dr Sebastian Szewczyk

Zainteresowania naukowe
- Ultraszybka, czasowo-rozdzielcza spektroskopia laserowa – fizyczne podstawy, eksperyment, metody analizy danych
- Badanie własności elektrochemicznych i optycznych układów fotosyntetycznych odłożonych na nieorganicznych podłożach
- Izolacja i oczyszczanie białek fotosyntetycznych, hodowla komórkowa, techniki biochemiczne
Wykształcenie
- II Liceum Ogólnokształcące we Wrześni, 2007
- magister biofizyki, Wydział Fizyki UAM, 2012
- doktor biofizyki, Wydział Fizyki UAM, 2018
Inne informacje
- Asystent w ZBM od 2016
- Kierownik projektu „W kierunku wykorzystania Fotosystemu I do budowy biohybrydowych ogniw fotowoltaicznych”,
nr 0041/DIA/2012. MNiSW, 2012-2016. - Wykonawca w projekcie NCN pt. „Bio-półprzewodnikowe hybrydy do komórek fotowoltaicznych” nr 2012/07/B/NZ1/02639, 2013-2018.
- Wykonawca w licznych, krótkoterminowych projektach „Laserlab Europe” – 2010-2016.
Staże w innych ośrodkach naukowych
- Vrije Univeristeit Amsterdam, Wydział Nauki, zakład Fizyki i Astronomii – staże miesięczne i dwutygodniowe, łącznie 6 miesięcy
- Instytut Fizyki PAN w Warszawie, Laboratorium Fizyki Biologicznej – łącznie 2 miesiące.
- Uniwersytet Medyczny w Poznaniu, Katedra i Klinika Neurologii, Zakład Neurobiologii – łącznie 1 miesiąc.
Dydaktyka
- Fotobiofizyka I, część I oraz II (laboratorium)
- Fotobiofizyka II (laboratorium/ćwiczenia)
- Biofizyka fotosyntezy (laboratorium)
- Spektroskopia układów fotosyntetycznych (laboratorum/ćwiczenia)
- Repetytorium z matematyki (ćwiczenia)
- Podstawy biofizyki (studia niestacjonarne, laboratorium)
2022
Szewczyk, Sebastian; Goyal, Alice; Abram, Mateusz; Burdziński, Gotard; Kargul, Joanna; Gibasiewicz, Krzysztof
Electron Transfer in a Bio-Photoelectrode Based on Photosystem I Multilayer Immobilized on the Conducting Glass Journal Article
In: International Journal of Molecular Sciences, vol. 23, no. 9, pp. 4774, 2022.
@article{Szewczyk2022b,
title = {Electron Transfer in a Bio-Photoelectrode Based on Photosystem I Multilayer Immobilized on the Conducting Glass},
author = {Sebastian Szewczyk and Alice Goyal and Mateusz Abram and Gotard Burdziński and Joanna Kargul and Krzysztof Gibasiewicz},
url = {https://doi.org/10.3390/ijms23094774},
doi = {10.3390/ijms23094774},
year = {2022},
date = {2022-04-01},
journal = {International Journal of Molecular Sciences},
volume = {23},
number = {9},
pages = {4774},
publisher = {MDPI AG},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Goyal, Alice; Szewczyk, Sebastian; Burdziński, Gotard; Abram, Mateusz; Kargul, Joanna; Gibasiewicz, Krzysztof
Competition between intra-protein charge recombination and electron transfer outside photosystem I complexes used for photovoltaic applications Journal Article
In: Photochemical &$mathsemicolon$ Photobiological Sciences, vol. 21, no. 3, pp. 319–336, 2022.
