Crystal fields in ROF:Tb3+ (R = La, Gd)

Antić-Fidančev, E.; Hölsä, Jorma; Krupa, J.C.; Lastusaari, Mika

doi:10.1016/j.jallcom.2004.03.058

Cited by 23 publications

(9 citation statements)

References 21 publications

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“…67 Extensive ligand field splitting of ground-and excited-state energy levels of this transition gives rise to multiple overlapping peaks that cannot be resolved in solution. 57,68,69 Similarly, the steady-state excitation spectra of aqueous solutions of Sm(EDTA), Sm(DTPA), Sm(III) aqua ion, Dy(EDTA), Dy(DTPA), and Dy(III) aqua ion were collected at 0.1 nm steps. The excitation transitions 6 H 5/2 !…”

Section: Resultsmentioning

confidence: 99%

Spectroscopic System for Direct Lanthanide Photoluminescence Spectroscopy with Nanomolar Detection Limits

et al. 2009

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A new spectroscopic system for direct photoluminescence of lanthanide ions (Ln(III)) through electronic transitions within the 4f(n) manifold is described. The system is based on an injection seeded frequency tripled (lambda = 355 nm) Nd:YAG pump laser coupled with a master oscillator power oscillator (MOPO). The MOPO delivers an average pulse energy of approximately 60 mJ/pulse, is continuously tunable from 425 to 690 nm (Signal) and 735 to 1800 nm (Idler) with a linewidth of <0.2 cm(-1), and has a pulse duration of 10-12 ns. Aqueous solutions containing two polyaminocarboxylate complexes, ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA), and Ln(3+) aqua ion for several lanthanides including Eu(III), Tb(III), Dy(III), and Sm(III)) are used as steady-state and time-resolved photoluminescence standards. The versatility of the instrument is demonstrated by excitation scans over a broad visible range for aqueous solutions of complexes of Eu(III), Dy(III), Sm(III), and Tb(III). The Eu(III) excitation band ((7)F(o)-->(5)D(o)) is recorded over a range of complex concentrations that are 1000-fold less than reported previously, including Eu(EDTA) (1.00 nM), Eu(DTPA) (1.00 nM), and Eu(III) aqua ion (50.0 nM). Emission spectra are recorded in the visible range for Ln(III) complexes at pH 6.5 and 1.00 mM. Excited-state lifetimes for the standards were constant as a function of concentration from 10.0 nM to 1.00 mM for Eu(EDTA) and Eu(DTPA) and from 100 nM to 1.00 mM for Eu(III) aqua ion. Photoluminescence lifetimes in H(2)O and D(2)O are recorded and used to calculate the number of bound water molecules for all complexes.

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Section: Resultsmentioning

confidence: 99%

Spectroscopic System for Direct Lanthanide Photoluminescence Spectroscopy with Nanomolar Detection Limits

et al. 2009

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“…The research in the area of rare earth oxyfluorides (REOF) is thriving not only through the rich structural varieties observed in the materials but also through their widely varying luminescence properties that promise potential applications. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] The structural properties of REOF were mostly investigated by Zachariasen in the 1950s. 16 It has been determined that as a result of solid state reaction between rare earth fluorides and their oxides at high temperatures, oxyfluorides are formed.…”

Section: Introductionmentioning

confidence: 99%

Revised crystal structure and luminescent properties of gadolinium oxyfluoride Gd₄O₃F₆doped with Eu³⁺ions

et al. 2014

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The structure of gadolinium oxyfluoride nanoparticles was revised. Extensive studies including X-ray diffraction and Rietveld refinement as well as Fourier transform infrared spectroscopy and Raman spectroscopy confirmed the monoclinic P12/c1 crystal structure of Gd4O3F6. Morphological analysis using transmission electron microscopy showed the nanocrystallinity of the materials prepared via the sol-gel Pechini's method. The luminescent properties of the prepared materials with different concentrations of Eu(3+) ions were characterized by emission spectroscopy. The phosphors obtained were investigated in the vacuum ultraviolet range using synchrotron radiation. The Judd-Ofelt parameters (Ω2, Ω4) and emission efficiencies η were calculated and are discussed in detail.

