Highly uniform up-converting nanoparticles: Why you should control your synthesis even more

Palo, Emilia; Tuomisto, Minnea; Hyppänen, Iko; Swart, H.C.; Hölsä, Jorma; Soukka, Tero; Lastusaari, Mika

doi:10.1016/j.jlumin.2016.12.051

Cited by 29 publications

(34 citation statements)

References 39 publications

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“…2, indicating a two-photon process, as expected ( Table S3 ). With the red emission, the slopes were generally higher than those previously achieved with oleic acid-capped materials 13 , 46 and in some of the materials raised as high as ca. 2.5.…”

Section: Resultscontrasting

confidence: 56%

“… 7 − 9 Especially, the research in the biomedical field has benefitted from the extensive development of upconversion material syntheses, resulting in nanoscale materials down to 5 nm. 10 − 13 Currently, hexagonal β-NaYF 4 :Yb 3+ ,Er 3+ is considered to be the most efficient material in upconversion. 14 , 15 Its superiority is thought to arise from the low phonon energy in fluoride lattice 16 as well as shorter R–R distance compared with the cubic structure of NaYF 4 :Yb 3+ ,Er 3+ .…”

Section: Introductionmentioning

confidence: 99%

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Effective Shielding of NaYF₄:Yb³⁺,Er³⁺ Upconverting Nanoparticles in Aqueous Environments Using Layer-by-Layer Assembly

et al. 2018

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Aqueous solutions are the basis for most biomedical assays, but they quench the upconversion luminescence significantly. Surface modifications of upconverting nanoparticles are vital for shielding the obtained luminescence. Modifications also provide new possibilities for further use by introducing attaching sites for biomolecule conjugation. We demonstrate the use of a layer-by-layer surface modification method combining varying lengths of negatively charged polyelectrolytes with positive neodymium ions in coating the upconverting NaYF4:Yb3+,Er3+ nanoparticles. We confirmed the formation of the bilayers and investigated the surface properties with Fourier transform infrared and reflectance spectroscopy, thermal analysis, and ζ-potential measurements. The effect of the coating on the upconversion luminescence properties was characterized, and the bilayers with the highest improvement in emission intensity were identified. In addition, studies for the nanoparticle and surface stability were carried out in aqueous environments. It was observed that the bilayers were able to shield the materials’ luminescence from quenching also in the presence of phosphate buffer that is currently considered the most disruptive environment for the nanoparticles.

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Section: Resultscontrasting

confidence: 56%

Section: Introductionmentioning

confidence: 99%

Effective Shielding of NaYF₄:Yb³⁺,Er³⁺ Upconverting Nanoparticles in Aqueous Environments Using Layer-by-Layer Assembly

et al. 2018

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“…However, it must be noted that for ionic Yb/Er systems the ETU rise time can extend up to the millisecond range as shown in e.g. [51][52][53]. Thus, we conclude that the mechanism may be either one of these or a mixture of them.…”

mentioning

confidence: 61%

Up-converting ALD/MLD thin films with Yb3+, Er3+ in amorphous organic framework

Tuomisto

Giedraityte

Mai

et al. 2019

Journal of Luminescence

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Near-infrared to green and red up-conversion is reported for a new type of hybrid (Yb,Er)-IR-806 films prepared using the atomic/molecular layer deposition (ALD/MLD) thin-film fabrication technology. These amorphous films can be realized in controllable nanothicknesses and they show an exceptionally wide absorption band in the near-infrared region. The films exhibit a highly local upconversion excitation process, which suggests strong potential for use as e.g. temperature sensors with Ångström scale surface resolution.

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“…Materials . NaYF 4 :Yb 3+ ,Er 3+ ( X Yb =0.17, X Er =0.03) and NaYF 4 :Yb 3+ , Tm 3+ ( X Yb =0.2, X Tm =0.005) UCNPs were synthesized in organic oils . Poly(acrylic acid) (PAA, M =2000 g mol −1 , Sigma–Aldrich) was used for UCNP coating.…”

Section: Methodsmentioning

confidence: 99%

“…NaYF 4 :Yb 3 + ,Er 3 + (X Yb = 0.17, X Er = 0.03) and NaYF 4 :Yb 3 + , Tm 3 + (X Yb = 0.2, X Tm = 0.005) UCNPs were synthesized in organic oils. [15] Poly(acrylic acid) (PAA, M = 2000 gmol À1 ,S igma-Aldrich) was used for UCNP coating. Monoclonal antibody (Mab) clones 5404 and 5409 specific for human TSH were purchased from Medix Biochemica (Espoo, Finland).…”

Section: Methodsmentioning

confidence: 99%

Upconversion Cross‐Correlation Spectroscopy of a Sandwich Immunoassay

Lahtinen

Krause

Arppe

et al. 2018

Chemistry A European J

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Fluorescence correlation and cross‐correlation spectroscopy (FCS/FCCS) have enabled biologists to study processes of transport, binding, and enzymatic reactions in living cells. However, applying FCS and FCCS to samples such as whole blood and plasma is complicated as the fluorescence bursts of diffusing labels can be swamped by strong autofluorescence. Here we present cross‐correlation spectroscopy based on two upconversion nanoparticles emitting at different wavelengths on the anti‐Stokes side of a single excitation laser. This upconversion cross‐correlation spectroscopy (UCCS) approach allows us to completely remove all Stokes shifted autofluorescence background in biological material such as plasma. As a proof of concept, we evaluate the applicability of UCCS to a homogeneous sandwich immunoassay for thyroid stimulating hormone measured in buffer solution and in plasma.

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Highly uniform up-converting nanoparticles: Why you should control your synthesis even more

Cited by 29 publications

References 39 publications

Effective Shielding of NaYF₄:Yb³⁺,Er³⁺ Upconverting Nanoparticles in Aqueous Environments Using Layer-by-Layer Assembly

Effective Shielding of NaYF₄:Yb³⁺,Er³⁺ Upconverting Nanoparticles in Aqueous Environments Using Layer-by-Layer Assembly

Up-converting ALD/MLD thin films with Yb3+, Er3+ in amorphous organic framework

Upconversion Cross‐Correlation Spectroscopy of a Sandwich Immunoassay

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Highly uniform up-converting nanoparticles: Why you should control your synthesis even more

Cited by 29 publications

References 39 publications

Effective Shielding of NaYF4:Yb3+,Er3+ Upconverting Nanoparticles in Aqueous Environments Using Layer-by-Layer Assembly

Effective Shielding of NaYF4:Yb3+,Er3+ Upconverting Nanoparticles in Aqueous Environments Using Layer-by-Layer Assembly

Up-converting ALD/MLD thin films with Yb3+, Er3+ in amorphous organic framework

Upconversion Cross‐Correlation Spectroscopy of a Sandwich Immunoassay

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Effective Shielding of NaYF₄:Yb³⁺,Er³⁺ Upconverting Nanoparticles in Aqueous Environments Using Layer-by-Layer Assembly

Effective Shielding of NaYF₄:Yb³⁺,Er³⁺ Upconverting Nanoparticles in Aqueous Environments Using Layer-by-Layer Assembly