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Ultrasharp LSPR Temperature Sensor Based on Grapefruit Fiber Filled with a Silver Nanoshell and Liquid
摘要： A grapefruit fiber (GF) based temperature sensor with ultrasharp localized surface plasmon resonance (LSPR) is designed and characterized by finite element method. The silver nanoshell (SNS), formed by a dielectric core and a silver shell together with chloroform own large thermo-optic coefficient is sealed into one large air hole of the GF as the core sensing region. Benefiting from the plasmon hybridization in SNS and birefringence, the designed sensor can support two separate ultrasharp resonance peaks with full width half maximum (FWHM) only 4.6 nm in orthogonal polarizations, which is the narrowest to our best knowledge and the highest figure of merit (FOM) of 0.43/℃ can be obtained. Results show that by following the shifts of two polarized peaks, dual channel temperature sensing can be realized simultaneously at 5℃-55℃ with the maximum sensitivity of -17.8 nm/℃ and -17.2 nm/℃, about 3-17 times higher than other same type works. Moreover, the influences of structure parameters of SNS like deposition position, number, diameter and length on the sensing performances are discussed in detail.
关键词： silver nanoshell,ultrasharp localized surface plasmon resonance,Grapefruit fiber,dual channel temperature sensing
更新于2025-09-11 14:15:04
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Optical temperature sensing of Eu3+-doped oxyhalide glasses containing CsPbBr3 perovskite quantum dots
摘要： A new strategy for optical thermometer with high sensitivity was developed herein by employing exciton recombination of CsPbBr3 quantum dots as temperature detecting signal and 4f→4f transition Eu3t ions as reference one. A series of structural and spectroscopic characterizations confirmed that CsPbBr3 perovskite quantum dots were successfully precipitated and Eu3t doping activators remained in glass matrix. Benefited from their completely different thermal-quenching behaviors, fluorescence intensity ratio of exciton recombination and Eu3t emission in nanocomposite exhibited excellent temperature sensing property in the temperature ranging from 93 K to 383 K. The maximum absolute and relative temperature sensitivity can reach as high as 0.0224 K-1 and 2.25% K-1, respectively. We believe that this work will exploit an effective pathway for developing innovative non-contact optical thermometric materials.
关键词： Glass,Perovskite quantum dots,Eu3t,Temperature sensing,CsPbBr3
更新于2025-09-11 14:15:04
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Surface state-controlled C-dot/C-dot based dual-emission fluorescent nanothermometers for intra-cellular thermometry
摘要： Fluorescence-based nanothermometers have potential to offer accuracy in the measurement of temperature using non-contact approaches. Herein, a C-dot/C-dot based dual-emission temperature sensing platform is fabricated through the electrostatic self-assembly of two kinds of fluorescent CDs with opposite charges. This dual-emission platform consists of several nearly-spherical CDs with two emission centers in blue (440 nm) and orange (590 nm) regions. The orange fluorescence exhibits discernible response to external temperatures in the range of ～15 to 85 °C; on the other hand, the blue fluorescence remains nearly constant. A continuous fluorescence color change in response to temperature from orange to blue can be clearly observed by the naked eye. Thus, the as-prepared C-dot based dual-emission nanospheres can be used for optical thermometry with high reproducibility and sensitivity (0.93%/°C). Detailed characterization shows that temperature (in the 15–85 °C window) impacts the surface states of orange emissive CDs, leaving the blue emissive CDs unaffected. A model is proposed to explain the observations. Finally, by taking advantage of the excellent biocompatibility and stability, the CD based fluorescent nanothermometer is successfully used for the visual measurement of intracellular temperature variations.
关键词： intracellular thermometry,temperature sensing,nanothermometers,dual-emission,fluorescence,carbon dots
更新于2025-09-11 14:15:04
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UV-light-activated H2S gas sensing by a TiO2 nanoparticulate thin film at room temperature
摘要： A UV-light-activated TiO2 thin film gas sensor composed of nanoparticles is reported for H2S detection at room temperature. TiO2 nanoparticulate thin films were fabricated by bar coating of a mixture of TiO2 powder and acetic acid. The morphology and structural properties of the films were examined by scanning electron microscopy, X-ray diffraction, photoluminescence spectroscopy, and absorption spectroscopy. The nil response to H2S was significantly enhanced by UV light irradiation in the response levels and response/recovery kinetics. The effect of the sensor conductance and light intensity towards sensor optimization was discussed. The sensor exhibited high gas selectivity, repeatability, and linearity for practical applications of the sensor, but the interference of humidity on the sensing process needs to be solved. The results exhibited a simple way to detect parts per million concentrations of H2S at room temperature.
