TY  - JOUR
AU  - Djurišić, Ivana
AU  - Dražić, Miloš S.
AU  - Tomović, Aleksandar Ž.
AU  - Spasenović, Marko
AU  - Šljivančanin, Željko
AU  - Jovanović, Vladimir P.
AU  - Zikić, Radomir
PY  - 2021
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/4049
AB  - Single-molecule biosensing, with a promise of being applied in protein and DNA sequencing, could be achieved using tunneling current approach. Electrode-molecule-electrode tunneling current critically depends on whether molecular levels contribute to electronic transport or not. Here we found employing DFT and Non-Equilibrium Green's Function formalism that energies of benzene molecular levels placed between graphene electrodes are strongly influenced by electrode termination. Termination-dependent dipoles formed at the electrode ends induce in-gap field effect that is responsible for shifting of molecular levels. We show that the HOMO is closest to Fermi energy for nitrogen-terminated nanogaps (NtNGs) and nanopores (NtNPs), promoting them as strong candidates for single-molecule sensing applications.
PB  - Wiley
T2  - ChemPhysChem
T1  - Field Effect and Local Gating in Nitrogen‐Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene
VL  - 22
IS  - 3
SP  - 336
EP  - 341
DO  - 10.1002/cphc.202000771
ER  - 

@article{
author = "Djurišić, Ivana and Dražić, Miloš S. and Tomović, Aleksandar Ž. and Spasenović, Marko and Šljivančanin, Željko and Jovanović, Vladimir P. and Zikić, Radomir",
year = "2021",
abstract = "Single-molecule biosensing, with a promise of being applied in protein and DNA sequencing, could be achieved using tunneling current approach. Electrode-molecule-electrode tunneling current critically depends on whether molecular levels contribute to electronic transport or not. Here we found employing DFT and Non-Equilibrium Green's Function formalism that energies of benzene molecular levels placed between graphene electrodes are strongly influenced by electrode termination. Termination-dependent dipoles formed at the electrode ends induce in-gap field effect that is responsible for shifting of molecular levels. We show that the HOMO is closest to Fermi energy for nitrogen-terminated nanogaps (NtNGs) and nanopores (NtNPs), promoting them as strong candidates for single-molecule sensing applications.",
publisher = "Wiley",
journal = "ChemPhysChem",
title = "Field Effect and Local Gating in Nitrogen‐Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene",
volume = "22",
number = "3",
pages = "336-341",
doi = "10.1002/cphc.202000771"
}

Djurišić, I., Dražić, M. S., Tomović, A. Ž., Spasenović, M., Šljivančanin, Ž., Jovanović, V. P.,& Zikić, R.. (2021). Field Effect and Local Gating in Nitrogen‐Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene. in ChemPhysChem
Wiley., 22(3), 336-341.
https://doi.org/10.1002/cphc.202000771

Djurišić I, Dražić MS, Tomović AŽ, Spasenović M, Šljivančanin Ž, Jovanović VP, Zikić R. Field Effect and Local Gating in Nitrogen‐Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene. in ChemPhysChem. 2021;22(3):336-341.
doi:10.1002/cphc.202000771 .

Djurišić, Ivana, Dražić, Miloš S., Tomović, Aleksandar Ž., Spasenović, Marko, Šljivančanin, Željko, Jovanović, Vladimir P., Zikić, Radomir, "Field Effect and Local Gating in Nitrogen‐Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene" in ChemPhysChem, 22, no. 3 (2021):336-341,
https://doi.org/10.1002/cphc.202000771 . .

TY  - JOUR
AU  - Djurišić, Ivana
AU  - Dražić, Miloš S.
AU  - Tomović, Aleksandar Ž.
AU  - Spasenović, Marko
AU  - Šljivančanin, Željko
AU  - Jovanović, Vladimir P.
AU  - Zikić, Radomir
PY  - 2021
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/4048
AB  - Functionalization of electrodes is a wide‐used strategy in various applications ranging from single‐molecule sensing and protein sequencing, to ion trapping, to desalination. We demonstrate, employing non‐equilibrium Green′s function formalism combined with density functional theory, that single‐species (N, H, S, Cl, F) termination of graphene nanogap electrodes results in a strong in‐gap electrostatic field, induced by species‐dependent dipoles formed at the electrode ends. Consequently, the field increases or decreases electronic transport through a molecule (benzene) placed in the nanogap by shifting molecular levels by almost 2 eV in respect to the electrode Fermi level via a field effect akin to the one used for field‐effect transistors. We also observed the local gating in graphene nanopores terminated with different single‐species atoms. Nitrogen‐terminated nanogaps (NtNGs) and nanopores (NtNPs) show the strongest effect. The in‐gap potential can be transformed from a plateau‐like to a saddle‐like shape by tailoring NtNG and NtNP size and termination type. In particular, the saddle‐like potential is applicable in single‐ion trapping and desalination devices.
PB  - Wiley
T2  - ChemPhysChem
T1  - Field Effect and Local Gating in Nitrogen‐Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene
VL  - 22
IS  - 3
SP  - 336
EP  - 341
DO  - 10.1002/cphc.202000771
ER  - 

