MICROCHIMICA ACTA
·
2017
·Vol. 185
·期 1
·1-9
·
IF 4.58
Cui Malin,Wang Chan,Yang Dapeng,Song Qijun
Fluorescent iridium nanoclusters (IrNCs) consisting of up to 7 Ir atoms were prepared by heating IrCl 3 in N,N-dimethylformamide. No other reagents are required. High resolution transmission electron microscopy (HRTEM) shows the IrNCs to be monodispersed with an average size of 0.9 ± 0.2 nm. They are well soluble in polar solvents and stable in these solvents for at least 6 months. Under photoexcitation with 365 nm light, they emit strong bluish green fluorescence with peaks that depend on the excitation wavelength and range from 530 to 650 nm. The fluorescence lifetime typically is 2.2 ns and the quantum yield is 8.3%. Fluorescence is quenched by Cr(VI) ion (chromate), and the emission peak is gradually red-shifted. According to the absorbance spectra of IrNCs in the presence and absence of Cr(VI) and Stern-Volmer quenching behavior study, static quenching is involved. Based on these findings, a selective assay was developed for the determination of Cr(VI). It has a linear response in the 0.1 to 100 μM chromate concentration range and a 25 nM detection limit. Fluorescent iridium nanoclusters (IrNCs), consisting of up to 7 Ir atoms, were prepared in N,N-dimethylformamide (DMF) solution without using any other reagents. Their fluorescence is statically quenched by Cr(VI).
研究领域:
分析化学
·
环境科学
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高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2015
·Vol. 15
·期 6
·4276-4284
·
IF 1.556
Zhu Yuanna,Yang Ping,Miao Yanping,Cao Yongqiang,Yang Yang
The photoluminescence (PL) quenching of thioglycolic acid (TGA)-capped CdTe quantum dots (QDs) by glutathione (GSH)-capped Au nanocrystals (NCs) were investigated via PL degradated measurement. It was found that the PL of the QDs with several sizes can be effectively quenched by GSH-Au
NCs. The size and PL peak wavelengths of QDs have no significant impact on the quenching processing. Through the characterizations of UV-visble absorption spectrum, Zeta potential and steady-state, and time-resolved fluorescence spectroscopy, it was proved that the PL quenching of the QDs
by GSH-Au NCs was attributed to static quenching caused by the formation of a QDs- Au complex. The binding parameters calculated from modified Stern–Volmer equation showed that the binding affinities between the GSH-Au NCs and CdTe QDs was in the order of 105 L ·mol−1,
which indicated that the binding force was larger and the effective quenching occurred. The thermodynamic parameters studies revealed that the binding was characterized by positive enthalpy and positive entropy changes and hydrophobic force played a major role for QDs-Au association. In addition,
all the quenching experiments were conducted in the phosphate-buffered saline (PBS) buffer solution at pH 7.4 and the investigation is expected to be applied in the biology.
研究领域:
材料科学
·
生物医学工程
·
化学
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高影响因子
JOURNAL OF FLUORESCENCE
·
2022
·Vol. 32
·期 6
·2343-2350
·
IF 2.525
Liu Tao,Zhang Shuai,Fan Xiaoyu,Yang Dou,Wang Min,Shao Xiaodong,Wang Shuhao,Yue Qiaoli
Carbon dots (CDs) were used to develop a sensitive sensing technique for detecting Cr(VI). CDs were made using a hydrothermal technique from citric acid and glutamic acid. These prepared CDs emitted blue fluorescence under excitation of 350 nm (λ em = 420 nm), and the fluorescence quantum yield was 48.41%. Transmission electron microscope was used to examine the morphology of the CDs, which had an average size of 2.21 ± 0.39 nm. The elementary composition and bonding structure of the CDs were conducted by XPS and FT-IR spectrum. Cr(VI) quenched the fluorescence of CDs through a static quenching effect and an inner filter effect, allowing Cr(VI) to be detected quantitatively. This approach was used to detect Cr(VI) in two samples of water, with the findings demonstrating that it is reliable and accurate. The fluorescence intensity change was linearly related to the concentration of Cr(VI) in the range from 0.5 to 400 μM, with the detection limit being 0.10 μM. This approach has the virtues of wide detection range, low cost and fast response. The strategy has a great application prospect for detecting Cr(VI) in practical samples.
