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Gilded nanoparticles for plasmonically enhanced fluorescence in TiO2:Sm3+ sol-gel films.

Pikker S, Dolgov L, Heinsalu S, Mamykin S, Kiisk V, Kopanchuk S, Lõhmus R, Sildos I - Nanoscale Res Lett (2014)

Bottom Line: Local enhancement of Sm3+ fluorescence in the vicinity of separate gilded nanoparticles was revealed by a combination of dark field microscopy and fluorescence spectroscopy techniques.An intensity enhancement of Sm3+ fluorescence varies from 2.5 to 10 times depending on the used direct (visible) or indirect (ultraviolet) excitations.Analysis of fluorescence lifetimes suggests that the locally stronger fluorescence occurs because of higher plasmon-coupled direct absorption of exciting light by the Sm3+ ions or due to plasmon-assisted non-radiative energy transfer from the excitons of TiO2 host to the rare earth ions. 78; 78.67.-n; 78.67.Bf.

View Article: PubMed Central - HTML - PubMed

Affiliation: V, Lashkaryov Institute of Semiconductor Physics of National Academy of Sciences of Ukraine, Kyiv 03680, Ukraine. smamykin@gmail.com.

ABSTRACT

Unlabelled: Silica-gold core-shell nanoparticles were used for plasmonic enhancement of rare earth fluorescence in sol-gel-derived TiO2:Sm3+ films. Local enhancement of Sm3+ fluorescence in the vicinity of separate gilded nanoparticles was revealed by a combination of dark field microscopy and fluorescence spectroscopy techniques. An intensity enhancement of Sm3+ fluorescence varies from 2.5 to 10 times depending on the used direct (visible) or indirect (ultraviolet) excitations. Analysis of fluorescence lifetimes suggests that the locally stronger fluorescence occurs because of higher plasmon-coupled direct absorption of exciting light by the Sm3+ ions or due to plasmon-assisted non-radiative energy transfer from the excitons of TiO2 host to the rare earth ions.

Pacs: 78; 78.67.-n; 78.67.Bf.

No MeSH data available.


SEM image (a) and light extinction spectra (b) of spherical gilded nanoparticles.
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Figure 1: SEM image (a) and light extinction spectra (b) of spherical gilded nanoparticles.

Mentions: Silica-gold core-shell nanoparticles were initially prepared as dispersion in water. For scanning electron microscopy (SEM) characterization, the droplets of this dispersion were deposited on a silicon substrate and dried. SEM images indicate globules with a narrow size distribution (Figure 1a). The size of silica core approximately 140 nm and thickness of the gold shell approximately 15 to 20 nm were estimated on the basis of several SEM images. Plasmonic properties of these nanoparticles become apparent already during the synthesis process because the spectrally selective plasmonic light absorption lead to a bluish color of the prepared dispersion. Light extinction spectra measured for the 1-cm layer of this dispersion consists of two bands with maxima at 525 and 675 nm (Figure 1b, curve 1). The shapes of these bands are related respectively to the quadrupole and dipole plasmonic resonances calculated according to the Mie theory (Figure 1b, curve 2).


Gilded nanoparticles for plasmonically enhanced fluorescence in TiO2:Sm3+ sol-gel films.

Pikker S, Dolgov L, Heinsalu S, Mamykin S, Kiisk V, Kopanchuk S, Lõhmus R, Sildos I - Nanoscale Res Lett (2014)

SEM image (a) and light extinction spectra (b) of spherical gilded nanoparticles.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3973191&req=5

Figure 1: SEM image (a) and light extinction spectra (b) of spherical gilded nanoparticles.
Mentions: Silica-gold core-shell nanoparticles were initially prepared as dispersion in water. For scanning electron microscopy (SEM) characterization, the droplets of this dispersion were deposited on a silicon substrate and dried. SEM images indicate globules with a narrow size distribution (Figure 1a). The size of silica core approximately 140 nm and thickness of the gold shell approximately 15 to 20 nm were estimated on the basis of several SEM images. Plasmonic properties of these nanoparticles become apparent already during the synthesis process because the spectrally selective plasmonic light absorption lead to a bluish color of the prepared dispersion. Light extinction spectra measured for the 1-cm layer of this dispersion consists of two bands with maxima at 525 and 675 nm (Figure 1b, curve 1). The shapes of these bands are related respectively to the quadrupole and dipole plasmonic resonances calculated according to the Mie theory (Figure 1b, curve 2).

Bottom Line: Local enhancement of Sm3+ fluorescence in the vicinity of separate gilded nanoparticles was revealed by a combination of dark field microscopy and fluorescence spectroscopy techniques.An intensity enhancement of Sm3+ fluorescence varies from 2.5 to 10 times depending on the used direct (visible) or indirect (ultraviolet) excitations.Analysis of fluorescence lifetimes suggests that the locally stronger fluorescence occurs because of higher plasmon-coupled direct absorption of exciting light by the Sm3+ ions or due to plasmon-assisted non-radiative energy transfer from the excitons of TiO2 host to the rare earth ions. 78; 78.67.-n; 78.67.Bf.

View Article: PubMed Central - HTML - PubMed

Affiliation: V, Lashkaryov Institute of Semiconductor Physics of National Academy of Sciences of Ukraine, Kyiv 03680, Ukraine. smamykin@gmail.com.

ABSTRACT

Unlabelled: Silica-gold core-shell nanoparticles were used for plasmonic enhancement of rare earth fluorescence in sol-gel-derived TiO2:Sm3+ films. Local enhancement of Sm3+ fluorescence in the vicinity of separate gilded nanoparticles was revealed by a combination of dark field microscopy and fluorescence spectroscopy techniques. An intensity enhancement of Sm3+ fluorescence varies from 2.5 to 10 times depending on the used direct (visible) or indirect (ultraviolet) excitations. Analysis of fluorescence lifetimes suggests that the locally stronger fluorescence occurs because of higher plasmon-coupled direct absorption of exciting light by the Sm3+ ions or due to plasmon-assisted non-radiative energy transfer from the excitons of TiO2 host to the rare earth ions.

Pacs: 78; 78.67.-n; 78.67.Bf.

No MeSH data available.