@article{Goyal2022,
title = {Competition between intra-protein charge recombination and electron transfer outside photosystem I complexes used for photovoltaic applications},
author = {Alice Goyal and Sebastian Szewczyk and Gotard Burdziński and Mateusz Abram and Joanna Kargul and Krzysztof Gibasiewicz},
url = {https://doi.org/10.1007/s43630-022-00170-x},
doi = {10.1007/s43630-022-00170-x},
year = {2022},
date = {2022-02-01},
journal = {Photochemical &$mathsemicolon$ Photobiological Sciences},
volume = {21},
number = {3},
pages = {319--336},
publisher = {Springer Science and Business Media LLC},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2021
Dubas, Katarzyna; Szewczyk, Sebastian; Białek, Rafał; Burdziński, G; Jones, M R; Gibasiewicz, Krzysztof
Antagonistic Effects of Point Mutations on Charge Recombination and a New View of Primary Charge Separation in Photosynthetic Proteins Journal Article
In: The Journal of Physical Chemistry B, vol. 125, no. 31, pp. 8742–8756, 2021.
@article{Dubas2021,
title = {Antagonistic Effects of Point Mutations on Charge Recombination and a New View of Primary Charge Separation in Photosynthetic Proteins},
author = {Katarzyna Dubas and Sebastian Szewczyk and Rafał Białek and G Burdziński and M R Jones and Krzysztof Gibasiewicz},
url = {https://doi.org/10.1021/acs.jpcb.1c03978},
doi = {10.1021/acs.jpcb.1c03978},
year = {2021},
date = {2021-01-01},
journal = {The Journal of Physical Chemistry B},
volume = {125},
number = {31},
pages = {8742--8756},
publisher = {American Chemical Society (ACS)},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2020
Szewczyk, Sebastian; Abram, Mateusz; Białek, Rafał; Haniewicz, Patrycja; Karolczak, Jerzy; Gapiński, Jacek; Kargul, Joanna; Gibasiewicz, Krzysztof
On the nature of uncoupled chlorophylls in the extremophilic photosystem I-light harvesting I supercomplex Journal Article
In: Biochimica et Biophysica Acta (BBA) - Bioenergetics, vol. 1861, no. 2, pp. 148136, 2020, ISSN: 00052728.
@article{Szewczyk2020,
title = {On the nature of uncoupled chlorophylls in the extremophilic photosystem I-light harvesting I supercomplex},
author = {Sebastian Szewczyk and Mateusz Abram and Rafał Białek and Patrycja Haniewicz and Jerzy Karolczak and Jacek Gapiński and Joanna Kargul and Krzysztof Gibasiewicz},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0005272819301902},
doi = {10.1016/j.bbabio.2019.148136},
issn = {00052728},
year = {2020},
date = {2020-02-01},
journal = {Biochimica et Biophysica Acta (BBA) - Bioenergetics},
volume = {1861},
number = {2},
pages = {148136},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Szewczyk, Sebastian; Białek, Rafał; Giera, Wojciech; Burdziński, G; van Grondelle, Rienk; Gibasiewicz, Krzysztof
Excitation dynamics in Photosystem I trapped in TiO2 mesopores Journal Article
In: Photosynthesis Research, no. 0123456789, 2020, ISSN: 0166-8595.
