SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2020
·
IF 3.232
Hongqi Chen,Wen Wang,Changchun Ji,Lun Wang
The core–shell NaGdF 4 :Yb,Er@NaGdF 4 :Yb,Nd upconversion nanoparticles (UCNPs) were successfully obtained with the method of co-precipitation, and the water-solubility of UCNPs was improved by the ligand exchange reaction between nitrosyl tetrafluoroborate (NOBF 4 ) and nanoparticles. The IR-783 dye with negative charge and NOBF 4 -UCNPs with positive charge can bind together by electrostatic action to sensitize UCNPs through the energy transfer from IR-783 to UCNPs. However, with the presence of Na 2 S (a commonly used H 2 S donor), a highly selective reaction between H 2 S and IR-783, which destoried the structure of IR-783 and blocked the energy transfer, thus led to the quenching of luminescent intensity. Based on this, a sensing system for determination of H 2 S has been constructed successfully. The linear range of H 2 S detection by this system is 0.5–15 μM, and the detection limit is 34.17 nM. Furthermore, the dye-sensitized core–shell NaGdF 4 :Yb,Er@NaGdF 4 :Yb,Nd upconversion nanoprobe was applied to real sample analysis with satisfactory results.
研究领域:
分析化学
·
纳米技术
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2021
·
IF 5.097
Leilei Sun,Sisi Shi,Hongchao Geng,Yao Huang,Yan Qiao,Jie Song,Lan Yang,Craig A. Grimes,Xinxin Feng,Qingyun Cai
Bacterial infections are a serious ongoing threat to human health. As such, within the context of modern technology, there is an urgent need to develop fluorescent probes suitable for diagnosing bacterial infections in vivo. Herein, we synthesize NaGdF4:Nd@NaGdF4 core-shell down-conversion nanoparticles (DCNPs) demonstrating excellent emission intensity in the second near-infrared (NIR-II) window for use as fluorescent probes to enable high-quality imaging of pathogenic infections. The fluorescent probe is covalently linked with vancomycin (Van), which specifically binds to Gram-positive bacteria such as S. aureus. Both in vitro detection and in vivo imaging results show that the Van-modified NIR-II fluorescent probe can distinguish Gram-positive from Gram-negative bacteria with a high degree of selectivity. Biocompatibility is verified by MTT assay and histological analyses.
研究领域:
生物医学工程
·
材料科学
·
感染性疾病诊断
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2021
·
IF 3.08
Rangwei Meng,Zhiyuan He,Xuanhui Luo,Chi Zhang,Mengwei Chen,Halfei Lu,Yingping Yang
In this study, NaGdF 4 :Yb 3+ , Er 3+ @NaGdF 4 :Eu 3+ (NGEY@NGE) core-shell rare earth nanoparticles are prepared by a simple hydrothermal method . After testing, the emission peaks are observed at 415, 525, 540 and 660 nm with an excitation light of 980 nm due to the up-conversion luminescence from rare-earth nanoparticles . Under light excitation at 395 nm, the rare-earth nanoparticles undergo down-conversion luminescence with emission peaks at 590, 610 and 695 nm. The resulting nanoparticles are introduced into the TiO 2 mesoporous layer of hole-conductor-free perovskite solar cells (PSCs) based on carbon counter electrodes to broaden the spectral response of the cells from the visible range to the near-infrared and near-ultraviolet regions, which can guarantee a high light absorption efficiency and corresponding accelerated generation of electron-hole pairs. The results suggest that the mixing of NGEY@NGE nanoparticles into mesoporous TiO 2 layer improves the power conversion efficiency of PSCs to 14.21%, which is 10.6% higher than that of the control cells, which can pave an effective way to improve the performance of PSCs with a broadened response range.
