MATERIALS RESEARCH BULLETIN
·
2015
·
IF 2.288
Xiang-Yang Chen,Zhi-Jun Zhang,Ang Feng,Meng Xu,Jing-Tai Zhao,Fang-Fang Xu
Density functional theory calculations on monoclinic Lu 2 WO 6 is carried out using the Cambridge Sequential Total Energy Package code. The result indicates that Lu 2 WO 6 is a broad band gap semiconductor with an indirect band gap of 3.13 eV. Eu ions are trivalency and the average coordination number is 7.6(5), indicating that the site of Lu is occupied by Eu. The activation energy Δ E is calculated as 0.314 eV. In addiation, the thermal quenching mechnism of Eu-activated Lu 2 WO 6 and the different concentration quenching mechanisms for 5 D 0 and 5 D 1 emissions of Eu ions have been proposed.
研究领域:
材料科学
·
物理学
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产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2023
·Vol. 10
·期 22
·6701-6710
·
IF 7
Fangyi Zhao,Yuhe Shao,Zhen Song,Quanlin Liu
Luminescence concentration quenching and thermal quenching are closely related to the energy transfer (ET) process between optically active ions. Herein, we utilize the structural confinement effect in Sr9Ga(PO4)7 (SGP) to selectively control ET pathways so as to suppress luminescence concentration and thermal quenching. In the Fe3+-doped SGP compound, the relatively large Fe3+–Fe3+ distances can inhibit the ET between Fe3+ ions, leading to weak concentration quenching. The Sr9Ga0.8(PO4)7:0.2Fe3+ (SGP:0.2Fe3+) phosphor exhibits the highest near-infrared (NIR) luminescence intensity, and the emission intensity for 50% and 100% Fe3+-doped SGP phosphors is 73.46% and 18.25% of that for the optimal sample SGP:0.2Fe3+, respectively. Upon co-doping Yb3+ into SGP:0.2Fe3+, Fe3+–Yb3+ distances are much shorter than those of Fe3+–Fe3+, causing energy to quickly migrate from the quenching center Fe3+ to the thermally stable center Yb3+. The thermal stability of SGP:0.2Fe3+,0.07Yb3+ is greatly enhanced compared to SGP:0.2Fe3+. This study provides a strategy for enhancing NIR luminescence through utilizing structural confinement to control ET pathways toward suppressing concentration and thermal quenching. Finally, we demonstrate the potential applications of SGP:0.2Fe3+ and SGP:0.2Fe3+,0.07Yb3+ phosphors in night vision and optical thermometry fields.
研究领域:
材料科学
·
光学材料
·
固体发光
·
无机非金属材料
·
光电子学
✓ 已验证
DOI
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 9
·1-8
·
IF 5.479
Peng Yage,Dong Wenfei,Wan Le,Quan Xiaosai
Molybdenum disulfide quantum dots (MoS 2 QDs) are used in a fluorometric method for the determination of folic acid (FA) based on fluorescence quenching. The MoS 2 QDs synthesized by a hydrothermal method possess bright blue fluorescence (with excitation/emission maxima of 325/415 nm), quantum yield of 3.7%, and excellent storage stability in solution (30 days in the refrigerator). Their fluorescence is quenched by FA, and intensity decreases linearly in the 0.1 to 125 μM FA concentration range. The detection limit is 0.1 μM (at S/ N = 3), and the relative standard deviation (for n = 5) is 2.8% for 25 μM concentrations of FA. Studies on the quenching mechanism suggest that the effect is due to static quenching. The FA in commercial FA tablets was successfully determined.
Schematic representation of the hydrothermal method for the preparation of molybdenum disulfide quantum dots (MoS 2 QDs) with about 2.7 ± 0.5 nm diameter using Na 2 MoO 4 and L-cysteine as Mo and S sources, and the fluorescence method for the determination of folic acid (FA) based on fluorescence quenching of MoS 2 QDs.