Abstract | Links | BibTeX | Tagi: Excitation dynamics, Photosystem I, Primary charge separation, Synechocystis, Target analysis, Time-resolved fluorescence, Transient absorption
@article{Szewczyk2020b,
title = {Excitation dynamics in Photosystem I trapped in TiO2 mesopores},
author = {Sebastian Szewczyk and Rafał Białek and Wojciech Giera and G Burdziński and Rienk van Grondelle and Krzysztof Gibasiewicz},
url = {https://doi.org/10.1007/s11120-020-00730-1 http://link.springer.com/10.1007/s11120-020-00730-1},
doi = {10.1007/s11120-020-00730-1},
issn = {0166-8595},
year = {2020},
date = {2020-02-01},
journal = {Photosynthesis Research},
number = {0123456789},
publisher = {Springer Netherlands},
abstract = {Excitation decay in closed Photosystem I (PSI) isolated from cyanobacterium Synechocystis sp. PCC 6803 and dissolved in a buffer solution occurs predominantly with a ~ 24-ps lifetime, as measured both by time-resolved fluorescence and transient absorption. The same PSI particles deposited in mesoporous matrix made of TiO2 nanoparticles exhibit significantly accelerated excitation decay dominated by a ~ 6-ps component. Target analysis indicates that this acceleration is caused by ~ 50% increase of the rate constant of bulk Chls excitation quenching. As an effect of this increase, as much as ~ 70% of bulk Chls excitation is quenched before the establishment of equilibrium with the red Chls. Accelerated quenching may be caused by increased excitation trapping by the reaction center and/or quenching properties of the TiO2 surface directly interacting with PSI Chls. Also properties of the PSI red Chls are affected by the deposition in the TiO2 matrix: they become deeper traps due to an increase of their number and their oscillator strength is significantly reduced. These effects should be taken into account when constructing solar cells' photoelectrodes composed of PSI and artificial matrices.},
keywords = {Excitation dynamics, Photosystem I, Primary charge separation, Synechocystis, Target analysis, Time-resolved fluorescence, Transient absorption},
pubstate = {published},
tppubtype = {article}
}
Szewczyk, Sebastian; Białek, Rafał; Burdziński, Gotard; Gibasiewicz, Krzysztof
Photovoltaic activity of electrodes based on intact photosystem I electrodeposited on bare conducting glass Journal Article
In: Photosynthesis Research, no. 0123456789, 2020, ISSN: 0166-8595.
Links | BibTeX | Tagi: cyanobacterium synechocystis sp, Cyanobacterium Synechocystis sp. PCC 6803, Femtosecond-transient absorption, FTO conducting glass, pcc 6803, Photoelectrochemical measurements, Photosystem I, Photovoltaics
@article{Szewczyk2020c,
title = {Photovoltaic activity of electrodes based on intact photosystem I electrodeposited on bare conducting glass},
author = {Sebastian Szewczyk and Rafał Białek and Gotard Burdziński and Krzysztof Gibasiewicz},
url = {https://doi.org/10.1007/s11120-020-00722-1 http://link.springer.com/10.1007/s11120-020-00722-1},
doi = {10.1007/s11120-020-00722-1},
issn = {0166-8595},
year = {2020},
date = {2020-02-01},
journal = {Photosynthesis Research},
number = {0123456789},
publisher = {Springer Netherlands},
keywords = {cyanobacterium synechocystis sp, Cyanobacterium Synechocystis sp. PCC 6803, Femtosecond-transient absorption, FTO conducting glass, pcc 6803, Photoelectrochemical measurements, Photosystem I, Photovoltaics},
pubstate = {published},
tppubtype = {article}
}
Abram, Mateusz; Białek, Rafał; Szewczyk, Sebastian; Karolczak, Jerzy; Gibasiewicz, Krzysztof; Kargul, Joanna
Remodeling of excitation energy transfer in extremophilic red algal PSI-LHCI complex during light adaptation Journal Article
In: Biochimica et Biophysica Acta (BBA) - Bioenergetics, vol. 1861, no. 1, pp. 148093, 2020, ISSN: 00052728.
@article{Abram2020,
title = {Remodeling of excitation energy transfer in extremophilic red algal PSI-LHCI complex during light adaptation},
author = {Mateusz Abram and Rafał Białek and Sebastian Szewczyk and Jerzy Karolczak and Krzysztof Gibasiewicz and Joanna Kargul},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0005272819301409},
doi = {10.1016/j.bbabio.2019.148093},
issn = {00052728},
year = {2020},
date = {2020-01-01},
journal = {Biochimica et Biophysica Acta (BBA) - Bioenergetics},
volume = {1861},
number = {1},
pages = {148093},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2018
Szewczyk, Sebastian; Giera, Wojciech; Białek, Rafał; Burdziński, Gotard; Gibasiewicz, Krzysztof
Acceleration of the excitation decay in Photosystem I immobilized on glass surface Journal Article
In: Photosynthesis Research, vol. 136, no. 2, pp. 171-181, 2018, ISSN: 0166-8595.
