scholarly journals Temperature Sensing in the Short-Wave Infrared Spectral Region Using Core-Shell NaGdF4:Yb3+, Ho3+, Er3+@NaYF4 Nanothermometers

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1992
Author(s):  
Daria Pominova ◽  
Vera Proydakova ◽  
Igor Romanishkin ◽  
Anastasia Ryabova ◽  
Sergei Kuznetsov ◽  
...  
Keyword(s):  
Rare Earth ◽  
Spectral Region ◽  
Thermal Sensitivity ◽  
Short Wave ◽  
Temperature Sensing ◽  
Rare Earth Ions ◽  
Core Shell ◽  
Dry Powder ◽  
Shell Nanoparticles ◽  
Short Wave Infrared

The short-wave infrared region (SWIR) is promising for deep-tissue visualization and temperature sensing due to higher penetration depth and reduced scattering of radiation. However, the strong quenching of luminescence in biological media and low thermal sensitivity of nanothermometers in this region are major drawbacks that limit their practical application. Nanoparticles doped with rare-earth ions are widely used as thermal sensors operating in the SWIR region through the luminescence intensity ratio (LIR) approach. In this study, the effect of the shell on the sensitivity of temperature determination using NaGdF4 nanoparticles doped with rare-earth ions (REI) Yb3+, Ho3+, and Er3+ coated with an inert NaYF4 shell was investigated. We found that coating the nanoparticles with a shell significantly increases the intensity of luminescence in the SWIR range, prevents water from quenching luminescence, and decreases the temperature of laser-induced heating. Thermometry in the SWIR spectral region was demonstrated using synthesized nanoparticles in dry powder and in water. The core-shell nanoparticles obtained had intense luminescence and made it possible to determine temperatures in the range of 20–40 °C. The relative thermal sensitivity of core-shell NPs was 0.68% °C−1 in water and 4.2% °C−1 in dry powder.

scholarly journals Real-Time Imaging of Short-Wave Infrared Luminescence Lifetimes for Anti-counterfeiting Applications

2021 ◽  
Vol 9 ◽  
Author(s):  
Roman Ziniuk ◽  
Artem Yakovliev ◽  
Hui Li ◽  
Guanying Chen ◽  
Junle Qu ◽  
...  
Keyword(s):  
Rare Earth ◽  
Real Time ◽  
Frequency Conversion ◽  
Imaging System ◽  
Short Wave ◽  
Rare Earth Ions ◽  
High Rate ◽  
Luminescence Spectra ◽  
Real Time Imaging ◽  
Short Wave Infrared

Rare-earth doped nanoparticles (RENPs) have been widely used for anti-counterfeiting and security applications due to their light frequency conversion features: they are excited at one wavelength, and they display spectrally narrow and distinguished luminescence peaks either at shorter wavelengths (i.e., frequency/energy upconversion) or at longer wavelengths (frequency/energy downconversion). RENPs with a downconversion (DC) photoluminescence (PL) in short-wave infrared (SWIR) spectral range (~1,000–1,700 nm) have recently been introduced to anti-counterfeiting applications, allowing for multilevel protection based on PL imaging through opaque layers, due to a lesser scattering of SWIR PL emission. However, as the number and spectral positions of the discrete PL bands exhibited by rare-earth ions are well-known, it is feasible to replicate luminescence spectra from RENPs, which results in a limited anti-counterfeiting security. Alternatively, lifetime of PL from RENPs can be used for encoding, as it can be finely tuned in broad temporal range (i.e., from microseconds to milliseconds) by varying type of dopants and their content in RENPs, along with the nanoparticle morphology and size. Nevertheless, the current approach to decoding and imaging the RENP luminescence lifetimes requires multiple steps and is highly time-consuming, precluding practical applications of PL lifetime encoding for anti-counterfeiting. Herein, we report the use of a rapid lifetime determination (RLD) technique to overcome this issue and introduce real-time imaging of SWIR PL lifetime for anti-counterfeiting applications. NaYF4:20% Yb, x% Er (x = 0, 2, 20, 80)@NaYF4 core@shell RENPs were synthesized and characterized, revealing DC PL in SWIR region, with maximum at ~1,530 nm and PL lifetimes ranging from 3.2 to 6 ms. Imaging of the nanoparticles with different lifetimes was performed by the developed time-gated imaging system engaging RLD method and the precise manipulation of the delay between the excitation pulses and camera gating windows. Moreover, it is shown that imaging and decrypting can be performed at a high rate (3–4 fps) in a cyclic manner, thus allowing for real-time temporal decoding. We believe that the demonstrated RLD-based fast PL lifetime imaging approach can be employed in other applications of photoluminescent RENPs.