研究领域:
分析化学
·
生物医学
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产品关联
DOI
PubMed
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2012
·Vol. 168
·期 3
·592-603
·
IF 1.943
Fan Yunchang,Yan Jinlong,Zhang Sheli,Li Junhai,Chen Dong,Duan Peigao
The interaction between papain and two typical ionic liquids (ILs), 1-octyl-3-methylimidazolium chloride ([C 8 mim]Cl) and 1-butyl-3-methylimidazolium chloride ([C 4 mim]Cl), was investigated by using fluorescence spectroscopy technique at a pH value of 7.4. The results suggested that ILs could quench the intrinsic fluorescence of papain probably via a static quenching mechanism. The binding constants were determined by employing the fluorescence quenching method. They were very small compared with that of volatile organic solvents, indicating that only very weak interaction between ILs and papain existed. The Gibbs free energy change (∆ G ), enthalpy change (∆ H ), and entropy change (∆ S ) during the interaction of papain and ILs were estimated. Negative values of these parameters indicated that the interaction between ILs and papain was a spontaneous process, also implying that hydrogen bonding and van der Waals forces played important roles in the interaction processes.
Three-dimensional fluorescence spectrum of papain (0.2 g L -1 )
研究领域:
生物化学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2014
·
IF 2.129
Jinhua Zhu,Lanlan Chen,Yingying Dong,Jiazhong Li,Xiuhua Liu
In this work, the interaction of 5-Hydroxymethyl-2-furfural (5-HMF) with calf thymus DNA (ctDNA) under simulated physiological conditions (Tris–HCl buffer of pH 7.40), was explored by UV absorption spectroscopy, fluorescence spectroscopy and molecular modeling method, using ethidium bromide (EB) as a fluorescence probe of DNA. The fluorescence quenching mechanism of EB–ctDNA by 5-HMF was confirmed to be a static quenching, which derived from the formation of a new complex. The binding constants of 5-HMF with DNA in the presence of EB were calculated to be 2.17 × 10 3 , 4.24 × 10 3 and 6.95 × 10 3 L mol −1 at 300, 305 and 310 K, respectively. The calculated thermodynamic parameters, enthalpy change Δ H and entropy change Δ S , suggested that both hydrophobic interactions and hydrogen bonds played a predominant role in the binding of 5-HMF to DNA. According to the UV absorption spectroscopy and melting temperature ( T m ) curve results, the binding mode of 5-HMF with DNA was indicative of a non-intercalative binding, which was supposed to be a groove binding. The molecular modeling results showed that 5-HMF could bind into the hydrophobic region of ctDNA and supported the conclusions obtained from the above experiments.
研究领域:
生物化学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2022
·
IF 3.428
Qingmei Zhang,Songjie He,Kaiwen Zheng,Lupeng Zhang,Lihua Lin,Fenghua Chen,Xiujuan Du,Bing Li
A growing interest has emerged in carbon dot (CDs) fluorescent probes, as they are non-destructive, non-contact, sensitive, fast, and low-cost. However, the low fluorescence quantum yield (QY) and the uncertainty of fluorescence quenching mechanism are the main bottlenecks restricting its application. Here, we used mustard seeds as carbon source, CDs were synthesized by a simple hydrothermal method without further surface treatment with the QY reached a value as high as 17.92 % in 468 nm excitation energy. As a label-free fluorescent probe, CDs can be used to sense Fe 3+ ions in environmental water and human oral keratinocytes (Hok) cells, with a detection limit of 0.51 μM and the linear range of 0–75 μM. Moreover, we have conducted an in-depth study on the mechanism of fluorescence quenching of CDs caused by Fe 3+ ions. Our study provides powerful evidences that the mechanism of fluorescence quenching to Fe 3+ ions is a synergistic effect of static quenching (SQ) and aggregation-induced effect (AIE), which accompanied by forming a non-fluorescent ground state complex between CDs and Fe 3+ ions. This work promises to provide new ideas for the most appropriate detection strategy and design the best performing sensor, allowing their effective application in the sensing field.
