Science of Advanced Materials
·
2017
·
IF 1.671
Zhou Zhiping,Yu Yingsen,Sun Quanmin,Liu Xiaotang,Lei Bingfu,Yan Yun
In this work, up-conversion phosphor CaF2:Yb3
+, Er3+ was synthesized by the co-precipitation method. X-ray Diffraction (XRD) and Photoluminescence Spectra (PL) were used to characterize the samples. The effects of annealing temperature and
Yb3+ and Er3+ concentrations on the luminescence properties were discussed. Strong green and red light were obtained under 980 nm laser excitation, the optimal annealing temperature was 600 °C, while the optimal doping concentration was 8 mol% Yb3+ and
0.6 mol% Er3+. The green (540 nm and 552 nm) and red (652 nm and 669 nm) up-conversion luminescence peaks can be ascribed to the transitions of 4S3/2-4I15/2 and 4F9/2-4I15/2, respectively. The
up-conversion luminescence intensities of the green and red emitting peaks can be changed by adjusting the concentration ratio of Yb3+ and Er3+. Hence, it can potentially be used as the red light conversion agent. The dependence of up-conversion intensities (CaF2:Yb3+,
Er3+) on excitation power indicated that two-photon absorption processes were responsible for green and red luminescence.
研究领域:
材料科学
·
光学
·
光子学
✓ 已验证
DOI
高影响因子
BIOMATERIALS
·
2015
·
IF 8.557
Xiaoran Deng,Yunlu Dai,Jianhua Liu,Ying Zhou,Ping'an Ma,Ziyong Cheng,Yinyin Chen,Kerong Deng,Xuejiao Li,Zhiyao Hou,Chunxia Li,Jun Lin
Combining the multi-modal medical imaging with cancer therapy in one single system has attracted the great interests for theranostic purpose. In this paper, CaF 2 :Yb 3+ /Er 3+ /Mn 2+ -poly(2-Aminoethyl methacrylate) (UCHNs-PAMA) hybrid microspheres were successfully fabricated. The synthetic route to the nanocomposite based on a facile hydrothermal method for fabrication of hollow upconversion (UC) nanospheres at first and then post-filling the PAMA interiorly through photo-initiated polymerization. The UCHNs showed orange fluorescence under 980 nm near infrared (NIR) laser excitation , which provided the upconverting luminescence (UCL) imaging modality . Meanwhile, the presence of functional Mn 2+ and Yb 3+ offered the enhanced T 1 -weighted magnetic resonance (MR) and computed tomography (CT) imaging, respectively. Thanks to introducing amine groups-containing PAMA inside the hollow nanospheres, the Pt(IV) pro-drug, c,c,t-Pt(NH 3 ) 2 Cl 2 (OOCCH 2 CH 2 COOH) 2 (DSP), can be conveniently bonded on the polymer network to construct a nanoscale anti-cancer drug carrier. The UCHNs-PAMA-Pt(IV) nanocomposite shows effective inhibition for Hela cell line via MTT assay . In contrast, Pt(IV) pro-drug and UCHNs-PAMA microspheres behave little cytotoxicity to Hela cells. This should be attributed the fact that the anti-cancer ability can be recovered only when Pt(IV) pro-drug was reduced to Pt(II)-drug in cellular environment. Furthermore, the in vivo experiments on small mice also confirm that the hybrid microspheres have relatively low toxic side effects and high tumor inhibition rate. These findings show that the multifunctional hybrid microspheres have potential to be used as UCL/MR/CT tri-modal imaging contrast agent and anti-cancer drug carriers.
