Download Comparison of DNA damage by subionized and ionized energy electron collisions and novel component separable nonthermal atmospheric plasma

22nd International Symposium on Plasma Chemistry
July 5-10, 2015; Antwerp, Belgium
Comparison of DNA damage by sub-ionized and ionized energy electron
collisions and novel component separable nonthermal atmospheric plasma
Y. Park1, H. Noh2, H. Cho2, S. Leon3 and R. Wagner3
1
Plasma Technology Research Center, National Fusion Research Institute, Gunsan, South Korea
2
Department of Physics, Chungnam National University, Daejeon, South Korea
3
Université de Sherbrooke, Sherbrooke J1H 5N4, Québec, Canada
Abstract: Low energy electrons (LEEs) under 15 eV can indirectly damage DNA subunits
via dissociative electron attachment (DEA). We have compared DNA damage induced by
LEE and high energy electron (HEE) collisions. We have also tried XPS analysis to clearly
interpret the exact mechanism of DNA damage by LEE. Finally, we introduce a new
design of nonthermal atmospheric plasma source to investigate plasma effects of plasma
agriculture and food applications.
Keywords: DNA damage, dissociative electron attachment, plasma jet, XPS analysis
1. Introduction
It is very interesting that LEE can generate DNA
damage by resonant mechanism even they have not
enough energy to cause direct ionization [1]. We have
studied the exact damage mechanism by LEE and other
causes like UV, radical and ions at the molecular level.
We will introduce some results and would like to discuss
them with you to further understand. And we are
planning to make a new experimental system to
investigate plasma effects of plasma based agriculture and
food applications.
2. Experiment
The dried DNA films through the lyophilized technique
were irradiated by LEE (1 eV and 10 eV) and HEE
(10 keV) under ultra-high vacuum.
And then, the
irradiated DNA samples were analysed with HPLC, LC
MS/MS and XPS to compare the yield of DNA damage
and find out new types of DNA damage.
3. Results and discussion
We confirm that LEEs can indirectly generate DNA
damage through DEA resonant process and HEE can
directly generate DNA damage through one electron
ionization. Fig. 1 shows HPLC chromatogram of 1 eV
electron collision and control. We observed many new
types of DNA damage with 1 eV, 10 eV and 10 keV
electron collisions. Fig. 2 shows the comparison of XPS
spectra. The change of C1s peaks may be related to the
damage of bonds such as C-C, C-N, C-H on DNA
subunits. Peaks in C1s region are increased or decreased
after LEE collision and adding Fe ion.
0,007
TpT
0,005
0,003
0,002
TpTp
pTpT
Thy
pT
0,004
Tp
Absorption at 260 nm (a.u.)
TpTpT
(1) TpTpT(1 eV irradiation)
(2) TpTpT(No 1 eV irradiation)
(a)
0,006
(1)
0,001
0,000
(2)
0
10
20
30
40
50
60
70
Retention time (min)
Fig. 1. HPLC chromatograms of (1) 1 eV electron
collision on DNA and (2) control.
(a
(b)
C1s Scan A
C1s Scan A
C1s
C1s
C1s Scan B
C1s Scan B
C1s Scan C
(c
)
C1s Scan C
C1s Scan A
C1s
(d)
C1s Scan A
C1s Scan B
C1s
C1s Scan B
C1s Scan C
C1s Scan C
Fig. 2. XPS spectra of C1s region for DNA film samples:
(a) DNA without LEE and Fe ion; (b) DNA with LEE
only; (c) DNA without LEE and with Fe ion; and (d)
DNA with LEE and Fe ion.
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4. Conclusion
We have compared DNA damage by LEE and HEE
collisions. And we also tried XPS analysis of DNA
damage to further investigate of DNA damaging
mechanism. We introduce a novel component separable
nonthermal atmospheric plasma source.
5. References
[1] B. Boudaiffa, et al. Science, 287, 1658 (2000)
2
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