研究领域:
材料科学
·
环境科学
·
生物医学
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产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Li Liu,Maomin Peng,Ke Xu,Hong Xia,Xitian Peng,Lijun Peng,Youxiang Zhou,Jin Z. Zhang
Highly stable and photoluminescent methylammonium lead halide perovskite quantum dots (MAPbBr3 PQDs) have been synthesized and applied for the fluorescence quenching detection of clothianidin in fruit and vegetable samples. Characterizations using different techniques, including photoluminescence (PL), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and time-resolved PL (TRPL), show that static quenching is the dominant fluorescence quenching mechanism of MAPbBr3 PQDs with clothianidin. Hydrogen bonds or van der Waals forces play major roles in the MAPbBr3 PQDs–clothianidin interaction. Under optimized conditions, the relative PL intensity of MAPbBr3 PQDs is linear to the concentration of clothianidin in the 0.0 and 20.0 mg/L range with a detection limit of 0.17 μg/kg. Excellent recoveries of 79.5–115.4% were acquired for radish and banana samples with a relative standard deviation below 9.4%. These results indicate that PQDs can be used for qualitative and quantitative identification of clothianidin, providing an effective detection method for risk prevention and control of neonicotinoid pesticide residues in agricultural products.
研究领域:
分析化学
·
食品安全
·
环境科学
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产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2023
·
IF 4.4
Yuting Wang,Fengming Zhang,Jia Liu,Bin Yang,Yue Yuan,Yanyan Zhou,Shuyun Bi
A method was established for detecting the content of nitrofurazone (NFZ) by fluorescence quenching of N-Acetyl-L-Cysteine (NAC) coated cadmium telluride quantum dots (CdTe QDs). By means of transmission electron microscopy (TEM) and multispectral methods such as fluorescence and ultraviolet visible spectra (UV–vis), the synthesized CdTe QDs were characterized. The quantum yield ( φ ) of CdTe QDs was measured as 0.33 by reference method. The CdTe QDs had a better stability, the RSD of fluorescence intensity was 1.51% in three months. NFZ quenching the emission light of CdTe QDs was observed. The analyses of Stern-Volmer and time-resolved fluorescence suggested the quenching was static. The binding constants ( K a ) between NFZ and CdTe QDs were 1.14 × 10 4 (293 K), 0.74 × 10 4 (303 K) and 0.51 × 10 4 (313 K) L mol −1 . The hydrogen bond or van der Waals force was the dominated binding force between NFZ and CdTe QDs. The interaction was further characterized by UV–vis absorption as well as Fourier transform infrared spectra (FT-IR). Using fluorescence quenching effect, a quantitative determination of NFZ was carried out. The optimal experimental conditions were studied and determined as following: pH was 7 and contact time was 10 min. The effects of reagent addition sequence, temperature and the foreign substances including some metals (Mg 2+ ; Zn 2+ ; Ca 2+ ; K + ; Cu 2+ ), glucose, bovine serum albumin (BSA) and furazolidone on the determination were studied. There was a high correlation between the concentration of NFZ (0.40 – 39.63 μg mL −1 ) and F 0 / F with the standard curve F 0 / F = 0.0262 c + 0.9910 ( r = 0.9994). The detection limit (LOD) reached 0.04 μg mL −1 (3 S 0 / S ). The contents of NFZ in beef and bacteriostatic liquid were detected. The recovery of NFZ was 95.13% – 103.03% and RSD was 0.66% – 1.37% ( n = 5).
研究领域:
分析化学
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2017
·
IF 2.536
Haiyan Qin,Diao Ma,Jianxiu Du
The interaction between fluorescent gold nanoclusters (AuNCs) and gold nanoparticles (AuNPs) has been investigated. It was observed that the fluorescence of AuNCs was remarkably quenched when direct contact with AuNPs. The fluorescence quenching of AuNCs by AuNPs was dynamic quenching and exhibited size-dependent property. A larger size of AuNPs displayed a stronger quenching effect and gave a larger quenching constant. When a silica spacer shell was introduced between AuNPs and AuNCs, a fluorescence enhancement of AuNCs by [email protected] 2 NPs was observed. The fluorescence enhancement was strongly dependent on the separation distance between the AuNPs and the AuNCs. A maximal enhancement of 3.72 times was observed when [email protected] 2 NPs have a silica shell thickness of 12 nm. This nanocomposite consisting of relatively nontoxic AuNPs and AuNCs may have a potential application in developing novel fluorescent sensor.
