TY  - JOUR
AU  - Cinkova, Kristina
AU  - Kianičkova, Kristina
AU  - Stanković, Dalibor M.
AU  - Vojs, Marian
AU  - Marton, Marian
AU  - Švorc, Lubomir
PY  - 2018
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7662
AB  - In this work, the electrochemical oxidation and subsequent determination of uric acid was investigated using boron-doped diamond electrodes with various B/C ratios (0-2000 ppm). The cyclic voltammetric study showed one irreversible oxidation peak at +(1.1-1.25) V (vs. Ag/AgCl/3 M KCl) in the presence of Britton-Robinson buffer (pH 2.25) depending on the boron content. Employing differential pulse voltammetry using the 2000 ppm boron-doped diamond electrode the acquired analytical parameters were as follows: a limit of detection of 7.7 M, a limit of quantification of 26 M and intra-day repeatability (relative standard deviation of 2.9% for n = 15). After performing an interference study, the method was applied to the determination of uric acid in biological samples (human urine). The uric acid concentrations determined in the urine samples were compared with the reference values stated in the literature. The proposed methodology using boron-doped diamond electrodes could find applications in uric acid sensing within clinical, pharmaceutical and environmental analysis.
T2  - Analytical Methods
T1  - The doping level of boron-doped diamond electrodes affects the voltammetric sensing of uric acid
VL  - 10
IS  - 9
SP  - 991
EP  - 996
DO  - 10.1039/C7AY02720F
ER  - 

@article{
author = "Cinkova, Kristina and Kianičkova, Kristina and Stanković, Dalibor M. and Vojs, Marian and Marton, Marian and Švorc, Lubomir",
year = "2018",
abstract = "In this work, the electrochemical oxidation and subsequent determination of uric acid was investigated using boron-doped diamond electrodes with various B/C ratios (0-2000 ppm). The cyclic voltammetric study showed one irreversible oxidation peak at +(1.1-1.25) V (vs. Ag/AgCl/3 M KCl) in the presence of Britton-Robinson buffer (pH 2.25) depending on the boron content. Employing differential pulse voltammetry using the 2000 ppm boron-doped diamond electrode the acquired analytical parameters were as follows: a limit of detection of 7.7 M, a limit of quantification of 26 M and intra-day repeatability (relative standard deviation of 2.9% for n = 15). After performing an interference study, the method was applied to the determination of uric acid in biological samples (human urine). The uric acid concentrations determined in the urine samples were compared with the reference values stated in the literature. The proposed methodology using boron-doped diamond electrodes could find applications in uric acid sensing within clinical, pharmaceutical and environmental analysis.",
journal = "Analytical Methods",
title = "The doping level of boron-doped diamond electrodes affects the voltammetric sensing of uric acid",
volume = "10",
number = "9",
pages = "991-996",
doi = "10.1039/C7AY02720F"
}

Cinkova, K., Kianičkova, K., Stanković, D. M., Vojs, M., Marton, M.,& Švorc, L.. (2018). The doping level of boron-doped diamond electrodes affects the voltammetric sensing of uric acid. in Analytical Methods, 10(9), 991-996.
https://doi.org/10.1039/C7AY02720F

Cinkova K, Kianičkova K, Stanković DM, Vojs M, Marton M, Švorc L. The doping level of boron-doped diamond electrodes affects the voltammetric sensing of uric acid. in Analytical Methods. 2018;10(9):991-996.
doi:10.1039/C7AY02720F .

Cinkova, Kristina, Kianičkova, Kristina, Stanković, Dalibor M., Vojs, Marian, Marton, Marian, Švorc, Lubomir, "The doping level of boron-doped diamond electrodes affects the voltammetric sensing of uric acid" in Analytical Methods, 10, no. 9 (2018):991-996,
https://doi.org/10.1039/C7AY02720F . .