Abstract | Links | BibTeX | Tagi:
@article{Szewczyk2018b,
title = {Acceleration of the excitation decay in Photosystem I immobilized on glass surface},
author = {Sebastian Szewczyk and Wojciech Giera and Rafał Białek and Gotard Burdziński and Krzysztof Gibasiewicz},
url = {http://link.springer.com/10.1007/s11120-017-0454-z},
doi = {10.1007/s11120-017-0454-z},
issn = {0166-8595},
year = {2018},
date = {2018-05-01},
journal = {Photosynthesis Research},
volume = {136},
number = {2},
pages = {171-181},
abstract = {textcopyright 2017 The Author(s) Femtosecond transient absorption was used to study excitation decay in monomeric and trimeric cyanobacterial Photosystem I (PSI) being prepared in three states: (1) in aqueous solution, (2) deposited and dried on glass surface (either conducting or non-conducting), and (3) deposited on glass (conducting) surface but being in contact with aqueous solvent. The main goal of this contribution was to determine the reason of the acceleration of the excitation decay in dried PSI deposited on the conducting surface relative to PSI in solution observed previously using time-resolved fluorescence (Szewczyk et al., Photysnth Res 132(2):111–126, 2017). We formulated two alternative working hypotheses: (1) the acceleration results from electron injection from PSI to the conducting surface; (2) the acceleration is caused by dehydration and/or crowding of PSI proteins deposited on the glass substrate. Excitation dynamics of PSI in all three types of samples can be described by three main components of subpicosecond, 3–5, and 20–26 ps lifetimes of different relative contributions in solution than in PSI-substrate systems. The presence of similar kinetic components for all the samples indicates intactness of PSI proteins after their deposition onto the substrates. The kinetic traces for all systems with PSI deposited on substrates are almost identical and they decay significantly faster than the kinetic traces of PSI in solution. We conclude that the accelerated excitation decay in PSI-substrate systems is caused mostly by dense packing of proteins.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Giera, Wojciech; Szewczyk, Sebastian; McConnell, Michael D; Redding, Kevin E; van Grondelle, Rienk; Gibasiewicz, Krzysztof
Uphill energy transfer in photosystem I from Chlamydomonas reinhardtii. Time-resolved fluorescence measurements at 77 K Journal Article
In: Photosynthesis Research, vol. 137, no. 2, pp. 321-335, 2018, ISSN: 1573-5079.
Abstract | Links | BibTeX | Tagi:
@article{Giera2018,
title = {Uphill energy transfer in photosystem I from Chlamydomonas reinhardtii. Time-resolved fluorescence measurements at 77 K},
author = {Wojciech Giera and Sebastian Szewczyk and Michael D McConnell and Kevin E Redding and Rienk van Grondelle and Krzysztof Gibasiewicz},
url = {https://doi.org/10.1007/s11120-018-0506-z},
doi = {10.1007/s11120-018-0506-z},
issn = {1573-5079},
year = {2018},
date = {2018-01-01},
journal = {Photosynthesis Research},
volume = {137},
number = {2},
pages = {321-335},
abstract = {Energetic properties of chlorophylls in photosynthetic complexes are strongly modulated by their interaction with the protein matrix and by inter-pigment coupling. This spectral tuning is especially striking in photosystem I (PSI) complexes that contain low-energy chlorophylls emitting above 700 nm. Such low-energy chlorophylls have been observed in cyanobacterial PSI, algal and plant PSI--LHCI complexes, and individual light-harvesting complex I (LHCI) proteins. However, there has been no direct evidence of their presence in algal PSI core complexes lacking LHCI. In order to determine the lowest-energy states of chlorophylls and their dynamics in algal PSI antenna systems, we performed time-resolved fluorescence measurements at 77 K for PSI core and PSI--LHCI complexes isolated from the green alga Chlamydomonas reinhardtii. The pool of low-energy chlorophylls observed in PSI cores is generally smaller and less red-shifted than that observed in PSI--LHCI complexes. Excitation energy equilibration between bulk and low-energy chlorophylls in the PSI--LHCI complexes at 77 K leads to population of excited states that are less red-shifted (by textasciitildethinspace12 nm) than at room temperature. On the other hand, analysis of the detection wavelength dependence of the effective trapping time of bulk excitations in the PSI core at 77 K provided evidence for an energy threshold at textasciitildethinspace675 nm, above which trapping slows down. Based on these observations, we postulate that excitation energy transfer from bulk to low-energy chlorophylls and from bulk to reaction center chlorophylls are thermally activated uphill processes that likely occur via higher excitonic states of energy accepting chlorophylls.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2017
Szewczyk, Sebastian; Giera, Wojciech; D'Haene, Sandrine; van Grondelle, Rienk; Gibasiewicz, Krzysztof
Comparison of excitation energy transfer in cyanobacterial photosystem I in solution and immobilized on conducting glass Journal Article
In: Photosynthesis Research, vol. 132, no. 2, pp. 111–126, 2017, ISSN: 0166-8595.