研究领域:
分析化学
·
环境科学
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高影响因子
JOURNAL OF LUMINESCENCE
·
2024
·
IF 3.3
Fengjiao Yang,Bingyu Yang,Lixian He,Kezhen Qi,Alireza Khataee,Ya Yan
Metronidazole (MNZ) is a type of nitroimidazole antibiotic widely used in livestock feed. The extensive use, overuse, and misuse of MNZ have resulted in high levels of MNZ residues in animal products, posing serious health risks to people. Based on the effective fluorescence quenching capability of MNZ, a highly precise technique characterized by low-cost materials, low detection limit, and simple operational procedure was established to detect MNZ in eggs by modulating the fluorescence produced by AgInS 2 quantum dots (AIS QDs). The performance of the prepared sample was outstanding as the linear range was 0.25–80.00 μg/mL with a detection limit (LOD) of 0.166 μg/mL and R 2 = 0.9996, having an average recovery of MNZ in egg white ranged from 94.88 % to 102.39 %. This detection method has the advantages of a wide detection range, high sensitivity, high accuracy, excellent selectivity , and simple operability, and it can be used to detect MNZ in eggs after further study. The fluorescence quenching mechanism of AIS QDs by MNZ is speculated as a dynamic quenching mechanism of light-induced electron transfer .
研究领域:
分析化学
·
食品安全
·
生物医学
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DOI
高影响因子
JOURNAL OF MATERIALS RESEARCH
·
2014
·Vol. 29
·期 5
·633-640
·
IF 1.815
Jun Yao,Mei Yang,Yixiang Duan
Highly luminescent CdTe quantum dots (QDs) were prepared through a fast, facile, and straightforward method. The crystal structure, particle size, optical properties as well as molecular interactions between the CdTe QDs and their capping agents have been investigated by high resolution transmission electron microscopy, selected area electron diffraction, scanning transmission electron microscope–energy dispersive x-ray spectroscopy, UV-vis absorption, photoluminescence, and Fourier transform infrared, respectively. The results illustrate that the CdTe nanoparticles exhibit cubic structure and the average crystallite size is 2.3 nm. Meanwhile, fluorescence and UV-vis spectroscopic techniques were used to study the interaction between hemin and the well-defined CdTe QDs. In weak basic media, the fluorescence of CdTe QDs was quenched notably by hemin, and the quenching values were proportional to the concentration of the quencher in a certain range. The quenching mechanism was discussed to be a dynamic quenching procedure, collisional process, and hemin as a fluorescence quencher donated its electron to CdTe QDs to occupy the hole and accordingly disrupted the electron–hole recombination.
研究领域:
纳米材料科学
·
生物分析化学
·
光学
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DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2025
·
IF 3.6
Feng Gu,Zhaomin Cao,Yingzheng Liu,Di Peng
Polymer–ceramic pressure-sensitive paints (PC-PSPs) enable time-resolved pressure-field measurements with high spatial resolution. Their porous binder, formed by a large proportion of ceramic particles and a small amount of polymer, facilitates oxygen diffusion, ensuring a rapid response. However, the low polymer concentration in PC-PSPs leads to severe dynamic self-quenching of luminescence, which is further complicated by the microenvironment heterogeneity induced by the high concentration of ceramic particles. While these factors significantly deteriorate the static sensing performance of PC-PSPs, the underlying mechanisms remain poorly understood. To address this gap, this paper introduces a photophysical model for the quenching mechanism in PC-PSPs, considering the dynamic self-quenching effect and microenvironment heterogeneity. The proposed model is verified based on experimental results of PC-PSPs with varying polymer-to-ceramic particle ratios. The effects of dynamic self-quenching and microenvironment heterogeneity on pressure sensitivity, response time, and photodegradation are analyzed based on theoretical analysis and experimental results. The findings can provide valuable reference for the design and optimization of PC-PSPs.