研究领域:
纳米技术
·
材料科学
·
光学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2014
·
IF 2.129
Ruiyong Wang,Xiaogai Wang,Zhigang Li,Yuanzhe Xie,Lingling Yang,Jie Shi,Junbiao Chang
The binding of 4′-azido-2′-deoxyfluoroarabinocytidine (FNC) or analogs (cytidine and 5′-cytidylate monophosphate) to bovine serum albumin (BSA) was investigated by fluorescence, UV–vis absorption spectroscopy and molecular modeling. The three compounds quenched the intrinsic fluorescence of BSA and the results revealed the presence of static quenching mechanism. The positive Δ H and positive Δ S for the systems suggested that the hydrophobic forces stabilized the interaction between the compounds and protein. Results also showed that FNC was the weakest quencher.
研究领域:
生物化学
·
药物化学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2017
·Vol. 409
·期 22
·5327-5336
·
IF 3.431
Xu Xiangyu,Du Zhongyu,Wu Weihua,Wang Yunfei,Zhang Bo,Mao Xuyan,Jiang Liang,Yang Jie,Hou Shifeng
The interactions of triangular silver nanoprisms (TAgNPrs) with bovine serum albumin (BSA) were investigated using multiple spectroscopic techniques. A noticeable absorbance increase was noted in the peak ranges of 250 to 300 nm for BSA, and the intensity increased with the increasing concentration of TAgNPrs. Furthermore, a slight blue shift of the surface plasmon resonance band of TAgNPrs occurred, indicating that the protein absorbed on the TAgNPrs surface to form a bio-nano interface. Analysis of fluorescence quenching data using the Stern-Volmer method revealed that static quenching takes place with complex formation. Evaluation of thermodynamic parameter Δ G
θ for the binding processes indicated that the binding reaction was exothermic. Furthermore, the values of binding constant K revealed that the size of nanoparticles can affect the binding degree. The order of binding affinity is 43.7 nm > 36.2 nm > 25.1 nm. The competitive experiments of site markers (flufenamic acid and phenylbutazone) suggested that the binding site of TAgNPrs on BSA was located in the region of subdomain IIIA (Sudlow site II). In addition, the conformational changes of BSA by TAgNPrs were analyzed by using synchronous fluorescence spectra, circular dichroism, and three-dimensional fluorescence spectra.
The protein absorbed on the TAgNPrs surface to form a nanoparticle-protein corona
研究领域:
生物化学
·
纳米生物学
·
光谱学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL PHYSICS
·
2020
·
IF 1.771
Lizhi Zhao,Yaxiang Zhao,Rishun Li,Dihao Wu,Xingyu Xie,Hui Ye,Yuzhong Zhang,Qingping Xin
Metal-organic frameworks (MOFs) of copper-tetrakis-(4-carboxyphenyl)-porphyrin (CuTCPP) were prepared by a solvothermal route. The two-dimensional (2D) ultrathin nanosheets with larger specific surface area show higher adsorption capacity for rhodamine B (RhB), compared with the bulk MOF of CuTCPP. The binding mechanism of the 2D nanosheets with RhB was investigated based on spectroscopic methods . The results reveal that the fluorescence of RhB is efficiently quenched by 2D CuTCPP nanosheets , and the quenching mechanism is totally the static quenching by forming a ground state RhB-CuTCPP nanosheets complex with an apparent association constant of 3.953 × 10 3 M −1 . The interaction between RhB and CuTCPP nanosheets leads to the H-aggregate of RhB in the complex. Higher-order aggregate may also be involved in the complexation. Thermodynamic studies demonstrate that RhB-CuTCPP nanosheets interaction is a spontaneous process and driven by electrostatic and hydrophobic forces . The 2D CuTCPP nanosheets can be regenerated from the complex and used repeatedly.
研究领域:
材料科学
·
光谱学
·
环境科学
✓ 已验证
DOI
高影响因子
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