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“…The energy gaps between the 5 D 4 and 7 F 4 / 7 F 3 / 7 F 2 / 7 F 1 / 7 F 0 levels in Tb 3+ ion amount to 16 957/ 16 291/15 437/15 166/14 900 cm −1 , respectively. 28 These energy gaps are smaller than five times of the maximum phonon energy of DOX (3528 cm −1 ). Therefore, the relaxation of the excited electrons from 5 D 4 level to the lower 7 F 4 / 7 F 3 / 7 F 2 / 7 F 1 / 7 F 0…”

Section: In Vitro Cytotoxicity and Drug Release Behaviorsmentioning

confidence: 92%

Core–shell structured luminescent and mesoporous β-NaYF4:Ce3+/Tb3+@mSiO2-PEG nanospheres for anti-cancer drug delivery

Yang

Kang

et al. 2013

Dalton Trans.

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Multifunctional nanocomposites integrating mesoporous and luminescence properties into a single entity are synthesized via a facile and effective approach. Oleic acid capped β-NaYF4:Ce(3+)/Tb(3+) nanoparticles (NPs) are transferred into aqueous solution by cetyltrimethylammonium bromide (CTAB) surfactants, and further encapsulated with uniform mesoporous silica shell followed by the surface modification with poly(ethylene glycol) (PEG), leading to the formation of water-dispersible and biocompatible core-shell structured β-NaYF4:Ce(3+)/Tb(3+)@mSiO2-PEG (denoted as NPs@mSiO2-PEG) nanospheres. The as-synthesized nanospheres show a typical mesoporous structure and a green emission under UV irradiation. Doxorubicin hydrochloride (DOX), a widely used anti-cancer drug, is used as a model drug to evaluate the loading and controlled release behaviors of the NPs@mSiO2-PEG in phosphoric acidic buffer solutions (PBS) at different pH values (pH = 7.4 and 5.0). The composite carriers provide a pH-sensitive drug release pattern and the drug releases faster under lower pH value. The endocytosis process of fluorescein isothiocyanate (FITC)-labelled nanospheres is characterized using flow cytometry and confocal laser scanning microscopy (CLSM) against A549 cells. The in vitro cytotoxic effect against A549 cells of the DOX-loaded carriers is investigated in detail. In addition, the extent of drug release can be monitored by the variation of photoluminescence (PL) intensity of β-NaYF4:Ce(3+)/Tb(3+). Considering the good biocompatibility and pH-dependent drug release pattern, such core-shell structured luminescent NPs@mSiO2-PEG nanospheres have potential applications in controlled drug delivery.

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Crystal fields in ROF:Tb3+ (R = La, Gd)

Cited by 23 publications

References 21 publications

Spectroscopic System for Direct Lanthanide Photoluminescence Spectroscopy with Nanomolar Detection Limits

Spectroscopic System for Direct Lanthanide Photoluminescence Spectroscopy with Nanomolar Detection Limits

Revised crystal structure and luminescent properties of gadolinium oxyfluoride Gd₄O₃F₆doped with Eu³⁺ions

Core–shell structured luminescent and mesoporous β-NaYF4:Ce3+/Tb3+@mSiO2-PEG nanospheres for anti-cancer drug delivery

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Crystal fields in ROF:Tb3+ (R = La, Gd)

Cited by 23 publications

References 21 publications

Spectroscopic System for Direct Lanthanide Photoluminescence Spectroscopy with Nanomolar Detection Limits

Spectroscopic System for Direct Lanthanide Photoluminescence Spectroscopy with Nanomolar Detection Limits

Revised crystal structure and luminescent properties of gadolinium oxyfluoride Gd4O3F6doped with Eu3+ions

Core–shell structured luminescent and mesoporous β-NaYF4:Ce3+/Tb3+@mSiO2-PEG nanospheres for anti-cancer drug delivery

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Revised crystal structure and luminescent properties of gadolinium oxyfluoride Gd₄O₃F₆doped with Eu³⁺ions