研究领域:
纳米医学
·
生物材料
·
癌症治疗
·
医学影像学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
OPTICAL MATERIALS
·
2018
·
IF 2.32
Rui Wang,Maohui Yuan,Chaofan Zhang,Hongyan Wang,Xiaojun Xu
Transition metal ions (e.g. Mn 2+ ) and lanthanide co-doped upconversion (UC) materials have attracted wide attention in recent years due to their promising application in multicolor display. Here, we report the hydrothermal synthesis and characterization of Mn 2+ doped monodisperse CaF 2 :Yb 3+ /Ho 3+ microspheres . The results of X-ray diffraction (XRD) revealed that Mn 2+ doping does not change the cubic phase of CaF 2 material but will lead to diffraction peaks shifting slightly towards higher angle due to the substitution of larger Ca 2+ by the relatively smaller Mn 2+ . Under the excitation of 980 nm continuous wave (CW) laser, these microspheres exhibit green-yellow-red tuning colors and remarkable enhancement of both red to green ratio (R/G) and red to blue ratio (R/B) when increasing Mn 2+ concentration from 0 to 30 mol%. The energy migration process between Ho 3+ and Mn 2+ was proposed and supported by time-decay and power dependence measurements of Ho 3+ UC emission. These upconversion materials may have potential applications in optical devices , color display, nanoscale lasers and biomedical imaging.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
NANO
·
2022
·
IF 1.438
Sisi Shi,Hongchao Geng,Leilei Sun,Yao Huang,Qingyun Cai
A turn-on fluorometric probe is designed for the determination of ascorbic acid (AA) based on the inner filter effect (IFE) between CaF 2 : Yb 3 + , Er 3 + upconversion nanoparticles (CaF 2 : Yb 3 + , Er 3 + NPs) and the oxidized 3, 3 ′ , 5, 5 ′ -tetramethylbenzidine (oxTMB). The colorless TMB can be oxidized by H 2 O 2 / Cu 2 + to blue oxTMB. Under 980 nm photoexcitation, CaF 2 : Yb 3 + , Er 3 + NPs can emit red light, which can be absorbed by the blue oxTMB, leading to the fluorescence quenching at 657 nm. As AA can reduce the blue oxTMB to colorless TMB, the fluorescence at 657 nm can be recovered with the addition of AA, which can accomplish the detection towards AA. The linear detection range of AA is from 1 to 30 μ M, and the limit of detection (LOD) of AA is 0.1 μ M.
研究领域:
分析化学
·
生物医学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 23
·13201-13206
·
IF 3.049
Xu Yang,Maohui Yuan,Rui Wang,Xiaofan Zhao,Zining Yang,Kai Han,Hongyan Wang,Xiaojun Xu
Harnessing the color tuning capability of upconversion nanoparticles (UCNPs) is of great significance in the field of advanced bioimaging and color display. Here, we report the tunable size and upconversion luminescence (UCL) multicolor in CaF2:Yb3+/Ho3+/Ce3+ UCNPs, which were synthesized by a facile hydrothermal method. It was found that the size of these UCNPs could be controlled (from 600 to 30 nm) by varying the concentration of Ce3+ ions. Under the excitation of a 980 nm continuous-wave (CW) laser, the UCL color of these UCNPs can be tuned from green to red as the doped Ce3+ ions gradually increase from 0 to 10 mol% and the red-to-green (R/G) ratio is enhanced remarkably. It is suggested that the cross-relaxation (CR) processes between Ho3+ and Ce3+ ions contribute to the tunable multicolor and enhancement of the R/G ratio. The mechanism of these processes is well supported by the time-resolved decay and near infrared (NIR) emission measurements.
研究领域:
材料科学
·
生物成像
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
·
2021
·
IF 3.995
Zhiyu Liu,Jianhe Tang,Congcong Piao,Xing Zhang,Xiaochen Qi,Ying Tian,Dawei Fang,Jun Wang
A novel Z-scheme CaF 2 :Yb 3+ ,Er 3+ @ZnTiO 3 /Au/CdS photocatalyst has been prepared. In this system, an excellent up-conversion luminescent agent, CaF 2 :Yb 3+ ,Er 3+ , is introduced to broaden the light response range. The Au surface plasmon resonance effect endows the system with highly efficient charge transfer. The photocatalytic activity of the Z-scheme CaF 2 :Yb 3+ ,Er 3+ @ZnTiO 3 /Au/CdS photocatalyst has been evaluated in the degradation of norfloxacin (NOR) with simultaneous hydrogen production . Some influencing factors, such as solar light irradiation time, sacrificial agent concentration, and number of reuse cycles, are discussed. The emission spectrum and energy conversion mechanism of CaF 2 :Yb 3+ ,Er 3+ have also been studied. The prepared photocatalyst facilitated a significant degree of degradation (92.05%) of NOR and considerable hydrogen production (513.39 μmol/g) under solar light irradiation for 5.0 h. Moreover, it showed high stability in photocatalytic NOR degradation with simultaneous hydrogen production over five cycles. A possible mechanism for photocatalytic degradation of NOR with simultaneous hydrogen production promoted by the Z-scheme CaF 2 :Yb 3+ ,Er 3+ @ZnTiO 3 /Au/CdS photocatalyst is proposed.
研究领域:
环境科学
·
材料科学
✓ 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）