研究领域:
材料科学
·
纳米技术
·
太阳能
·
光电
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2017
·Vol. 19
·期 26
·3600-3606
·
IF 3.474
Suli Wu,Xiaoqian Sun,Zhipeng Meng,Shufen Zhang
Doping, incorporating appropriate and functional atoms or ions into host lattices of colloid nanoparticles, is an important approach to modifying the shapes and sizes of nanoparticles and endowing them with new and useful properties. Herein, we demonstrate a “core–shell” synthetic strategy to control the shape of core–shell structured NaGdF4 upconversion nanoparticles (UCNPs) by introducing an impurity dopant in the core region. We introduced Cr3+ ions in the core region of NaGdF4 to synthesize “Jasminum sambac flower” shaped non-classic core–shell NaGdF4:Cr3+@NaGdF4:Yb3+,Tm3+ UCNPs. First of all, the effect of doping concentration on the shape of NaGdF4 core was investigated. Then, the core–shell strategy was applied to obtain a shape-controlled hierarchical nanostructure, and the effects of Cr3+ concentration on the phases, shapes and sizes of the products were investigated in detail. TEM images indicate that NaGdF4:Cr3+@NaGdF4:Yb3+,Tm3+ nanocrystals with Cr3+ concentration of 40–50% show highly uniform “Jasminum sambac flower” shaped structures. TEM images and XRD patterns of NaGdF4:Cr3+@NaGdF4:Yb3+,Tm3+ at different reaction times indicate that, initially, the flower shaped products are cubic phase and the size of the flowers is about 50 nm; with an increase of the reaction time, the cubic phase nanocrystals discompose to small ones and then transform to a bigger hexagonal phase “Jasminum sambac flower”. This “core/shell” doping strategy presents a general route to achieving controlled morphology in lanthanide-doped nanocrystal systems.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2019
·
IF 0
Peng Du,Weiguang Ran,Yafei Hou,Laihui Luo,Weiping Li
The Eu3+-activated NaGdF4 nanorods were achieved through a simple precipitation procedure at ambient temperature. With the irradiation at 396 nm, the designed nanorods exhibited visible red light with admirable color purity of 90.5% and the optimal doping concentration was 50 mol %. The concentration quenching mechanism was revealed to be decided by dipole–quadrupole interaction and the critical distance was 11.14 Å. The optical transition parameters, which were estimated from Judd-Ofelt theory, of the Eu3+ ions were obtained to confirm its local symmetry behaviors. Moreover, the emission spectra of the designed nanorods at diverse temperatures were used to identify its thermal quenching performance. In comparison with that of the Y2O3:Eu3+ compound, the emission intensity of the Eu3+-activated NaGdF4 nanorods with optimum doping content was 2.47 times higher and its internal quantum efficiency was around 62.3%. Furthermore, the developed white light-emitting diode device, which was constructed by resultant nanorods, green-emitting phosphor (i.e., (Ba,Sr)2SiO4:Eu2+), blue-emitting phosphor (i.e., BaMgAl10O17:Eu2+), and a near-ultraviolet chip, exhibited admirable colorific properties (i.e., good color coordinates, low correlated color temperature, high color rendering index). These achieved features implied that the NaGdF4 nanorods doped with Eu3+ ions were sutiable red-emitting platforms for indoor illumination.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
JOURNAL OF MODERN OPTICS
·
2024
·
IF 1.2
Hui Ying Zhang,Wan Ying Xie,Peng Zhang,Xiao Hui Li,Zian Cheak Tiu
In this work, NaGdF4: 20%Yb, 2%Er microcrystals with varying contents of Cr3+ doping were obtained by conventional hydrothermal process. The microcrystal phase structure, morphology, upconversion luminescence mechanism, as well as temperature sensing behaviour under different treatment methods were researched. Based on the thermally coupled 2H11/2 and 4S3/2 levels of Er3+ and the dependence of fluorescence intensity ratio (FIR) on temperature, the optical temperature sensing behaviour of micrometer crystals were experimentally demonstrated. The NaGdF4: 20%Yb, 2%Er, 7%Cr microcrystals treated with high-temperature annealing show the best temperature sensing behaviour within the temperature span of 298–498 K. NaGdF4: 20%Yb, 2%Er, 7%Cr microcrystals with high temperature annealing presented the feasibility and promising properties for optical temperature sensing. The endeavour of emerging materials could lay the groundwork for future sustainable photonics engineering industrial growth.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2016