@article{
author = "Djurišić, Ivana and Dražić, Miloš S. and Tomović, Aleksandar Ž. and Spasenović, Marko and Šljivančanin, Željko and Jovanović, Vladimir P. and Zikić, Radomir",
year = "2021",
abstract = "Functionalization of electrodes is a wide‐used strategy in various applications ranging from single‐molecule sensing and protein sequencing, to ion trapping, to desalination. We demonstrate, employing non‐equilibrium Green′s function formalism combined with density functional theory, that single‐species (N, H, S, Cl, F) termination of graphene nanogap electrodes results in a strong in‐gap electrostatic field, induced by species‐dependent dipoles formed at the electrode ends. Consequently, the field increases or decreases electronic transport through a molecule (benzene) placed in the nanogap by shifting molecular levels by almost 2 eV in respect to the electrode Fermi level via a field effect akin to the one used for field‐effect transistors. We also observed the local gating in graphene nanopores terminated with different single‐species atoms. Nitrogen‐terminated nanogaps (NtNGs) and nanopores (NtNPs) show the strongest effect. The in‐gap potential can be transformed from a plateau‐like to a saddle‐like shape by tailoring NtNG and NtNP size and termination type. In particular, the saddle‐like potential is applicable in single‐ion trapping and desalination devices.",
publisher = "Wiley",
journal = "ChemPhysChem",
title = "Field Effect and Local Gating in Nitrogen‐Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene",
volume = "22",
number = "3",
pages = "336-341",
doi = "10.1002/cphc.202000771"
}

Djurišić, I., Dražić, M. S., Tomović, A. Ž., Spasenović, M., Šljivančanin, Ž., Jovanović, V. P.,& Zikić, R.. (2021). Field Effect and Local Gating in Nitrogen‐Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene. in ChemPhysChem
Wiley., 22(3), 336-341.
https://doi.org/10.1002/cphc.202000771

Djurišić I, Dražić MS, Tomović AŽ, Spasenović M, Šljivančanin Ž, Jovanović VP, Zikić R. Field Effect and Local Gating in Nitrogen‐Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene. in ChemPhysChem. 2021;22(3):336-341.
doi:10.1002/cphc.202000771 .

Djurišić, Ivana, Dražić, Miloš S., Tomović, Aleksandar Ž., Spasenović, Marko, Šljivančanin, Željko, Jovanović, Vladimir P., Zikić, Radomir, "Field Effect and Local Gating in Nitrogen‐Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene" in ChemPhysChem, 22, no. 3 (2021):336-341,
https://doi.org/10.1002/cphc.202000771 . .

TY  - JOUR
AU  - Djurišić, Ivana
AU  - Dražić, Miloš S.
AU  - Tomović, Aleksandar Ž.
AU  - Spasenović, Marko
AU  - Šljivančanin, Željko
AU  - Jovanović, Vladimir P.
AU  - Zikić, Radomir
PY  - 2021
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/4044
AB  - Functionalization of electrodes is a wide‐used strategy in various applications ranging from single‐molecule sensing and protein sequencing, to ion trapping, to desalination. We demonstrate, employing non‐equilibrium Green′s function formalism combined with density functional theory, that single‐species (N, H, S, Cl, F) termination of graphene nanogap electrodes results in a strong in‐gap electrostatic field, induced by species‐dependent dipoles formed at the electrode ends. Consequently, the field increases or decreases electronic transport through a molecule (benzene) placed in the nanogap by shifting molecular levels by almost 2 eV in respect to the electrode Fermi level via a field effect akin to the one used for field‐effect transistors. We also observed the local gating in graphene nanopores terminated with different single‐species atoms. Nitrogen‐terminated nanogaps (NtNGs) and nanopores (NtNPs) show the strongest effect. The in‐gap potential can be transformed from a plateau‐like to a saddle‐like shape by tailoring NtNG and NtNP size and termination type. In particular, the saddle‐like potential is applicable in single‐ion trapping and desalination devices.
PB  - Wiley
T2  - ChemPhysChem
T1  - Field Effect and Local Gating in Nitrogen‐Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene
VL  - 22
IS  - 3
SP  - 336
EP  - 341
DO  - 10.1002/cphc.202000771
ER  - 