研究领域:
材料科学
·
光学工程
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DOI
高影响因子
CHEMISTRY & BIODIVERSITY
·
2024
·Vol. 21
·期 7
·e202400634
·
IF 2.3
Yongshan Ma,Qingxiang Guan,Jingcheng Cui,Tianyi Jiang,Yanyan Zhu,Fengxia Zhang,Guangxiang Ma
Molybdenum disulfide nanoflowers (MoS 2 NFs) were prepared by hydrothermal method. The prepared MoS 2 NFs was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), specific surface areas, Raman and X-ray photoelectron spectroscopy (XPS). The characterization results show that the flower-like spherical MoS 2 is composed of many ultra-thin nanosheets with an average diameter of about 300–400 nm. MoS 2 NFs also exhibits excellent UV–vis absorption and high fluorescence intensity. In order to explore the biological behavior of MoS 2 NFs, the interaction between MoS 2 NFs and bovine serum albumin (BSA) was studied by UV–Vis absorption, fluorescence, synchronous fluorescence spectra, and cyclic voltammetry. The results of absorption and fluorescence show that MoS 2 NFs and BSA interact strongly through the formation of complexes in the ground state, and the static quenching is the main mechanism. The Stern–Volmer constant and the quenching constant was calculated about 3.79×10 7 L mol −1 and 3.79×10 15 L mol −1 s −1 , respectively. The synchronous fluorescence implied that MoS 2 in the complex may mainly bind to tryptophan residues of BSA. The cyclic voltammograms indicated that the addition of BSA makes electron reduction of MoS 2 NFs more difficult than the corresponding free state. The results show that hydrophobic forces play a major role in the binding interaction between BSA and MoS 2 NFs. Graphical
研究领域:
材料科学
·
生物化学
·
分析化学
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PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
C.H. Yang,Y.L. Ding,J. Qian
A novel carboxymethyl chitosan-functionalized magnetic-fluorescent nanocomposites were synthesized and applied for simultaneous determination and removal of Hg 2+ . The resulting composites possessed strong paramagnetic effect and photoluminescence (PL) property measured at room temperature in the size range from 150 to 175 nm. The fluorescence of the resulting nanosensor could be effectively quenched by Hg 2+ ions. Under optimal conditions, the quenched fluorescence effect of Hg 2+ on the fluorescence of nanosensor found to be concentration dependent in the concentration range of 3 × 10 −7 –5 × 10 −6 mol/L. The detection limit of Hg 2+ was 9.1 × 10 −8 mol/L (n = 11). The influence of other coexisting ions on the fluorescence intensity of MFNPs nanosensor was also researched and coexisting ions displayed low interference effect response in detecting of Hg 2+ ions. The quenching mechanism was also considered and the result was proved as a static quenching process. In addition to the significant selectivity and sensitivity performance of nanocomposites sensor, it also has a excellent magnetic separation feature which would effectively avoid the secondary pollution.
研究领域:
环境科学
·
分析化学
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DOI
高影响因子
Analytical Methods
·
2024
·
IF 2.7
Changchang Chen,Yuqing Yang,Chenyang Ji,Yasi Shui,Xiaoyan Jiang,Renyong Liu,Chenggen Xie,Lijuan Chen
Herein, blue luminescent fluorescent poly(tannic acid) nanoparticles (FPTA NPs) were fabricated through chemical degradation of poly(tannic acid) large particles using H2O2, and the obtained FPTA NPs exhibited excellent water dispersibility, great fluorescence stability, and relatively high quantum yield. More importantly, based on the dynamic quenching and chelation enhanced quenching effect between FPTA NPs and bismuth ions (Bi3+), a fluorescence method for the rapid identification and detection of Bi3+ was developed. With the increase of Bi3+, the fluorescence of FPTA NPs could be quenched gradually; the linear range was 0.2–80 μM, R2 was 0.997, the detection limit was 13.54 nM, and the response time was as short as 10 s. The FPTA NP based nanoprobe was successfully applied for the determination of Bi3+ in water samples, and the recovery rate ranged from 98.18% to 105.89%, with a relative standard deviation of less than 3.48%, thereby confirming the feasibility of using FPTA NPs for detecting Bi3+ in real water samples.
