Intense infrared upconversion luminescence of NaGdF4:Yb/Tm with controlled intensity

Inorganic nanomaterials able to generate reactive oxygen species (ROS) are promising components for modern medical applications. Activated by near-infrared light, up-converting b-NaYF 4 doped with Er 3+ -Yb 3+ and Tm 3+ -Yb 3+ pair ions nanoparticles (UCNPs), have a wide range of applications in biological imaging as compared to traditional reagents excited by ultra-violet or visible light. We analysed the green-red and the blue-red luminescence to explain the mechanism of the upconversion depended on the surface condition. The influence of SiO 2 coating on the cytotoxicity of the as-produced UCNPs towards HeLa cancer cells was reported. We demonstrated a possibility of a direct UCNPs application to photodynamic therapy, without need to attach additional molecules to their surface. The presence of Tm 3+ -Yb 3+ pair ions, thus ROS generation capability, renders the SiO 2 shell coated nanoparticles to become potentially useful theranostic agent.

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“…6). 52,53 As shown in Fig. 5a and e presence of the SiO 2 shell, has an impact to the physical aspect of the luminescence.…”

Section: Resultsmentioning

confidence: 89%

“…The energy level diagrams of the Er 3+ , Tm 3+ and Yb 3+ dopant ions and the corresponding upconversion mechanisms under 980 nm excitation. The ET interrupted arrows represent energy transfer (nonradiative transition), EXexcitation and EMemission of visible photons (radiative transition) [51][52][53]. …”

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confidence: 99%

Upconversion fluorescence imaging of HeLa cells using ROS generating SiO₂-coated lanthanide-doped NaYF₄ nanoconstructs

et al. 2017

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“…Recently, Yb 3+ and Tm 3+ co‐doped UC phosphors emitting a highly intense NIR light have attracted significant attention owing to their advantages for bioapplications. The NIR UC phosphors can diminish the autofluorescence background, leading to a high contrast in bioimaging ( in vivo and in vitro ) . In order to enhance the UC efficiency (strong UC emission), various methods have been suggested including cation substitutions, use of ultra‐small nanoparticles, and core/shell nanoparticles .…”

Section: Introductionmentioning

confidence: 99%

Enhancement of near‐infrared up‐conversion and blue down‐conversion luminescence in LuNbO₄:Yb³⁺,Tm³⁺ with Ga³⁺ and Ta⁵⁺ substitutions

Kim

2019

Luminescence

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Under a 980-nm excitation, the up-conversion (UC) spectra of LuNbO 4 :Yb 3+ ,Tm 3+ powders exhibited predominantly near-infrared bands (~805 nm) of Tm 3+ through an energy transfer process from Yb 3+ to Tm 3+ . Regarding the down-conversion (DC) luminescence of the powders, the photoluminescence excitation spectra consisted of a broad charge transfer band (270 nm) due to [NbO 4 ] 3− and sharp band (360 nm) of Tm 3+ , while the corresponding emission spectra exhibited a blue emission at 458 nm. Upon substitution of Ga 3+ and Ta 5+ for Lu 3+ and Nb 5+ , respectively, both UC and DC luminescence properties were significantly enhanced. For the Ga 3+ substitution, the increased emission intensity could be explained by the crystal field asymmetry surrounding the Tm 3+ ions induced by the large difference in ionic radius between Ga 3+ and Lu 3+ . For the Ta 5+ substitution, we believe that an M′-LuTaO 4 substructure was formed in the host, which led to the formation of a TaO 6 octahedral coordination instead of a NbO 4 tetrahedral coordination. Consequently, the crystal symmetry of the local structure was modified, and thus the UC and DC luminescence properties were enhanced. The dual-mode (UC and DC) luminescence demonstrates that LuNbO 4 :Yb 3+ ,Tm 3+ has a great potential in the fields of temperature sensing probes, anti-counterfeiting, and bioapplications.

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“…5 Currently reported upconversion materials includes NaYF 4 :Yb:Er nanoparticles doped with Gd 3+ and core−shell structures of NaGdF 4 :Yb/Tm. 6,7 There are also few illustrations on Ln 3+ -substituted apatite systems for upconversion luminescence and bioimaging. 8 Several carrier host systems are reported for utility in imaging-guided therapy and there is a thrust to develop multimodal imaging contrast agents.…”

Section: ■ Introductionmentioning

confidence: 99%

“…In the context of upconversion materials, NaYF 4 :Yb/Er upconversion nanophosphors have been developed for bioimaging and real time tracking . Currently reported upconversion materials includes NaYF 4 :Yb:Er nanoparticles doped with Gd 3+ and core–shell structures of NaGdF 4 :Yb/Tm. , There are also few illustrations on Ln 3+ -substituted apatite systems for upconversion luminescence and bioimaging …”

Section: Introductionmentioning

confidence: 99%

Cosubstitution of Lanthanides (Gd³⁺/Dy³⁺/Yb³⁺) in β-Ca₃(PO₄)₂ for Upconversion Luminescence, CT/MRI Multimodal Imaging

Meenambal

Kannan

2017

ACS Biomater. Sci. Eng.