@article{
author = "Djurišić, Ivana and Dražić, Miloš S. and Tomović, Aleksandar Ž. and Spasenović, Marko and Šljivančanin, Željko and Jovanović, Vladimir P. and Zikić, Radomir",
year = "2021",
abstract = "Functionalization of electrodes is a wide‐used strategy in various applications ranging from single‐molecule sensing and protein sequencing, to ion trapping, to desalination. We demonstrate, employing non‐equilibrium Green′s function formalism combined with density functional theory, that single‐species (N, H, S, Cl, F) termination of graphene nanogap electrodes results in a strong in‐gap electrostatic field, induced by species‐dependent dipoles formed at the electrode ends. Consequently, the field increases or decreases electronic transport through a molecule (benzene) placed in the nanogap by shifting molecular levels by almost 2 eV in respect to the electrode Fermi level via a field effect akin to the one used for field‐effect transistors. We also observed the local gating in graphene nanopores terminated with different single‐species atoms. Nitrogen‐terminated nanogaps (NtNGs) and nanopores (NtNPs) show the strongest effect. The in‐gap potential can be transformed from a plateau‐like to a saddle‐like shape by tailoring NtNG and NtNP size and termination type. In particular, the saddle‐like potential is applicable in single‐ion trapping and desalination devices.",
publisher = "Wiley",
journal = "ChemPhysChem",
title = "Field Effect and Local Gating in Nitrogen‐Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene",
volume = "22",
number = "3",
pages = "336-341",
doi = "10.1002/cphc.202000771"
}

Djurišić, I., Dražić, M. S., Tomović, A. Ž., Spasenović, M., Šljivančanin, Ž., Jovanović, V. P.,& Zikić, R.. (2021). Field Effect and Local Gating in Nitrogen‐Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene. in ChemPhysChem
Wiley., 22(3), 336-341.
https://doi.org/10.1002/cphc.202000771

Djurišić I, Dražić MS, Tomović AŽ, Spasenović M, Šljivančanin Ž, Jovanović VP, Zikić R. Field Effect and Local Gating in Nitrogen‐Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene. in ChemPhysChem. 2021;22(3):336-341.
doi:10.1002/cphc.202000771 .

Djurišić, Ivana, Dražić, Miloš S., Tomović, Aleksandar Ž., Spasenović, Marko, Šljivančanin, Željko, Jovanović, Vladimir P., Zikić, Radomir, "Field Effect and Local Gating in Nitrogen‐Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene" in ChemPhysChem, 22, no. 3 (2021):336-341,
https://doi.org/10.1002/cphc.202000771 . .

TY  - JOUR
AU  - Đurišić, Ivana
AU  - Dražić, Miloš S.
AU  - Tomović, Aleksandar Ž.
AU  - Spasenović, Marko
AU  - Šlivančanin, Željko
AU  - Jovanović, Vladimir P.
AU  - Zikić, Radomir
PY  - 2020
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3632
AB  - Fast, reliable, and inexpensive DNA sequencing is an important pursuit in healthcare, especially in personalized medicine with possible deep societal impacts. Despite significant progress in various nanopore-based sequencing configurations, challenges that remain in resolution and chromosome-size-long readout call for new approaches. Here we found strong rectification in the transversal current during single-stranded DNA translocation through a nanopore with side-embedded N-terminated carbon nanotube electrodes. Employing density functional theory and nonequilibrium Green’s function formalisms, we show that the rectifying ratio (response to square pulses of alternating bias) bears high nucleobase specificity. Rectification arises because of bias-dependent resistance asymmetry on the deoxyribonucleotide−electrode interfaces. The asymmetry induces molecular charging and highest occupied molecular orbital pinning to the electrochemical potential of one of the electrodes, assisted by an in-gap electric-field effect caused by dipoles at the terminated electrode ends. We propose the rectifying ratio, due to its order-of-magnitude-difference nucleobase selectivity and robustness to electrode-molecule orientation, as a promising readout quantifier for single-base resolution and chromosome-size-long single-read DNA sequencing. The proposed configurations are within experimental reach from the viewpoint of both nanofabrication and small current measurement.
PB  - American Chemical Society (ACS)
T2  - ACS Applied Nano Materials
T1  - DNA Sequencing with Single-Stranded DNA Rectification in a Nanogap Gated by N‑Terminated Carbon Nanotube Electrodes
VL  - 3
IS  - 3
SP  - 3034
EP  - 3043
DO  - 10.1021/acsanm.0c00385
ER  - 