TY  - JOUR
AU  - Samiec, Petr
AU  - Švorc, Lubomir
AU  - Stanković, Dalibor M.
AU  - Vojs, Marian
AU  - Marton, Marian
AU  - Navratilova, Zuzana
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8853
AB  - The boron-doped diamond electrodes (BDDEs) with different dopant levels were applied as advanced, mercury-free and modification-free electroanalytical platforms for simple and reliable quantification of benzodiazepines, bromazepam (BZ) and alprazolam (ALZ). Cyclic voltammetric measurements revealed that the electrode reactions of both analytes were manifested by one irreversible and diffusion-controlled reduction peak at -1.10V in Britton-Robinson buffer of pH 11 for BZ using lab-made BDDE with 1000 ppm B/C ratio and -0.84V in BR buffer of pH 5 for ALZ using commercial BDDE with 1000 ppm B/C ratio. Differential pulse voltammetry was used for construction of calibration curves for BZ and ALZ, respectively, with the analytical parameters as follows: the linear dynamic ranges of 1 x 10(-6)-1 x 10(-4) and 8 x 10(-7)-1 x 10(-4) mol/L, the detection limit of 3.1 x 10(-7) and 6.4 x 10(-7) mol/L and the excellent repeatability with the relative standard deviation below 3% for both drugs. The developed methods were applied to analysis of the pharmaceutical tablets with the recoveries from 97.33 to 100.85% for BZ and from 94.14 to 101.32% for ALZ. The usage of BDDEs as advanced electrochemical sensors in drug analysis represents a facile and effective analytical approach which may replace mercury-based sensors and chemically modified electrodes in previous benzodiazepines sensing. (C) 2017 Elsevier B.V. All rights reserved.
T2  - Sensors and Actuators B: Chemical
T1  - Mercury-free and modification-free electroanalytical approach towards bromazepam and alprazolam sensing: A facile and efficient assay for their quantification in pharmaceuticals using boron-doped diamond electrodes
VL  - 245
SP  - 963
EP  - 971
DO  - 10.1016/j.snb.2017.02.023
ER  - 

@article{
author = "Samiec, Petr and Švorc, Lubomir and Stanković, Dalibor M. and Vojs, Marian and Marton, Marian and Navratilova, Zuzana",
year = "2017",
abstract = "The boron-doped diamond electrodes (BDDEs) with different dopant levels were applied as advanced, mercury-free and modification-free electroanalytical platforms for simple and reliable quantification of benzodiazepines, bromazepam (BZ) and alprazolam (ALZ). Cyclic voltammetric measurements revealed that the electrode reactions of both analytes were manifested by one irreversible and diffusion-controlled reduction peak at -1.10V in Britton-Robinson buffer of pH 11 for BZ using lab-made BDDE with 1000 ppm B/C ratio and -0.84V in BR buffer of pH 5 for ALZ using commercial BDDE with 1000 ppm B/C ratio. Differential pulse voltammetry was used for construction of calibration curves for BZ and ALZ, respectively, with the analytical parameters as follows: the linear dynamic ranges of 1 x 10(-6)-1 x 10(-4) and 8 x 10(-7)-1 x 10(-4) mol/L, the detection limit of 3.1 x 10(-7) and 6.4 x 10(-7) mol/L and the excellent repeatability with the relative standard deviation below 3% for both drugs. The developed methods were applied to analysis of the pharmaceutical tablets with the recoveries from 97.33 to 100.85% for BZ and from 94.14 to 101.32% for ALZ. The usage of BDDEs as advanced electrochemical sensors in drug analysis represents a facile and effective analytical approach which may replace mercury-based sensors and chemically modified electrodes in previous benzodiazepines sensing. (C) 2017 Elsevier B.V. All rights reserved.",
journal = "Sensors and Actuators B: Chemical",
title = "Mercury-free and modification-free electroanalytical approach towards bromazepam and alprazolam sensing: A facile and efficient assay for their quantification in pharmaceuticals using boron-doped diamond electrodes",
volume = "245",
pages = "963-971",
doi = "10.1016/j.snb.2017.02.023"
}

Samiec, P., Švorc, L., Stanković, D. M., Vojs, M., Marton, M.,& Navratilova, Z.. (2017). Mercury-free and modification-free electroanalytical approach towards bromazepam and alprazolam sensing: A facile and efficient assay for their quantification in pharmaceuticals using boron-doped diamond electrodes. in Sensors and Actuators B: Chemical, 245, 963-971.
https://doi.org/10.1016/j.snb.2017.02.023