·
IF 1.86
Jiangyun Dai,Guoying Feng,Jiajia Yin,Chao Yang,Xianheng Yang,Hua Zhang,Hong Zhang,Shouhuan Zhou
NaGdF 4 nanocrystals with controlled shapes were synthesized in an ethylene glycol/deionized water hydrothermal reaction system. Through adjusting the solvent composition, the nanocrystals with nanosphere-, nanotube-, and nanorod-like morphology have been selectively synthesized. The change in the nucleation speed, the growth rates in different crystallographic direction and the aggregation driving forces induced different morphologies of the resulting nanocrystals. A possible mechanism of shape evolution depending on solvent composition was proposed. Photoluminescence spectra of NaGdF 4 :Nd 3+ nanocrystals exhibited characteristic emission of Nd 3+ using an excitation wavelength of 794 nm. Moreover, the nanotube-like nanocrystals exhibited the strongest fluorescence intensity and longest fluorescence decay time.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2015
·
IF 4.772
Yan Song,Guixia Liu,Xiangting Dong,Jinxian Wang,Wensheng Yu,Jingmei Li
Multifunctional nanomaterials possessing upconversion luminescence, magnetic, and photothermal properties show promising applications in biology and medicine. In this study, a new kind of luminescent-magnetic-thermal core–shell hybrid nanocomposite was fabricated combining rare earth Yb3+ and Er3+ ions doped NaGdF4 nanocrystals as shell layer materials and gold nanorods (AuNRs) as cores. The structure, morphology, composition, and properties of the multifunctional hybrid nanocomposites were characterized by X-ray powder diffraction, transmission electron microscopy, energy dispersive spectroscopy, upconversion photoluminescence spectra, vibrating sample magnetometer, sensitive thermometer, and cytotoxicity assessment, respectively. The multifunctional hybrid nanocomposites have rodlike morphology and core–shell structure. The uniform NaGdF4/Yb3+,Er3+ shell with a thickness of around 4.5 nm was coated on the surface of AuNRs with a length of 40 nm and a diameter of 12 nm. The AuNRs@NaGdF4/Yb3+,Er3+ multifunctional nanocomposites provide an excellent upconversion emission under excitation at 980 nm and a superparamagnetic behavior with magnetic susceptibility of 8.0 × 10–5 emu·g–1·Oe–1 at 300 K and saturation magnetization value of 102 emu·g–1 at 2 K. More significantly, when AuNRs@NaGdF4/Yb3+,Er3+ aqueous suspensions of 100 μg·mL–1 were irradiated by a 980 nm NIR laser for 10 min, the temperature was significantly elevated to 48 °C. At the same time, the temperature of photothermal transduction can be easily controlled by adjusting the concentration of nanocomposites. Preliminary investigation of incubating with HeLa cells displays that the multifunctional nanocomposites exhibit a good biocompatibility. Moreover, the nanocomposites may be effectively utilized for bioimaging and photothermal therapy in living cells.
研究领域:
生物医学工程
·
纳米材料科学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2018
·Vol. 20
·期 23
·15835-15840
·
IF 3.906
Jianning Jin,Hua Yu,Liying Guo,Jinjin Liu,Bing Wu,Yuao Guo,Yuting Fu,Lijuan Zhao
β-NaREF4 (RE: rare earth metals) is a peculiar crystal due to its intriguing disordered structure. This crystal is usually considered to have an average structure with a space group of P-6 (174). However, a long-term contradiction existing in this system is that the luminescence characteristics do not match the corresponding theoretical predictions based on the average structure. To resolve this contradiction, we proposed a reasonable local structure model clearly showing the local symmetry of the cations based on the measurement of the extended X-ray absorption fine structure of β-NaGdF4. We also observed an intrinsic distortion in the disordered structure that resulted from the disordered arrangement of the Na+ and Gd3+ cations. Furthermore, using Eu3+ as a photoluminescence probe, we concluded that the breakdown in the crystallographic site symmetry originated from the intrinsic distortion of these crystals. This work provides a comprehensive explanation for the contradiction observed in this system and a foundation for further investigations to understand such disordered structures.