关键词： TiO2 nanoparticulate thin film,room temperature sensing,UV-light-activated sensing,H2S
更新于2025-09-10 09:29:36
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Modeling of Quench Behavior of YBa<formula><tex>$_{2}$</tex></formula>Cu<formula><tex>$_{3}$</tex></formula>O<formula><tex>$_{7-\delta}$</tex></formula> Pancake Magnets and Distributed Temperature Sensing-based Quench Detection for Operating Temperature 30 K - 77 K
摘要： A two-dimensional/three-dimensional (2-D/3-D) mixed electrothermal model is proposed for the simulation of quench behavior of high-temperature superconducting (HTS) pancake magnets, where a 2-D electrothermal model is proposed to simulate the YBa2 Cu3 O7 -δ (YBCO) subcoil and is coupled with the remaining parts of the YBCO magnet, which are treated as 3-D homogeneous coils. For operating temperature from 30 to 77 K, the quench behavior of four YBCO pancake coils (two Kapton-insulated coils and two TiO2 -insulated coils) are simulated. Thermal equilibrium states are found for both Kapton- and TiO2 -insulated coils. The thermal conductivity of insulating materials (Kapton, TiO2 ) significantly affects the equilibrium temperature profiles (ETPs) and the minimum quench energy (MQE), especially for relatively high operating temperature (e.g., 65–77 K). The distributed-temperature-sensing-based (DTS-based) quench detection criterion can be established on ETPs. The effect of the thickness of insulating materials on ETPs and MQEs is relatively weak, especially under relatively low operating temperature. The key parameters of ETP-based quench detection criterion, such as the reference temperature, the peak temperature, and the minimum normal zone size, are obtained for the operating temperature from 30 to 77 K.
关键词： quench detection criterion,Distributed temperature sensing (DTS),high-temperature superconducting (HTS) magnet,quench simulation,minimum quench energy (MQE)
更新于2025-09-10 09:29:36
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Effect of Li co-doping with Er on up-conversion luminescence property and its temperature dependence of NaY(WO4)2
摘要： NaY(WO4)2 phosphors with different Er3+ doping and Er3+/Li+ co-doping concentrations were prepared via high temperature solid state reaction. X-ray diffraction measurement demonstrated the presence of tetragonal-phase NaY(WO4)2, and no impurity phase was found in Er3+/Li+ co-doped samples. Well-crystallized NaY(WO4)2 phosphors showed a fine morphology with particle sizes of 1–6 μm determined by scanning electron microscope. Under excitation at 980 nm, the origins of three emission peaks located at 527 nm (green emission 1), 549 nm (green emission 2) and 665 nm (red emission), respectively, were identified. By introducing Li+, the up-converted (UC) emission intensity was enhanced by 0.5 times and 2 times in green and red emission region, respectively. The enhanced luminescence was attributed to the distortion of the local symmetry around Er3+ due to Li+ incorporation in the lattices. The 2H11/2 → 4I15/2 (green emission 1) and 4S3/2 → 4I15/2 (green emission 2) transitions of the Er3+ ion presented a temperature dependent behavior from 300 to 30 K and were proposed for temperature sensing (optical thermometry) by using the fluorescence intensity ratio (FIR) method. The FIR data obtained by experiment was well fitted with a theoretical function. A higher maximum value of sensitivity (0.0061 K-1) was obtained in 5% Er3+, 0% Li+ doped sample at 300 K. However, due to the distortion of local crystal field around Er3+ ions caused by the introduction of Li+, the sensitivity value of 5% Er3+ and 1% Li+ co-doped sample was higher than that of Li+ free sample below 270 K, which indicated that appropriate Li+ co-doping could optimize the temperature sensing behaviors of Er3+ doped NaY(WO4)2 phosphors.
关键词： Upconversion photoluminescence,Li+ co-doping,Alkaline earth oxides,Temperature sensing
更新于2025-09-10 09:29:36
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Yb3+/Tb3+/Ho3+: phosphate nanophase embedded glass ceramics: enhanced upconversion emission and temperature sensing behavior
摘要： Yb3+/Tb3+/Ho3+ tri-doped transparent phosphate glass–ceramics (GCs) were successfully synthetized by a conventional melt-quenching technique with subsequent glass crystallization. The formation of phosphate nanocrystals (NCs) with leucite structure was confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), selected-area electron diffraction (SAED). The variation of the decay curves confirms the accumulation of active centers into the NCs lattice. Hence, the UC emission intensity of Yb3+/Tb3+/Ho3+ doped GC610 sample is greatly enhanced relative to that in precursor glass (PG). And the UC energy transfers processes were systematically analysis. The result shows that the energy transfer of Ho3+→Tb3+ exists while Yb3+ as a sensitizer ion. Furthermore, the temperature-dependent UC luminescence and temperature sensing behaviors of the prepared materials based on the thermally coupled levels of Tb3+: 5D4 and Ho3+: 5F5 in the temperature range of 298–648 K were systematically investigated, to explore its possible application as optical thermometric medium, by utilizing the fluorescence intensity ratio (FIR) technique. The relative sensitivity (Sr) of 7.5 × 10?3 K?1 and absolute sensitivity (Sa) of 22 × 10?3 K?1 are achieved in the Yb3+/Tb3+/Ho3+ tri-doped GC. This GC materials is a very promising candidate for optical temperature sensors.