Optical Temperature Sensing of Core-Shell Structured NaYF4:Yb3+, Er3+@NaYF4 Nanocrystals with Different Shell Thickness

2015 ◽  
Vol 738-739 ◽  
pp. 27-30
Author(s):  
Dong Dong Li ◽  
Qi Yue Shao ◽  
Yan Dong ◽  
Jian Qing Jiang
Keyword(s):  
Shell Thickness ◽  
Thermal Sensitivity ◽  
Upconversion Luminescence ◽  
Temperature Sensing ◽  
Upconversion Nanoparticles ◽  
Core Shell ◽  
Sensing Properties ◽  
The Core ◽  
Β Phase ◽  
Biomedical Fields

Hexagonal (β)-phase NaYF4:Yb3+, Er3+ upconversion nanoparticles (UCNPs) with and without an inert (undoped NaYF4) shell have been successfully synthesized and the effects of shell thickness on the upconversion luminescence (UCL) and temperature sensing properties were systematically investigated. It was found that the NaYF4 shell and its thickness do not affect the RHS values and thermal sensitivity, but can obviously improve the UCL intensity of NaYF4:Yb3+, Er3+ UCNPs. It implies that the core-shell structured NaYF4:Yb3+, Er3+@NaYF4 UCNPs with excellent UCL properties have great potential to be used as temperature sensing probes in biomedical fields, without considering the influences of the shell thickness on their temperature sensing properties.

scholarly journals Strongly Exchange Coupled Core|Shell Nanoparticles with High Magnetic Anisotropy: A Strategy toward Rare-Earth-Free Permanent Magnets

2016 ◽  
Vol 28 (12) ◽  
pp. 4214-4222 ◽  
Author(s):  
E. Lottini ◽  
A. López-Ortega ◽  
G. Bertoni ◽  
S. Turner ◽  
M. Meledina ◽  
...  
Keyword(s):  
Rare Earth ◽  
Magnetic Anisotropy ◽  
Permanent Magnets ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

scholarly journals Rare-Earth-Doped Nanoparticles for Short-Wave Infrared Fluorescence Bioimaging and Molecular Targeting of αVβ3-Expressing Tumors

2018 ◽  
Vol 17 ◽  
pp. 153601211879913 ◽  
Author(s):  
Dominik Jan Naczynski ◽  
Jason H. Stafford ◽  
Silvan Türkcan ◽  
Cesare Jenkins ◽  
Ai Leen Koh ◽  
...  
Keyword(s):  
Rare Earth ◽  
Lymphatic Mapping ◽  
Tumor Model ◽  
Short Wave ◽  
Molecular Targeting ◽  
Photon Scattering ◽  
Tissue Penetration ◽  
Fluorescence Bioimaging ◽  
Short Wave Infrared ◽  
Rare Earth Doped

The use of short-wave infrared (SWIR) light for fluorescence bioimaging offers the advantage of reduced photon scattering and improved tissue penetration compared to traditional shorter wavelength imaging approaches. While several nanomaterials have been shown capable of generating SWIR emissions, rare-earth-doped nanoparticles (REs) have emerged as an exceptionally bright and biocompatible class of SWIR emitters. Here, we demonstrate SWIR imaging of REs for several applications, including lymphatic mapping, real-time monitoring of probe biodistribution, and molecular targeting of the αvβ3 integrin in a tumor model. We further quantified the resolution and depth penetration limits of SWIR light emitted by REs in a customized imaging unit engineered for SWIR imaging of live small animals. Our results indicate that SWIR light has broad utility for preclinical biomedical imaging and demonstrates the potential for molecular imaging using targeted REs.

Optical temperature sensing of rare-earth ion doped phosphors

RSC Advances ◽  
2015 ◽  
Vol 5 (105) ◽  
pp. 86219-86236 ◽  
Author(s):  
Xiangfu Wang ◽  
Qing Liu ◽  
Yanyan Bu ◽  
Chun-Sheng Liu ◽  
Tao Liu ◽  
...  
Keyword(s):  
Rare Earth ◽  
Temperature Measurement ◽  
Large Scale ◽  
Temperature Sensing ◽  
Rare Earth Ions ◽  
Promising Method ◽  
Current Status ◽  
Rare Earth Ion ◽  
Optical Thermometry

Optical temperature sensing is a promising method to achieve the contactless temperature measurement and large-scale imaging. The current status of optical thermometry of rare-earth ions doped phosphors is reviewed in detail.

Facile synthesis of flower-shaped Au/GdVO4:Eu core/shell nanoparticles by using citrate as stabilizer and complexing agent

RSC Advances ◽  
2016 ◽  
Vol 6 (12) ◽  
pp. 9612-9618 ◽  
Author(s):  
Ming Chen ◽  
Jia-Hong Wang ◽  
Zhi-Jun Luo ◽  
Zi-Qiang Cheng ◽  
Ya-Fang Zhang ◽  
...  
Keyword(s):  
Rare Earth ◽  
Complexing Agent ◽  
Core Shell ◽  
Facile Synthesis ◽  
Shell Nanoparticles ◽  
Rare Earth Compound ◽  
Earth Core ◽  
Core Shell Nanoparticles

The synthesis of metal/rare-earth core/shell hetero-nanostructures through directly coating rare-earth compound onto the surface of Au nanocrystals.

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