研究领域:
材料科学
·
晶体学
·
光谱学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 33
·期 2
·596-606
·
IF 2.478
Hu Haisheng,Jiang Qun,Li Yunfei,Liu Meitang
The K + -doped (Na 1− x K x )GdF 4 :Er 3+ ,Yb 3+ upconversion materials were successfully synthesized by solvothermal method. The doping of K + was testified to have great influences on improving upconversion properties as it directly affects the morphology of the material matrix. In addition, by coating the doped material with a homogeneous shell layer, a newly developed core–shell (Na 0.9 K 0.1 )GdF 4 :Er 3+ ,Yb 3+ @NaGdF 4 nanomaterials were produced. Surprisingly, its light emission intensity was 2 times of that for the uncoated material, although the crystal structure and the emission color of the nanoparticles did not change. The upconversion mechanism has also been studied, and the results show that there is a two-photon mechanism of (Na 1− x K x )GdF 4 :Er 3+ ,Yb 3+ . The work provides a new strategy for enhancing the luminescence density of upconversion materials by coating a homogeneous shell after doping.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2016
·Vol. 9
·期 1
·91-98
·
IF 7.76
Jing Liu,Guanying Chen,Shuwei Hao,Chunhui Yang
The ability to fabricate lanthanide-doped upconversion nanocrystals (UCNCs) with tailored size and emission profile has fuelled their uses in a broad spectrum of biological applications. Yet, limited success has been met in the preparation of sub-6 nm UCNCs with efficient upconversion photoluminescence (UCPL), which enable high contrast optical bioimaging with minimized adverse biological effects entailed by size-induced rapid clearance from the body. Here, we present a simple and reproducible approach to synthesize a set of monodispersed hexagonal-phase core NaGdF4:Yb/Ln (Ln = Er, Ho, Tm) of ∼3–4 nm and core/shell NaGdF4:Yb/Ln@NaGdF4 (Ln = Er, Ho, Tm) UCNCs of ∼5–6 nm. We show that the core/shell UCNCs can be up to ∼1000 times more efficient than the corresponding core UCNCs due to the effective suppression of surface-related quenching effects for the core. The observation of prolonged PL lifetime for the core/shell than that for the core UCNCs demonstrates the role of the inert shell layer for the protection of the core. The achievement of sub-6 nm NaGdF4 UCNCs with significantly improved luminescence efficiency constitutes a solid step towards high contrast UCPL optical imaging with secured biological safety.
研究领域:
材料科学
·
生物医学工程
·
光学
✓ 已验证
DOI
高影响因子
OPTICS AND LASER TECHNOLOGY
·
2017
·
IF 2.109
Jiangyun Dai,Guoying Feng,Shutong Wang,Hong Zhang,Shengyu Dai,Shouhuan Zhou
By using femtosecond-pulsed laser to ablate the larger nanosized target in liquid, stable transparent NaGdF 4 :Nd 3+ colloid has been successfully fabricated. The X-ray diffraction (XRD) spectra reveal that the colloidal nanoparticles remain the hexagonal phase crystal structure of NaGdF 4 powder target. SEM and TEM images results indicate that the size of these colloidal nanoparticles decreases sharply. FT-IR results indicate that the number of O–H and C–H groups on the surface is decreased. The emission properties of the colloid have been investigated using 794 nm pulsed wave laser radiation , and it is found that the colloid exhibits near-infrared luminescent emissions in the spectral range of 850–1400 nm, and the decay time for 4 F 3/2 → 4 I 11/2 (1058 nm) Nd 3+ ion transitions is lengthened than that of powder target, these results are probably due to the reduced nonradiative relaxation assisted by high energy oscillators . The observed near-infrared emission of the stable transparent colloid makes it a good candidate for application in liquid laser .
研究领域:
材料科学
·
光学
✓ 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）