@article{Szewczyk2017b,
title = {Comparison of excitation energy transfer in cyanobacterial photosystem I in solution and immobilized on conducting glass},
author = {Sebastian Szewczyk and Wojciech Giera and Sandrine D'Haene and Rienk van Grondelle and Krzysztof Gibasiewicz},
url = {http://link.springer.com/10.1007/s11120-016-0312-4},
doi = {10.1007/s11120-016-0312-4},
issn = {0166-8595},
year = {2017},
date = {2017-05-01},
journal = {Photosynthesis Research},
volume = {132},
number = {2},
pages = {111--126},
publisher = {Springer Netherlands},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2015
Adamiec, Małgorzata; Gibasiewicz, Krzysztof; Luciński, Robert; Giera, Wojciech; Chełminiak, Przemysław; Szewczyk, Sebastian; Sipińska, Weronika; van Grondelle, Rienk; Jackowski, Grzegorz
In: Journal of Photochemistry and Photobiology B: Biology, vol. 153, pp. 423–428, 2015, ISSN: 10111344.
Abstract | Links | BibTeX | Tagi:
@article{Adamiec2015,
title = {Excitation energy transfer and charge separation are affected in Arabidopsis thaliana mutants lacking light-harvesting chlorophyll a/b binding protein Lhcb3},
author = {Małgorzata Adamiec and Krzysztof Gibasiewicz and Robert Luciński and Wojciech Giera and Przemysław Chełminiak and Sebastian Szewczyk and Weronika Sipińska and Rienk van Grondelle and Grzegorz Jackowski},
url = {http://www.ncbi.nlm.nih.gov/pubmed/26562806 http://linkinghub.elsevier.com/retrieve/pii/S1011134415003619},
doi = {10.1016/j.jphotobiol.2015.11.002},
issn = {10111344},
year = {2015},
date = {2015-12-01},
journal = {Journal of Photochemistry and Photobiology B: Biology},
volume = {153},
pages = {423--428},
abstract = {The composition of LHCII trimers as well as excitation energy transfer and charge separation in grana cores of Arabidopsis thaliana mutant lacking chlorophyll a/b binding protein Lhcb3 have been investigated and compared to those in wild-type plants. In grana cores of lhcb3 plants we observed increased amounts of Lhcb1 and Lhcb2 apoproteins per PSII core. The additional copies of Lhcb1 and Lhcb2 are expected to substitute for Lhcb3 in LHCII trimers M as well as in the LHCII "extra" pool, which was found to be modestly enlarged as a result of the absence of Lhcb3. Time-resolved fluorescence measurements reveal a deceleration of the fast phase of excitation dynamics in grana cores of the mutant by ~15 ps, whereas the average fluorescence lifetime is not significantly altered. Monte Carlo modeling predicts a slowing down of the mean hopping time and an increased stabilization of the primary charge separation in the mutant. Thus our data imply that absence of apoprotein Lhcb3 results in detectable differences in excitation energy transfer and charge separation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gibasiewicz, Krzysztof; Adamiec, Małgorzata; Luciński, Robert; Giera, Wojciech; Chełminiak, Przemysław; Szewczyk, Sebastian; Sipińska, Weronika; Głów, Edyta; Karolczak, Jerzy; van Grondelle, Rienk; Jackowski, Grzegorz
Monte Carlo simulations of excitation and electron transfer in grana membranes Journal Article
In: Biochimica et Biophysica Acta (BBA) - Bioenergetics, vol. 1847, no. 3, pp. 314–327, 2015, ISSN: 00052728.