@article{
author = "Đurišić, Ivana and Dražić, Miloš S. and Tomović, Aleksandar Ž. and Spasenović, Marko and Šlivančanin, Željko and Jovanović, Vladimir P. and Zikić, Radomir",
year = "2020",
abstract = "Fast, reliable, and inexpensive DNA sequencing is an important pursuit in healthcare, especially in personalized medicine with possible deep societal impacts. Despite significant progress in various nanopore-based sequencing configurations, challenges that remain in resolution and chromosome-size-long readout call for new approaches. Here we found strong rectification in the transversal current during single-stranded DNA translocation through a nanopore with side-embedded N-terminated carbon nanotube electrodes. Employing density functional theory and nonequilibrium Green’s function formalisms, we show that the rectifying ratio (response to square pulses of alternating bias) bears high nucleobase specificity. Rectification arises because of bias-dependent resistance asymmetry on the deoxyribonucleotide−electrode interfaces. The asymmetry induces molecular charging and highest occupied molecular orbital pinning to the electrochemical potential of one of the electrodes, assisted by an in-gap electric-field effect caused by dipoles at the terminated electrode ends. We propose the rectifying ratio, due to its order-of-magnitude-difference nucleobase selectivity and robustness to electrode-molecule orientation, as a promising readout quantifier for single-base resolution and chromosome-size-long single-read DNA sequencing. The proposed configurations are within experimental reach from the viewpoint of both nanofabrication and small current measurement.",
publisher = "American Chemical Society (ACS)",
journal = "ACS Applied Nano Materials",
title = "DNA Sequencing with Single-Stranded DNA Rectification in a Nanogap Gated by N‑Terminated Carbon Nanotube Electrodes",
volume = "3",
number = "3",
pages = "3034-3043",
doi = "10.1021/acsanm.0c00385"
}

Đurišić, I., Dražić, M. S., Tomović, A. Ž., Spasenović, M., Šlivančanin, Ž., Jovanović, V. P.,& Zikić, R.. (2020). DNA Sequencing with Single-Stranded DNA Rectification in a Nanogap Gated by N‑Terminated Carbon Nanotube Electrodes. in ACS Applied Nano Materials
American Chemical Society (ACS)., 3(3), 3034-3043.
https://doi.org/10.1021/acsanm.0c00385

Đurišić I, Dražić MS, Tomović AŽ, Spasenović M, Šlivančanin Ž, Jovanović VP, Zikić R. DNA Sequencing with Single-Stranded DNA Rectification in a Nanogap Gated by N‑Terminated Carbon Nanotube Electrodes. in ACS Applied Nano Materials. 2020;3(3):3034-3043.
doi:10.1021/acsanm.0c00385 .

Đurišić, Ivana, Dražić, Miloš S., Tomović, Aleksandar Ž., Spasenović, Marko, Šlivančanin, Željko, Jovanović, Vladimir P., Zikić, Radomir, "DNA Sequencing with Single-Stranded DNA Rectification in a Nanogap Gated by N‑Terminated Carbon Nanotube Electrodes" in ACS Applied Nano Materials, 3, no. 3 (2020):3034-3043,
https://doi.org/10.1021/acsanm.0c00385 . .

