accompanied by adequate intra-day repeatability (relative standard deviation of 2.5 and 1.7%) using DPV and SWV procedure, respectively. The interference study revealed the reasonable selectivity when taking the target food samples into account. The practical applicability of the voltammetric protocol using a miniaturized BDDE was verified in the analysis of six commercially available brands of chocolate products with the determined mass percentages of TB ranging from 0.75 to 2.24% and from 0.69 to 2.15% using DPV and SWV procedure, respectively. The obtained results were also in a good agreement with those achieved by reference titration method with potentiometric indication. The progressive electrochemical sensor based on a miniaturized BDDE has appeared to be an attractive candidate for practical applications in food quality control. Besides, the proposed voltammetric protocol presents advantages when compared to others techniques (e.g. chromatography), concerning simplicity, cost, speed of analysis, waste generation (environmentally friendly) and samples pretreatment (only dilution in electrolyte solution prior to analysis). © 2018 Elsevier B.V.",
journal = "Microchemical Journal",
title = "A progressive electrochemical sensor for food quality control: Reliable determination of theobromine in chocolate products using a miniaturized boron-doped diamond electrode",
volume = "142",
pages = "297-304",
doi = "10.1016/j.microc.2018.07.007"
}

Švorc, L., Haššo, M., Sarakhman, O., Kianičkova, K., Stanković, D. M.,& Otrisal, P.. (2018). A progressive electrochemical sensor for food quality control: Reliable determination of theobromine in chocolate products using a miniaturized boron-doped diamond electrode. in Microchemical Journal, 142, 297-304.
https://doi.org/10.1016/j.microc.2018.07.007

Švorc L, Haššo M, Sarakhman O, Kianičkova K, Stanković DM, Otrisal P. A progressive electrochemical sensor for food quality control: Reliable determination of theobromine in chocolate products using a miniaturized boron-doped diamond electrode. in Microchemical Journal. 2018;142:297-304.
doi:10.1016/j.microc.2018.07.007 .

Švorc, Lubomir, Haššo, Marek, Sarakhman, Olha, Kianičkova, Kristina, Stanković, Dalibor M., Otrisal, Pavel, "A progressive electrochemical sensor for food quality control: Reliable determination of theobromine in chocolate products using a miniaturized boron-doped diamond electrode" in Microchemical Journal, 142 (2018):297-304,
https://doi.org/10.1016/j.microc.2018.07.007 . .