Abstract | Links | BibTeX | Tagi:
@article{Gibasiewicz2015,
title = {Monte Carlo simulations of excitation and electron transfer in grana membranes},
author = {Krzysztof Gibasiewicz and Małgorzata Adamiec and Robert Luciński and Wojciech Giera and Przemysław Chełminiak and Sebastian Szewczyk and Weronika Sipińska and Edyta Głów and Jerzy Karolczak and Rienk van Grondelle and Grzegorz Jackowski},
url = {http://www.ncbi.nlm.nih.gov/pubmed/25524819 http://linkinghub.elsevier.com/retrieve/pii/S0005272814006628},
doi = {10.1016/j.bbabio.2014.12.004},
issn = {00052728},
year = {2015},
date = {2015-03-01},
journal = {Biochimica et Biophysica Acta (BBA) - Bioenergetics},
volume = {1847},
number = {3},
pages = {314--327},
abstract = {Time-resolved fluorescence measurements on grana membranes with instrumental response function of 3 ps reveal faster excitation dynamics (120 ps) than those reported previously. A possible reason for the faster decay may be a relatively low amount of "extra" LHCII trimers per reaction center of Photosystem II. Monte Carlo modeling of excitation dynamics in C2S2M2 form of PSII-LHCII supercomplexes has been performed using a coarse grained model of this complex, constituting a large majority of proteins in grana membranes. The main factor responsible for the fast fluorescence decay reported in this work was the deep trap constituted by the primary charge separated state in the reaction center (950-1090 cm(-1)). This value is critical for a good fit, whereas typical hopping times between antenna polypeptides (from ~4.5 to ~10.5 ps) and reversible primary charge separation times (from ~4 to ~1.5 ps, respectively) are less critical. Consequently, respective mean migration times of excitation from anywhere in the PSII-LHCII supercomplexes to reaction center range from ~30 to ~80 ps. Thus 1/4-2/3 of the ~120-ps average excitation lifetime is necessary for the diffusion of excitation to reaction center, whereas the remaining time is due to the bottle-neck effect of the trap. Removal of 27% of the Lhcb6 apoprotein pool by mutagenesis of DEG5 gene caused the acceleration of the excitation decay from ~120 to ~100 ps. This effect may be due to the detachment of LHCII-M trimers from PSII-LHCII supercomplexes, accompanied by deepening of the reaction center trap.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2014
Giera, Wojciech; Szewczyk, Sebastian; McConnell, Michael D; Snellenburg, Joris; Redding, Kevin E; van Grondelle, Rienk; Gibasiewicz, Krzysztof
Excitation dynamics in Photosystem I from Chlamydomonas reinhardtii. Comparative studies of isolated complexes and whole cells Journal Article
In: Biochimica et Biophysica Acta (BBA) - Bioenergetics, vol. 1837, no. 10, pp. 1756–1768, 2014, ISSN: 00052728.
