Materials Research Express
·
2019
·Vol. 6
·期 12
·125017
·
IF 1.449
Hanyu Yao,Honglie Shen,Quntao Tang
In this paper, Mn doped NaYF4:Er,Yb phosphors were successfully synthesized by a simple solvothermal method. According to the results of x-ray diffraction, scanning electron microscopy and photoluminescence measurement, Mn doping had a remarkable effect on the crystal phase, size, and especially upconversion (UC) properties of these phosphors. Under 980 nanometer (nm) laser excitation, the UC luminescence intensity could be enhanced by increasing Mn concentration. Temperature-dependence measurement of the samples from 300–30 K showed two green emission bands (2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions of the Er3+ ion), which meant that the UC phosphors were suitable for temperature sensor by using the fluorescence intensity ratio (FIR) method. The FIR value decreased with temperature, and the experimental data were well fitted with a theoretical function. The higher maximum value of sensitivity (0.0057 K−1) for 20% Mn sample in contrast to that of 0% Mn one (0.0036 K−1) indicated that Mn doped sample had a higher sensitivity for temperature sensing. The results demonstrated that Mn doping would be a good way for optimizing the sensitivity of fluorescence-based temperature sensor.
研究领域:
材料科学
·
光学
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DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2014
·Vol. 16
·期 37
·20009-20012
·
IF 4.198
Bin Dong,Rui N. Hua,Bao S. Cao,Zhi P. Li,Yang Y. He,Zhen Y. Zhang,Otto S. Wolfbeis
The size-dependent temperature sensitivity is observed on the upconversion luminescence of NaYF4:Er,Yb microspheres with sizes between 0.7 and 2 μm that are prepared by a poly(acrylic acid)-assisted hydrothermal process. It is found that the fluorescence intensity ratio (FIR) of their green upconversion emissions (with peaks at 521 and 539 nm) is strongly size-dependent at temperatures between 223 and 403 K. As the size of the spheres increases from 0.7 to 1.6 μm, the maximum sensitivity decreases from 36.8 × 10−4 to 24.7 × 10−4 K−1. This effect is mainly attributed to the larger specific surface area of the smaller spheres where a relatively large number of Er(III) ions are located at the surface. This results in an increase in the efficiency of the 4S3/2 → 2H11/2 population process of the Er(III) ions due to stronger electron–phonon interactions with increasing T. Heating of the spheres by NIR light is also supposed to cause enhanced electron–phonon interactions in such particles.
研究领域:
材料科学
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光学
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纳米技术
✓ 已验证
DOI
高影响因子
MICROCHIMICA ACTA
·
2017
·Vol. 184
·期 9
·3469-3475
·
IF 4.58
Tang Yiwei,Li Min,Gao Xue,Liu Xiuying,Gao Jinwen,Ma Tao,Li Jianrong
The paper describes the preparation of a fluorescent probe based on the use of up-conversion particles (UCPs) of the type NaYF 4 : Er, Yb and shelled with a molecularly imprinted polymer (MIP) that is specific for the antibiotic enrofloxacin. The upconverted green luminescence emitted by the UCPs upon photoexcitation at 980 nm was used to locally generate a thin MIP shell around the UCPs via photopolymerization. Enrofloxacin is used as the template, and ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent. It is found that enrofloxacin is well captured by the MIP and then quenches the fluorescence of the UCPs. Fluorescence decreases linearly in the 63 ng·L −1 to 60 μg·L −1 enrofloxacin concentration range, with a 8 ng·L −1 limit of detection. The method was applied to the determination of enrofloxacin in spiked fish samples. Recoveries ranged from 83.7 to 87.7%, with relative standard deviations between 2.0 and 5.5% (for n = 3).
Schematic of an NIR-responsive up-conversion nanoparticle probe of the NaYF 4 :Er,Yb type and coated with a MIP for fluorometric determination of enrofloxacin. The upconverted luminescence emitted by the UCPs was used to locally generate a thin MIP shell around the UCPs via photopolymerization.
研究领域:
分析化学
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纳米技术
·
药物分析
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DOI
高影响因子
INORGANIC CHEMISTRY
·
2021
·
IF 5.165
Jingbo Yu,Lili Hu,Yujing Shen,Jinjun Ren
A series of glasses with composition 60NaPO3–(40-x)CdF2–xYF3–yEr2O3 were synthesized via melt-quenching methods and subsequently heat-treated to obtain upconversion luminescent glass ceramics containing NaYF4:Er crystals. Hexagonal and/or cubic NaYF4 crystals were controlled to be bred in the glasses by changing the glass composition. The structure evolution driven by crystallization was characterized using advanced solid-state nuclear magnetic resonance (SSNMR) techniques. The SSNMR results reveal that the Y/Na ratio determines the crystalline phases of NaYF4 precipitated in this glass system. Y3+ attracts extra F– ions from P5+ and Cd2+ during crystallization because of its stronger ability to attract F– ions, leading to most Y3+ ions being crystallized into the NaYF4 crystals. The paramagnetic broadening effect of the Er3+ ions on NMR signals as well as the upconversion luminescence results indicate that, before crystallization, most Er3+ ions are surrounded by oxygen within the glasses; however, after crystallization, almost all of them enter the NaYF4 crystals. On the basis of this local structure investigation, a composition design strategy is developed to obtain highly efficient upconversion luminescent glass ceramics.