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Multifunctional Gd 3+ , Dy 3+ and Yb 3+ cosubstitutions in β-Ca 3 (PO 4 ) 2 were achieved through a facile synthetic technique. Gd 3+ and Dy 3+ prefer to occupy the 7-fold coordinated Ca 2+ (1), 6-or 8-fold coordinated Ca 2+ (2), and 8-fold coordinated Ca 2+ (3) sites of the β-Ca 3 (PO 4 ) 2 structure. The shortest Ca(5)O bond length of te Ca 2+ (5) site with 6-fold co-ordination favors Yb 3+ accommodation. The substitution limit of each dopant to attain β-Ca 3 (PO 4 ) 2 solid solution is determined as ∼1.25 mol %. The combined substitutions displayed upconversion emission in blue, yellow and red regions on excitation at 980 nm via the energy transfer mechanism from Yb 3+ to Dy 3+ . Yb 3+ and Dy 3+ combination induces a high X-ray absorption ability for computed tomography (CT). The materials also displayed paramagnetic behavior and exhibited high longitudinal (r 1 = 48.71 mM −1 s −1 ) and transverse relaxivity (r 2 = 61.79 mM −1 s −1 ) indicating their potential as T 1 and T 2 contrast agents in magnetic resonance imaging (MRI). The negligible toxicity of Gd 3+ /Dy 3+ /Yb 3+ cosubstitutions in β-Ca 3 (PO 4 ) 2 is also demonstrated. The overall results justify the potential of the developed material as possible contrast agent for T 1 and T 2 MRI/ CT/upconversion luminescence.

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Intense infrared upconversion luminescence of NaGdF4:Yb/Tm with controlled intensity

Cited by 13 publications

References 19 publications

Upconversion fluorescence imaging of HeLa cells using ROS generating SiO₂-coated lanthanide-doped NaYF₄ nanoconstructs

Upconversion fluorescence imaging of HeLa cells using ROS generating SiO₂-coated lanthanide-doped NaYF₄ nanoconstructs

Enhancement of near‐infrared up‐conversion and blue down‐conversion luminescence in LuNbO₄:Yb³⁺,Tm³⁺ with Ga³⁺ and Ta⁵⁺ substitutions

Cosubstitution of Lanthanides (Gd³⁺/Dy³⁺/Yb³⁺) in β-Ca₃(PO₄)₂ for Upconversion Luminescence, CT/MRI Multimodal Imaging

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Intense infrared upconversion luminescence of NaGdF4:Yb/Tm with controlled intensity

Cited by 13 publications

References 19 publications

Upconversion fluorescence imaging of HeLa cells using ROS generating SiO2-coated lanthanide-doped NaYF4 nanoconstructs

Upconversion fluorescence imaging of HeLa cells using ROS generating SiO2-coated lanthanide-doped NaYF4 nanoconstructs

Enhancement of near‐infrared up‐conversion and blue down‐conversion luminescence in LuNbO4:Yb3+,Tm3+ with Ga3+ and Ta5+ substitutions

Cosubstitution of Lanthanides (Gd3+/Dy3+/Yb3+) in β-Ca3(PO4)2 for Upconversion Luminescence, CT/MRI Multimodal Imaging

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Upconversion fluorescence imaging of HeLa cells using ROS generating SiO₂-coated lanthanide-doped NaYF₄ nanoconstructs

Upconversion fluorescence imaging of HeLa cells using ROS generating SiO₂-coated lanthanide-doped NaYF₄ nanoconstructs

Enhancement of near‐infrared up‐conversion and blue down‐conversion luminescence in LuNbO₄:Yb³⁺,Tm³⁺ with Ga³⁺ and Ta⁵⁺ substitutions

Cosubstitution of Lanthanides (Gd³⁺/Dy³⁺/Yb³⁺) in β-Ca₃(PO₄)₂ for Upconversion Luminescence, CT/MRI Multimodal Imaging