Samiec P, Švorc L, Stanković DM, Vojs M, Marton M, Navratilova Z. Mercury-free and modification-free electroanalytical approach towards bromazepam and alprazolam sensing: A facile and efficient assay for their quantification in pharmaceuticals using boron-doped diamond electrodes. in Sensors and Actuators B: Chemical. 2017;245:963-971.
doi:10.1016/j.snb.2017.02.023 .

Samiec, Petr, Švorc, Lubomir, Stanković, Dalibor M., Vojs, Marian, Marton, Marian, Navratilova, Zuzana, "Mercury-free and modification-free electroanalytical approach towards bromazepam and alprazolam sensing: A facile and efficient assay for their quantification in pharmaceuticals using boron-doped diamond electrodes" in Sensors and Actuators B: Chemical, 245 (2017):963-971,
https://doi.org/10.1016/j.snb.2017.02.023 . .

TY  - JOUR
AU  - Samiec, Petr
AU  - Švorc, Lubomir
AU  - Stanković, Dalibor M.
AU  - Vojs, Marian
AU  - Marton, Marian
AU  - Navratilova, Zuzana
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1504
AB  - The boron-doped diamond electrodes (BDDEs) with different dopant levels were applied as advanced, mercury-free and modification-free electroanalytical platforms for simple and reliable quantification of benzodiazepines, bromazepam (BZ) and alprazolam (ALZ). Cyclic voltammetric measurements revealed that the electrode reactions of both analytes were manifested by one irreversible and diffusion-controlled reduction peak at -1.10V in Britton-Robinson buffer of pH 11 for BZ using lab-made BDDE with 1000 ppm B/C ratio and -0.84V in BR buffer of pH 5 for ALZ using commercial BDDE with 1000 ppm B/C ratio. Differential pulse voltammetry was used for construction of calibration curves for BZ and ALZ, respectively, with the analytical parameters as follows: the linear dynamic ranges of 1 x 10(-6)-1 x 10(-4) and 8 x 10(-7)-1 x 10(-4) mol/L, the detection limit of 3.1 x 10(-7) and 6.4 x 10(-7) mol/L and the excellent repeatability with the relative standard deviation below 3% for both drugs. The developed methods were applied to analysis of the pharmaceutical tablets with the recoveries from 97.33 to 100.85% for BZ and from 94.14 to 101.32% for ALZ. The usage of BDDEs as advanced electrochemical sensors in drug analysis represents a facile and effective analytical approach which may replace mercury-based sensors and chemically modified electrodes in previous benzodiazepines sensing. (C) 2017 Elsevier B.V. All rights reserved.
T2  - Sensors and Actuators B: Chemical
T1  - Mercury-free and modification-free electroanalytical approach towards bromazepam and alprazolam sensing: A facile and efficient assay for their quantification in pharmaceuticals using boron-doped diamond electrodes
VL  - 245
SP  - 963
EP  - 971
DO  - 10.1016/j.snb.2017.02.023
ER  - 