研究领域:
材料科学
·
光物理学
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2017
·Vol. 5
·期 26
·6512-6520
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IF 5.256
Mengxiao Li,Weijing Yao,Jun Liu,Qingyong Tian,Li Liu,Jin Ding,Qingwen Xue,Qiang Lu,Wei Wu
Rare-earth ion (RE3+) doped up-conversion (UC) fluorescent materials and novel fluorescent carbon quantum dots (CDs) have been widely used as traditional anti-counterfeiting materials owing to their excellent optical properties. The drawbacks of these materials are being exposed gradually with the widespread occurrence of counterfeit products in the market because of their single fluorescence mode and easy replication. In this work, we propose a novel strategy to combine both luminescent materials with different modes via a facile solvothermal method. Interesting, the composite materials show unalterable down-conversion (DC) blue light under a 365 nm ultraviolet (UV) analyzer, except for adjustable UC luminescence properties. The UC and DC optical properties are measured and the probable mechanism is proposed, indicating that the dual-mode fluorescence processes are separate and do not interference with each other. Moreover, we use a mixture containing a small number of UCMPs/CDs and poly(acrylic acid) (PAA) aqueous solution as a colorless anti-counterfeiting ink, and successfully print a variety of dual-mode fluorescence patterns through the screen printing technique, including QR codes, the logo of Wuhan University, and clover patterns. The composite materials show good dispersion and outstanding dual-mode fluorescence properties, suggesting that they are promising luminescent materials in the anti-counterfeiting field.
研究领域:
材料科学
·
光学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Healthcare Materials
·
2022
·Vol. 12
·期 2
·2202117
·
IF 11.092
Shanshan Peng,Lizhen Wang,Lin Liu,Liang Song,Junpeng Shi,Hanrun Zheng,Jixuan Xu,Rui Rong,Yun Zhang
Manipulation of autophagic processes has emerged as a promising strategy for synergizing nanoagent-mediated photothermal therapy (PTT). Most of the current studies focus on improving PTT efficacy by inhibiting pro-survival autophagy induced by the heat generated from the photothermal process. However, autophagy induced by the nanoagents is usually ignored, which may weaken the effect of autophagy-mediated efficacy improvement in PTT if induced autophagy is pro-death. Therefore, this work aims at developing a nanoagent that is able to induce heat-synergetic pro-survival autophagy to optimize the efficacy of PTT. An approach is developed to coat carbon layer, polyethylenimine (PEI), and folic acid (FA) on NaYF 4 :Er,Yb,Nd@NaNdF 4 (DCNPs@C@PEI@FA, DCPF) nanoparticles successively, giving access to the nanoagent to induce pro-survival autophagy. The synthetic imaging-guided photothermal nanoagent displays outstanding targeting ability and biocompatibility based on the surface modification of PEI and FA. By using an autophagy inhibitor chloroquine, a conspicuously synergistic effect on DCPF-mediated PTT in vitro and in vivo tumor models (HeLa) is achieved. A promising strategy is presented here to enhance the efficacy of imaging-guided PTT by modulating the autophagy induced by the nanoagent.
研究领域:
纳米技术
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癌症治疗
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材料科学
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生物医学工程
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Shuguang Li,Jize Liu,Haibo Wu,Xinxin Zhang,Yanqiong Guo,Boyang Kang,Limin Zhao
Photocatalytic hydrogen production with simultaneous degradation of organic pollutants by using solar energy provide a promising strategy to solve the energy and environmental issue in the future. However, for onefold wide band-gap semiconductor, the poor photocatalytic efficiency limits its application on a large scale due to its easy recombination of photo-generated electron-hole pairs and low solar energy utilization. Herein, a novel Z-scheme BiVO 4 (040)-Bi-(NaYF 4 :Er,Yb,Tm@BiOBr)/Bi photocatalyst is prepared via photo-assisted isoelectric point method. In this composite photocatalyst, up-convention luminescence material, NaYF 4 :Er,Yb,Tm, can offer more ultraviolet light and visible light to intensify the activations of BiOBr and metal Bi nanoparticles, respectively. Furthermore, the formation of Z-scheme BiVO 4 (040)-BiOBr photocatalystic sytem, the spatial separation of the BiVO 4 (040) and BiVO 4 (110) facets and the presence of metal Bi surface plasmon resonance effect are contributed to the high-efficiency separation of the photo-generated electron-hole pairs. The experimental results show that as-prepared Z-scheme BiVO 4 (040)-Bi-(NaYF 4 :Er,Yb,Tm@BiOBr)/Bi photocatalyst exhibits advanced photocatalytic hydrogen production amount (192.0 μm) and excellent degradation ratio of malachite green (88.51 %) under simulated sunlight irradiation for 5.0 h. The apparent quantum yield of the Z-scheme BiVO 4 (040)-Bi-(NaYF 4 :Er,Yb,Tm@BiOBr)/Bi photocatalyst at 420 nm reaches a specific value of 5.8 %. In addition, Z-scheme BiVO 4 (040)-Bi-(NaYF 4 :Er,Yb,Tm@BiOBr)/Bi photocatalyst also remains a high stability in the photocatalytic hydrogen production with simultaneous degradation of malachite green within six reuse. At last, the possible reaction mechanism and degradation pathways of malachite green caused by Z-scheme BiVO 4 (040)-Bi-(NaYF 4 :Er,Yb,Tm@BiOBr)/Bi photocatalyst under simulated sunlight irradiation are put forward.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）