TY  - JOUR
AU  - Tomović, Aleksandar Ž.
AU  - Jovanović, Vladimir P.
AU  - Durisic, I
AU  - Cerovski, V Z
AU  - Nastasijevic, B
AU  - Veielovic, S R
AU  - Radulović, Katarina
AU  - Zikić, Radomir
PY  - 2015
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/1669
AB  - The photoluminescence (PL) quenching mechanism of UV light and air-exposed amorphous thin films of 4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl (DPVBi), a well-known hole-transport material used in organic light-emitting diodes, is studied. Thin films of DPVBi are stable when exposed to UV light in vacuum but tend to degrade if oxygen is present simultaneously. This is evident from the changes in UV-vis absorption spectra of the latter, showing that degradation rate of DPVBi films is linearly proportional to both oxygen concentration and UV light intensity. Mass spectrometry study of such films revealed a number of different oxygen-containing molecules and fragments of DPVBi thus confirming apparent photo-oxidation process. Also, DFT study of molecular DPVBi with and without oxygen was carried out, the IR spectra calculated for the lowest energy molecules found and the results are compared with the experiment. The most sensitive to photo-oxidation is DPVBi photoluminescence, which decays exponentially with respect to the concentration of photo-oxidized DPVBi molecules (impurities). The PL quantum yield of DPVBi thin film drops to a half of its original value for 0.2% of the impurities present, at which point an average distance between DPVBi molecules (the donors) and photo-oxidized DPVBi species (acceptors) is an order of magnitude larger than the separation between two adjacent molecules. This implies a need for a long-range Forster energy transfer, which we rule out based on the lack of a donor-acceptor spectral overlap. The apparent discrepancy can be removed by postulating exciton self-diffusion in DPVBi thin films, for which there is supporting evidence in existing literature.
PB  - Elsevier
T2  - Journal of Luminescence
T1  - Fast photoluminescence quenching in thin films of 4,4 '-bis(2,2-diphenylvinyl)-1,1 '-biphenyl exposed to air
VL  - 167
SP  - 204
EP  - 210
DO  - 10.1016/j.jlumin.2015.06.036
ER  - 

@article{
author = "Tomović, Aleksandar Ž. and Jovanović, Vladimir P. and Durisic, I and Cerovski, V Z and Nastasijevic, B and Veielovic, S R and Radulović, Katarina and Zikić, Radomir",
year = "2015",
abstract = "The photoluminescence (PL) quenching mechanism of UV light and air-exposed amorphous thin films of 4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl (DPVBi), a well-known hole-transport material used in organic light-emitting diodes, is studied. Thin films of DPVBi are stable when exposed to UV light in vacuum but tend to degrade if oxygen is present simultaneously. This is evident from the changes in UV-vis absorption spectra of the latter, showing that degradation rate of DPVBi films is linearly proportional to both oxygen concentration and UV light intensity. Mass spectrometry study of such films revealed a number of different oxygen-containing molecules and fragments of DPVBi thus confirming apparent photo-oxidation process. Also, DFT study of molecular DPVBi with and without oxygen was carried out, the IR spectra calculated for the lowest energy molecules found and the results are compared with the experiment. The most sensitive to photo-oxidation is DPVBi photoluminescence, which decays exponentially with respect to the concentration of photo-oxidized DPVBi molecules (impurities). The PL quantum yield of DPVBi thin film drops to a half of its original value for 0.2% of the impurities present, at which point an average distance between DPVBi molecules (the donors) and photo-oxidized DPVBi species (acceptors) is an order of magnitude larger than the separation between two adjacent molecules. This implies a need for a long-range Forster energy transfer, which we rule out based on the lack of a donor-acceptor spectral overlap. The apparent discrepancy can be removed by postulating exciton self-diffusion in DPVBi thin films, for which there is supporting evidence in existing literature.",
publisher = "Elsevier",
journal = "Journal of Luminescence",
title = "Fast photoluminescence quenching in thin films of 4,4 '-bis(2,2-diphenylvinyl)-1,1 '-biphenyl exposed to air",
volume = "167",
pages = "204-210",
doi = "10.1016/j.jlumin.2015.06.036"
}

Tomović, A. Ž., Jovanović, V. P., Durisic, I., Cerovski, V. Z., Nastasijevic, B., Veielovic, S. R., Radulović, K.,& Zikić, R.. (2015). Fast photoluminescence quenching in thin films of 4,4 '-bis(2,2-diphenylvinyl)-1,1 '-biphenyl exposed to air. in Journal of Luminescence
Elsevier., 167, 204-210.
https://doi.org/10.1016/j.jlumin.2015.06.036

Tomović AŽ, Jovanović VP, Durisic I, Cerovski VZ, Nastasijevic B, Veielovic SR, Radulović K, Zikić R. Fast photoluminescence quenching in thin films of 4,4 '-bis(2,2-diphenylvinyl)-1,1 '-biphenyl exposed to air. in Journal of Luminescence. 2015;167:204-210.
doi:10.1016/j.jlumin.2015.06.036 .

Tomović, Aleksandar Ž., Jovanović, Vladimir P., Durisic, I, Cerovski, V Z, Nastasijevic, B, Veielovic, S R, Radulović, Katarina, Zikić, Radomir, "Fast photoluminescence quenching in thin films of 4,4 '-bis(2,2-diphenylvinyl)-1,1 '-biphenyl exposed to air" in Journal of Luminescence, 167 (2015):204-210,
https://doi.org/10.1016/j.jlumin.2015.06.036 . .