@article{
author = "Samiec, Petr and Švorc, Lubomir and Stanković, Dalibor M. and Vojs, Marian and Marton, Marian and Navratilova, Zuzana",
year = "2017",
abstract = "The boron-doped diamond electrodes (BDDEs) with different dopant levels were applied as advanced, mercury-free and modification-free electroanalytical platforms for simple and reliable quantification of benzodiazepines, bromazepam (BZ) and alprazolam (ALZ). Cyclic voltammetric measurements revealed that the electrode reactions of both analytes were manifested by one irreversible and diffusion-controlled reduction peak at -1.10V in Britton-Robinson buffer of pH 11 for BZ using lab-made BDDE with 1000 ppm B/C ratio and -0.84V in BR buffer of pH 5 for ALZ using commercial BDDE with 1000 ppm B/C ratio. Differential pulse voltammetry was used for construction of calibration curves for BZ and ALZ, respectively, with the analytical parameters as follows: the linear dynamic ranges of 1 x 10(-6)-1 x 10(-4) and 8 x 10(-7)-1 x 10(-4) mol/L, the detection limit of 3.1 x 10(-7) and 6.4 x 10(-7) mol/L and the excellent repeatability with the relative standard deviation below 3% for both drugs. The developed methods were applied to analysis of the pharmaceutical tablets with the recoveries from 97.33 to 100.85% for BZ and from 94.14 to 101.32% for ALZ. The usage of BDDEs as advanced electrochemical sensors in drug analysis represents a facile and effective analytical approach which may replace mercury-based sensors and chemically modified electrodes in previous benzodiazepines sensing. (C) 2017 Elsevier B.V. All rights reserved.",
journal = "Sensors and Actuators B: Chemical",
title = "Mercury-free and modification-free electroanalytical approach towards bromazepam and alprazolam sensing: A facile and efficient assay for their quantification in pharmaceuticals using boron-doped diamond electrodes",
volume = "245",
pages = "963-971",
doi = "10.1016/j.snb.2017.02.023"
}

Samiec, P., Švorc, L., Stanković, D. M., Vojs, M., Marton, M.,& Navratilova, Z.. (2017). Mercury-free and modification-free electroanalytical approach towards bromazepam and alprazolam sensing: A facile and efficient assay for their quantification in pharmaceuticals using boron-doped diamond electrodes. in Sensors and Actuators B: Chemical, 245, 963-971.
https://doi.org/10.1016/j.snb.2017.02.023

Samiec P, Švorc L, Stanković DM, Vojs M, Marton M, Navratilova Z. Mercury-free and modification-free electroanalytical approach towards bromazepam and alprazolam sensing: A facile and efficient assay for their quantification in pharmaceuticals using boron-doped diamond electrodes. in Sensors and Actuators B: Chemical. 2017;245:963-971.
doi:10.1016/j.snb.2017.02.023 .

Samiec, Petr, Švorc, Lubomir, Stanković, Dalibor M., Vojs, Marian, Marton, Marian, Navratilova, Zuzana, "Mercury-free and modification-free electroanalytical approach towards bromazepam and alprazolam sensing: A facile and efficient assay for their quantification in pharmaceuticals using boron-doped diamond electrodes" in Sensors and Actuators B: Chemical, 245 (2017):963-971,
https://doi.org/10.1016/j.snb.2017.02.023 . .

TY  - JOUR
AU  - Shtereva, K. S.
AU  - Novotny, I.
AU  - Tvarozek, V.
AU  - Vojs, Marian
AU  - Flickyngerova, S.
AU  - Sutta, P.
AU  - Vincze, A.
AU  - Milosavljević, Momir
AU  - Jeynes, C.
AU  - Peng, N.
PY  - 2012
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/5518
AB  - The electrical characteristics of gallium-doped zinc oxide (ZnO:Ga) thin films prepared by rf diode sputtering were altered via nitrogen implantation by performing two implants at 40 keV and 80 keV with doses of 1 x 10(15) and 1 x 10(16) cm(-2) to achieve a p-type semiconductor. An implantation of 1 x 10(15) cm(-2) N+-ions yielded a p-type with hole concentrations 10(17)-10(18) cm(-3) in some as-implanted samples. The films annealed at temperatures above 200 degrees C in O-2 and above 400 degrees C in N-2 were n-type with electron concentrations 10(17)-10(20) cm(-3). The higher nitrogen concentration (confirmed by SRIM and SIMS), in the films implanted with a 1 x 10(16) cm(-2) dose, resulted in lower electron concentrations, respectively, higher resistivity, due to compensation of donors by nitrogen acceptors. The electron concentrations ratio n((1) (x) (1015))/ n((1 x 1016)) decreases with increasing annealing temperature. Hall measurements showed that 1 x 10(16) cm(-2) N-implanted films became p-type after low temperature annealing in O-2 at 200 degrees C and in N-2 at 400 degrees C with hole concentrations of 3.2 x 10(17) cm(-3) and 1.6 x 10(19) cm(-3), respectively. Nitrogen-implanted ZnO:Ga films showed a c-axes preferred orientation of the crystallites. Annealing is shown to increase the average transmittance ( GT 80%) of the films and to cause bandgap widening (3.19-3.3 eV). (C) 2012 The Electrochemical Society. All rights reserved.
T2  - ECS Journal of Solid State Science and Technology
T1  - Carrier Control in Polycrystalline ZnO:Ga Thin Films via Nitrogen Implantation
VL  - 1
IS  - 5
SP  - P237
EP  - P240
DO  - 10.1149/2.003206jss
ER  - 