Abstract | Links | BibTeX | Tagi:
@article{Giera2014,
title = {Excitation dynamics in Photosystem I from Chlamydomonas reinhardtii. Comparative studies of isolated complexes and whole cells},
author = {Wojciech Giera and Sebastian Szewczyk and Michael D McConnell and Joris Snellenburg and Kevin E Redding and Rienk van Grondelle and Krzysztof Gibasiewicz},
url = {http://www.ncbi.nlm.nih.gov/pubmed/24973599 http://linkinghub.elsevier.com/retrieve/pii/S0005272814005192},
doi = {10.1016/j.bbabio.2014.06.004},
issn = {00052728},
year = {2014},
date = {2014-10-01},
journal = {Biochimica et Biophysica Acta (BBA) - Bioenergetics},
volume = {1837},
number = {10},
pages = {1756--1768},
abstract = {Identical time-resolved fluorescence measurements with ~3.5-ps resolution were performed for three types of PSI preparations from the green alga, Chlamydomonas reinhardtii: isolated PSI cores, isolated PSI-LHCI complexes and PSI-LHCI complexes in whole living cells. Fluorescence decay in these types of PSI preparations has been previously investigated but never under the same experimental conditions. As a result we present consistent picture of excitation dynamics in algal PSI. Temporal evolution of fluorescence spectra can be generally described by three decay components with similar lifetimes in all samples (6-8ps, 25-30ps, 166-314ps). In the PSI cores, the fluorescence decay is dominated by the two fastest components (~90%), which can be assigned to excitation energy trapping in the reaction center by reversible primary charge separation. Excitation dynamics in the PSI-LHCI preparations is more complex because of the energy transfer between the LHCI antenna system and the core. The average trapping time of excitations created in the well coupled LHCI antenna system is about 12-15ps longer than excitations formed in the PSI core antenna. Excitation dynamics in PSI-LHCI complexes in whole living cells is very similar to that observed in isolated complexes. Our data support the view that chlorophylls responsible for the long-wavelength emission are located mostly in LHCI. We also compared in detail our results with the literature data obtained for plant PSI.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2013
Sikora, Bożena; Fronc, Krzysztof; Kamińska, Izabela; Koper, Kamil; Szewczyk, Sebastian; Paterczyk, Bohdan; Wojciechowski, Tomasz; Sobczak, Kamil; Minikayev, Roman; Paszkowicz, Wojciech; Stępień, Piotr; Elbaum, Danek
Transport of NaYF4:Er3+, Yb3+ up-converting nanoparticles into HeLa cells Journal Article
In: Nanotechnology, vol. 24, no. 23, pp. 235702, 2013.
Abstract | Links | BibTeX | Tagi:
@article{Sikora2013,
title = {Transport of NaYF_{4}:Er^{3+}, Yb^{3+} up-converting nanoparticles into HeLa cells},
author = {Bożena Sikora and Krzysztof Fronc and Izabela Kamińska and Kamil Koper and Sebastian Szewczyk and Bohdan Paterczyk and Tomasz Wojciechowski and Kamil Sobczak and Roman Minikayev and Wojciech Paszkowicz and Piotr Stępień and Danek Elbaum},
url = {http://stacks.iop.org/0957-4484/24/i=23/a=235702},
doi = {10.1088/0957-4484/24/23/235702},
year = {2013},
date = {2013-01-01},
journal = {Nanotechnology},
volume = {24},
number = {23},
pages = {235702},
abstract = {An effective, simple and practically useful method to incorporate fluorescent nanoparticles inside live biological cells was developed. The internalization time and concentration dependence of a frequently used liposomal transfection factor (Lipofectamine 2000) was studied. A user friendly, one-step technique to obtain water and organic solvent soluble Er 3+ and Yb 3+ doped NaYF 4 nanoparticles coated with polyvinylpyrrolidone was obtained. Structural analysis of the nanoparticles confirmed the formation of nanocrystals of the desired sizes and spectral properties. The internalization of NaYF 4 nanoparticles in HeLa cervical cancer cells was determined at different nanoparticle concentrations and for incubation periods from 3 to 24 h. The images revealed a redistribution of nanoparticles inside the cell, which increases with incubation time and concentration levels, and depends on the presence of the transfection factor. The study identifies, for the first time, factors responsible for an effective endocytosis of the up-converting nanoparticles to HeLa cells. Thus, the method could be applied to investigate a wide range of future ‘smart’ theranostic agents. Nanoparticles incorporated into the liposomes appear to be very promising fluorescent probes for imaging real-time cellular dynamics.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}