CRYSTENGCOMM
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2024
·Vol. 26
·期 27
·3603-3608
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IF 2.6
Wenfei Xun,Zhipeng Meng,Chuwei Xie,Suli Wu
808 nm excited Nd3+ doped upconversion nanoparticles (UCNPs) have become a new research hotspot due to their reduced thermal effect when applied in a water-rich system. Different from Tm3+-mediated energy migration upconversion of Tb3+, in this work, NaYF4:Yb/Tb@NaYF4:Yb@NaNdF4:Yb@NaYF4 core–shell–shell–shell nanoparticles were designed based on the Yb3+ sensitized cooperative energy-transfer process to realize photon upconversion. NaYF4:Yb served as the migration layer, separating the activator Tb3+ from the sensitizer Nd3+ and minimizing the deleterious cross-relaxation between them. At 40% Yb3+ doping concentration in the NaYF4:Yb layer, bright green luminescence was achieved under 808 nm excitation. Meanwhile, the presence of Yb3+ in the sensitization layer (NaNdF4:Yb) reduced Nd3+ cross-relaxation, leading to improved energy migration efficiency of Nd3+ → Yb3+. Finally, the incorporation of an inert NaYF4 shell resulted in a significant luminescence boost. These nanoparticles can be dispersed in water after surface modification and could be effectively excited after laser penetration of 3 cm of water, indicating the enormous potential of the designed UCNPs in the biological system.
研究领域:
材料科学
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生物医学工程
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产品关联
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2025
·
IF 5.4
Zuodong Liu,Tingting Xiong,Chengwei Zhang,Qiyue Pan,Guo Zhang,Rui Liu,Yongsheng Yu,Peng Liu,Qiangshan Jing
A series of SrF 2 phosphors co-doped with Er 3+ and Y 3+ possessing regular polygon shapes were fabricated after calcination as-synthesized particles at 600 °C for 2 h. the crystal structure and morphology of the Er, Y:SrF 2 phosphors were identified. By incorporating the non-active Y 3+ ions as buffers into Er:SrF 2 phosphors, intense green up-conversion luminescence with modulating emission colors from reddish-yellow towards the greenish area is achieved. The two-photon up-conversion mechanism was also identified by the quadratic dependence between the luminescence intensities and 808 nm excitation source powers. The up-conversion luminescence characteristics indicate that Y 3+ buffers significantly enhance the 2 H 11/2 / 4 S 3/2 → 4 I 15/2 transitions, leading to an approximately five-fold increase in the luminescence intensities ratio R(g/r) of the green to red emissions in Er:SrF 2 phosphors.
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DOI
高影响因子
Journal of Physical Chemistry C
·
2018
·
IF 4.484
Tao Wang,Haifeng Zhou,Zhichao Yu,Guangjun Zhou,Juan Zhou,Dapeng Huang,Leilei Sun,Peng Gao,Yuzhen Sun,Jifan Hu
NaGdF4: A (A = Eu, Tb)@NaGdF4: Yb, Tm@NaGdF4: Yb, Nd core–shell–shell is designed to achieve 808 nm excited upconversion emission tuning. On the basis of the above core–shell–shell nanostructure, intense upconversion emission has been realized for activators without long-lived intermediate states (Eu3+, Tb3+) through Gd3+-mediated energy migration under 808 nm irradiation, enriching the emission colors. The spatial separation, where sensitizer (Nd3+), accumulator (Tm3+), and activator (Eu3+, Tb3+) are doped into separated layers, effectively suppresses nonradiative decays so that the doping concentration of Nd3+ can reach to 40%, vastly enhancing the luminescence intensity. Notably, when Gd3+ ions are replaced by Nd3+ or inert Y3+ in NaGdF4: Yb, Nd outer shell, without Gd3+-mediated energy migration, the deleterious energy transfer from Tm3+ in the interlayer to surface quenchers is suppressed, and thus, more active energy is trapped by activators, which induces the further change of upconversion emission color. Furthermore, the multicolor upconversion tuning can also be realized via Tb3+-mediated energy migration. 808 nm excited multicolor upconversion tuning, overcoming low tissue penetration and overheating effect under 980 nm excitation, improves the feasibility of upconversion nanoparticles in multicolor imaging and multiplexed detection areas.
研究领域:
材料科学
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光学
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生物医学工程
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 48
·17451-17460
·
IF 7.393
Tao Wang,Fenglei Sun,Zike Jiang,Jing Wang,Yanyan Ma,Haitao Lin,Hongmin Lv,Shanshan Xu,Jinhua Li,Guangjun Zhou
pH sensors based on up-conversion nanoparticles (UCNPs) are widely studied due to their effective elimination of background signals. However, ratiometric pH measurement depending on blue and red luminescence under NIR irradiation has been seldom reported for the lack of simultaneous strong blue and red emissions for traditional UCNPs. In this work, we designed NaGdF4:Yb,Tm@NaYF4:Yb,Eu@NaYF4:Yb,Nd@NaYF4 core–triple shell (CTS) UCNPs as fluorescent materials to realize blue/red ratiometric pH measurement. On the basis of Gd3+-mediated interfacial energy transfer and Yb3+-mediated energy migration, CTS particles present intense luminescence and a high red/blue (615 nm/450 nm) peak intensity ratio of 0.47 at 808 nm excitation. Composed of these particles and pH indicator bromocresol green, the pH sensor exhibits ratiometric responses in a pH range of 4–7 according to blue/red luminescence intensity ratios, avoiding the common errors as well as potential mutual fluorescence signal interference. Owing to strong overall luminescence and additional red emission of CTS UCNPs distinctly improving the signal-to-noise ratio, this ratiometric sensor reveals high sensitivity. Moreover, the employed excitation wavelength of 808 nm can not only eliminate autofluorescence signals, but also alleviate severe temperature rise in biosamples under continuous irradiation, ensuring accurate pH determination. More intriguingly, a CCD RGB camera serves as a collector to record luminescence signals, further promoting commercial feasibility. The successful application of CTS UCNPs on sensors indeed realizes blue/red ratiometric measurement towards pH under 808 nm irradiation, also pointing out a novel way for pH sensors with high sensitivity and accuracy.
研究领域:
生物医学工程
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材料科学
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分析化学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2019
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IF 2.687
Huazhen Liao,Song Ye,Yanling Shi,Deping Wang
Small size optical-magnetic bifunctional upconversion nanoparticles (UCNPs) that can be effectively triggered by 808 nm exhibit distinct advantages of improved tissue penetrating depth, minimized overheating effect, possible for multimodal imaging and high clearance rate, which therefore are considered as desirable candidates for bioapplications. In this research, the 808 nm triggered sub-20 nm β-NaYF 4 :Yb 3+ /Er 3+ @NaGdF 4 :Yb 3+ /Nd 3+ @NaGdF 4 active-core@active-shell@inert-shell structured UCNPs with optical and magnetic bifunctional properties were developed by seed-mediated growth method with NaOA as sodium source instead of the generally used NaOH. Through optimizing Nd 3+ doping concentration and outermost NaGdF 4 inert-shell thickness, the optical-magnetic bifunctional core-shell-shell structured UCNPs exhibited strong UC emission intensity and improved magnetic property . Furthermore, the core-shell-shell NPs were validated to be no cytotoxicity by cell viability assessment. Therefore, this research may open a general avenue for the synthesis of small size multifunctional UCNPs for practical bioapplications without overheating.
研究领域:
纳米材料科学
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生物医学工程
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产品关联
DOI
高影响因子
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