关键词： Yb3+/Tb3+/Ho3+ tri-doped,phosphate glass–ceramics,upconversion emission,temperature sensing,optical thermometry
更新于2025-09-10 09:29:36
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Improvement in upconversion/downshifting luminescence of Gd2O3 :Ho3+/Yb3+ phosphor through Ca2+ / Zn2+ incorporation and optical thermometry studies
摘要： The Ho3+/Yb3+ doped Gd2O3 phosphor was synthesized via the hydrothermal process. Co-doping of Ca2+ and Zn2+ ions caused a change in the particle morphology and aggregation of the Ho3+/Yb3+: Gd2O3 phosphor. The structural characterization of these particles was performed using X-ray diffraction analysis, Fourier transforms infrared spectroscopy and scanning electron microscopy. The 980 nm excitation assisted upconversion luminescence and 449 nm excitation assisted downshifting luminescence of these phosphor particles were compared through the incorporation of Ca2+ and Zn2+ co-dopants. The co-dopants concentration was varied at 0, 5, 10, 15 and 20 mol %. The change in upconversion/downshifting luminescence under the influence of the optimized molar concentration of these co-dopants was studied and explained based on structural variations in the present phosphor material. The paramagnetic behavior of these particles was characterized and compared to search possible applications of these particles in the biomedical field. The samples were studied comparatively for temperature sensing.
关键词： Temperature sensing,Upconversion/Downshifting,Ca2+/Zn2+,M-H plot,Ho3+/Yb3+: Gd2O3
更新于2025-09-10 09:29:36
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Temperature Sensing of Deep Abdominal Region in Mice by Using Over-1000 nm Near-Infrared Luminescence of Rare-Earth-Doped NaYF4 Nanothermometer
摘要： Luminescence nanothermometry has attracted much attention as a non-contact thermal sensing technique. However, it is not widely explored for in vivo applications owing to the low transparency of tissues for the light to be used. In this study, we performed biological temperature sensing in deep tissues using β-NaYF4 nanoparticles co-doped with Yb3+, Ho3+, and Er3+ (NaYF4: Yb3+, Ho3+, Er3+ NPs), which displayed two emission peaks at 1150 nm (Ho3+) and 1550 nm (Er3+) in the >1000 nm near-infrared wavelength region, where the scattering and absorption of light by biological tissues are at the minimum. The change in the luminescence intensity ratio of the emission peaks of Ho3+ and Er3+ (IHo/IEr) in the NaYF4: Yb3+, Ho3+, Er3+ nanothermometer differs corresponding to the thickness of the tissue. Therefore, the relationship between IHo/IEr ratio and temperature needs to be calibrated by the depth of the nanothermometer. The temperature-dependent change in the IHo/IEr was evident at the peritoneal cavity level, which is deeper than the subcutaneous tissue level. The designed experimental system for temperature imaging will open the window to novel luminescent nanothermometers for in vivo deep tissue temperature sensing.
关键词： near-infrared,Luminescence nanothermometry,biological window,NaYF4 nanoparticles,deep tissue temperature sensing
更新于2025-09-10 09:29:36
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Simultaneously tuning emission color and realizing optical thermometry via efficient Tb3+→Eu3+ energy transfer in whitlockite-type phosphate multifunctional phosphors
摘要： A series of Ca8ZnLa(PO4)7 (CZLPO) phosphors doped with Tb3+ and Eu3+ have been synthesized using a high-temperature solid-state method. The XRD pattern verifies that all prepared samples are attributed to whitlockite-type structure of β-Ca3(PO4)2 with R3c (161) space group. Under 366 nm excitation, the CZLPO: Tb3+, Eu3+ phosphors exhibit a tunable multi-color emission owing to energy transfer from Tb3+ to Eu3+ via a quadrupole-quadrupole interaction mechanism. The emission colors of the phosphors could be modulated from green to red under NUV (366 nm) excitation due to efficient Tb3+/Eu3+ energy transfer. The fluorescence intensity ratio (I542nm/I611nm) for the Tb3+/Eu3+ of this material displayed excellent temperature sensing properties between 298 and 498 K. Moreover, it was found that the intensity ratio was unchanged when the temperature was cycled between 298 and 498 K, thus demonstrating the recyclability of this system. These results show that CZLPO: Tb3+, Eu3+ phosphors have potential as high performance multifunctional materials for solid state lighting and temperature sensing applications.
关键词： Ca8ZnLa(PO4)7: Tb3+,Energy transfer,Eu3+,Color tuning,Temperature sensing
更新于2025-09-10 09:29:36