XIV
h
International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
256
T3: P–2
Hollow Au@Ag@SiO
2
core-shell nanoparticles
as new type of nanoresonators for shell-isolated
nanoparticle-enhanced Raman spectroscopy
Karol Kołątaj
1
, Jan Krajczewski
1
, and Andrzej Kudelski
1
1
Department of Chemistry, University of Warsaw, Ludwika Pasteura 1, Warsaw, Poland,
e-mail: kkolataj@chem.uw.edu.pl
SHINERS measurements were introduced by Tian et al. in 2010 as the new approach to
analyze various surfaces 1. In this method Raman spectrum was measured from an investigated
substrate covered with gold nanoparticles protected by a thin layer of silica or alumina. Gold
nanoparticles act as electromagnetic nanoresonators, significantly enhancing electric field of the
incident electromagnetic radiation and hence leading to large increase of the Raman signal from
studied surface. The inert shell separates metal cores from direct contact with probed molecules
and keeps them from agglomeration. Therefore, such systems might find more analytical
applications, also for living cells. In this work, we present the synthesis of hollow
Au@Ag@SiO
2
core shell nanoparticles as the new type of SHINERS nanoresonators.
The synthesis of Au@Ag@SiO
2
nanoparticles, we firstly obtained hollow gold nanoparticles
according to a modified Moshe and Markovich method 2. Obtained hollow gold nanoparticles
were then covered with silver layer using method developed by Wang 3. Deposition of thin
silica layer on obtained hollow Au@Ag nanoparticles was carried out by the hydrolysis of
tetraethoxysilane catalyzed by ammonium solution 4. Synthesized hollow Au@Ag@SiO
2
nanoparticles were presented in Fig. 1.
Fig. 1. TEM micrograph of synthesized Au@Ag@SiO
2
nanoparticles.
Obtained hollow core-shell nanoparticles were afterwards successfully used as
nanoresonators in
Raman
measurements
of
4-mercaptobenzoic
acid and
2-
mercaptoethanesulfonate. We observed that obtained Au@Ag nanoresonators showed
approximately 120 times stronger Raman signal than hollow Au nanoparticles before silver
deposition.
Keywords: SERS; SHINERS; nanoparticles
References
[1] Li J. F., Huang Y. F., Ding Y., Yang Z. L., Li S. B., Zhou X. S., Fan F. R., Zhang W., Zhou Z. Y., Wu
D. Y., Ren B., Wang Z. L. and Z. Q, Nature 46 (2010) 392.
[2] Moshe A. B.; Markovich G. Chem. Mater. 23 (2011) 1239.
[3] Ma P.; Liang F.; Diao Q; Wang D.; Yang Q.; Gao D.; Song D.; Wang X. RSC Adv. 5 (2015) 32168.
[4] Shanthil M.; Thomas R.; Swathi R.S.; Thomas G. J. Phys. Chem. Lett.. 3 (2012) 1459.
XIV
h
International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
257
T3: P–3
Influence of stoichiometry on properties and femtosecond laser
modification ability of As-Se-Te chalcogenide films
Leonid Mochalov
1,3
, Aleksey Nezhdanov
1
, Mhikhail Kudryashov
1
,
Alexandr Logunov
1
, Dominik Dorosz
2
, Giuseppe Chidichimo
4
,
Giovanni De Filpo
4
, and Aleksandr Mashin
1
1
Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia,
e-mail: mochalovleo@gmail.com
2
Faculty of Materials Science and Ceramics, AGH University of Science and Technology,
Krakow, Poland
3
Nizhny Novgorod State Technical University n.a. R.E. Alekseev, Nizhny Novgorod, Russia
4
University of Calabria, P. Bucci-15c, Rende (CS), Italy
The samples of ternary chalcogenide system As-Se-Te films of different stoichiometry have
been prepared by PECVD from corresponding volatile elements [1–3]. Raman spectra the film
samples are shown in Fig. 1a. All the spectra display a few broad bands relating to the vibration
of units of structural net containing Te-Te (160 сm
–1
), As-Te (197 сm
–1
), As-Se (227 сm
–1
), and
As-Se (about 244 cm
–1
) bonds. A broad band with a peak about 227 cm
–1
corresponds to the
vibrations of AsSe
3/2
structural units in the glass net enriched with Se, when the excess Se is in
the form of Se
8
rings. If the concentration of As increases, the band becomes wider and a band
near 244 cm
–1
related to vibration of AsSe
3/2
pyramids and connected through arsenic atom
appears. The IR transmission spectra are shown in Fig. 1b. The films possess a high degree of
transparency in the range 1–12 microns.
Fig. 1. Raman spectra (a) and IR transparency (b) and laser modification (c) of As-Se- Te films.
The obtained films were modified by femtosecond laser irradiation. Linearly polarized
femtosecond laser radiation (pulse duration 60 fs, wavelength 800 nm, and pulse energy up to 10
mJ) was focused by a conical axicon lens with a base angle of 25 into the depth of the samples
with thickness 10 microns. The results of modification are presented in Fig. 1c.
Keywords: As-Se-Te system; PECVD; molecular spectroscopy
Acknowledgment
This work was supported by the Russian Science Foundation grant 16-12-00038.
References
[1] L. Mochalov, A. Nezhdanov, M. Kudryashov, et al., Plasma Chem. Plasma P. (2017).
doi:10.1007/s11090-017-9830-xA.
[2] L. Mochalov, A. Nezhdanov, M. Kudryashov, et al., Superlattice. Microst. (2017). doi:
10.1016/j.spmi.2017.06.030.
[3] L. Mochalov, A. Nezhdanov, et al., J. Opt. Quant. Electron. (2017). doi: 10.1007/s11082-017-1117-1.
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