@article{
author = "Shtereva, K. S. and Novotny, I. and Tvarozek, V. and Vojs, Marian and Flickyngerova, S. and Sutta, P. and Vincze, A. and Milosavljević, Momir and Jeynes, C. and Peng, N.",
year = "2012",
abstract = "The electrical characteristics of gallium-doped zinc oxide (ZnO:Ga) thin films prepared by rf diode sputtering were altered via nitrogen implantation by performing two implants at 40 keV and 80 keV with doses of 1 x 10(15) and 1 x 10(16) cm(-2) to achieve a p-type semiconductor. An implantation of 1 x 10(15) cm(-2) N+-ions yielded a p-type with hole concentrations 10(17)-10(18) cm(-3) in some as-implanted samples. The films annealed at temperatures above 200 degrees C in O-2 and above 400 degrees C in N-2 were n-type with electron concentrations 10(17)-10(20) cm(-3). The higher nitrogen concentration (confirmed by SRIM and SIMS), in the films implanted with a 1 x 10(16) cm(-2) dose, resulted in lower electron concentrations, respectively, higher resistivity, due to compensation of donors by nitrogen acceptors. The electron concentrations ratio n((1) (x) (1015))/ n((1 x 1016)) decreases with increasing annealing temperature. Hall measurements showed that 1 x 10(16) cm(-2) N-implanted films became p-type after low temperature annealing in O-2 at 200 degrees C and in N-2 at 400 degrees C with hole concentrations of 3.2 x 10(17) cm(-3) and 1.6 x 10(19) cm(-3), respectively. Nitrogen-implanted ZnO:Ga films showed a c-axes preferred orientation of the crystallites. Annealing is shown to increase the average transmittance ( GT 80%) of the films and to cause bandgap widening (3.19-3.3 eV). (C) 2012 The Electrochemical Society. All rights reserved.",
journal = "ECS Journal of Solid State Science and Technology",
title = "Carrier Control in Polycrystalline ZnO:Ga Thin Films via Nitrogen Implantation",
volume = "1",
number = "5",
pages = "P237-P240",
doi = "10.1149/2.003206jss"
}

Shtereva, K. S., Novotny, I., Tvarozek, V., Vojs, M., Flickyngerova, S., Sutta, P., Vincze, A., Milosavljević, M., Jeynes, C.,& Peng, N.. (2012). Carrier Control in Polycrystalline ZnO:Ga Thin Films via Nitrogen Implantation. in ECS Journal of Solid State Science and Technology, 1(5), P237-P240.
https://doi.org/10.1149/2.003206jss

Shtereva KS, Novotny I, Tvarozek V, Vojs M, Flickyngerova S, Sutta P, Vincze A, Milosavljević M, Jeynes C, Peng N. Carrier Control in Polycrystalline ZnO:Ga Thin Films via Nitrogen Implantation. in ECS Journal of Solid State Science and Technology. 2012;1(5):P237-P240.
doi:10.1149/2.003206jss .

Shtereva, K. S., Novotny, I., Tvarozek, V., Vojs, Marian, Flickyngerova, S., Sutta, P., Vincze, A., Milosavljević, Momir, Jeynes, C., Peng, N., "Carrier Control in Polycrystalline ZnO:Ga Thin Films via Nitrogen Implantation" in ECS Journal of Solid State Science and Technology, 1, no. 5 (2012):P237-P240,
https://doi.org/10.1149/2.003206jss . .