研究领域:
分析化学
·
环境科学
·
材料科学
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DOI
PubMed
高影响因子
CHEMICAL PHYSICS
·
2021
·
IF 2.348
Deying Meng,Huangmei Zhou,Jianhua Xu,Sanjun Zhang
Salicylic acid and its monohydroxy substituted derivatives are usually used as food additives . They can interact with bovine serum albumin (BSA) through π-π stacking, the monohydroxy substitutions can hinder the interactions through steric effects . In this paper, we systematically studied the interactions between BSA and salicylic acid and its monohydroxy substituted derivatives under simulative physiological conditions by diverse spectroscopic methods and molecular docking studies. The spectroscopic studies showed that the intrinsic fluorescence of BSA could be quenched by salicylic acid and its derivatives. The quenching mechanism is a combination of static and dynamic quenching. Furthermore, the molecular docking simulation revealed the binding sites (near the Trp-213 in the BSA) and the distance (2.1 nm, 2.9 nm, 2.0 nm, 2.7 nm and 3.3 nm, respectively) between ligand and protein, which is in good agreement with the calculated results of the energy transfer process . Our research may provide guidance for understanding the interactions between serum albumin and salicylic acid food additives.
研究领域:
药学化学
·
生物化学
·
分子生物学
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DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2021
·
IF 10.618
Mingliang Mei,Lixuan Mu,Sen Liang,Yuan Wang,Guangwei She,Wensheng Shi
The aptasensor , developed from the aptamer, has aroused wide concern in recent years owing to its high sensitivity and specificity. However, the quenching unit involved in the most of the aptasensors is indispensable to the fabrication of an aptasensor, which would undoubtedly increase the complexity of the device. In this study, a facile strategy was developed for construction of the quencher-free aptasensors, in which the quenching units can be omitted, and only an aptamer strand and a fluorophore are necessary. Distinguishable from the configuration of the traditional ones, the aptasensors developed in this work rationally employed the intrinsic quenching abilities of the analytes to directly regulate the fluorescence of the fluorophore. Furthermore, the aptamer strand as a discriminatory unit efficiently captured the corresponding analytes to around the fluorophores. As a result, the fluorescence of the aptasensor can be significantly sensitive to the analytes. The generality of the current design is evidenced by the successful fabrication of seven quencher-free aptasensors for Cu 2+ , Ag + , Hg 2+ , ATP and dopamine through 6-FAM labeling aptamers of Cu 2+ , Ag + , Hg 2+ , ATP, dopamine, 5-TAMRA and ROX labeling aptamers of Cu 2+ . Present strategy endows an aptasensor with a simple structure, high selectivity and fine sensitivity. The configuration of the quencher-free aptasensors fabricated in this work can be readily utilized for more aptasensors.
研究领域:
分析化学
·
生物传感器
·
分子生物学
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PubMed
高影响因子
LUMINESCENCE
·
2013
·Vol. 29
·期 1
·79-86
·
IF 1.273
Li Shuai,Zhi Chen,Peng Fei,Qiang Wang,Tianming Yang
The interaction of trypsin with tetramethylpyrazine (TMP) and ferulic acid (FA) was studied using fluorescence, synchronous fluorescence, UV–vis absorption, circular dichroism (CD) and three-dimensional (3D) fluorescence spectra techniques. Using fluorescence quenching calculations, the bimolecular quenching constant ( k q ), apparent quenching constant ( K SV ), effective binding constant ( K a ) and binding site number ( n ) were obtained. The distance r between donor and acceptor was found to be 2.049 and 1.281 nm for TMP–trypsin and FA–trypsin complexes. TMP and FA can quench the fluorescence intensity of trypsin by a static quenching procedure. Thermodynamic parameters calculated on the basis of different temperatures revealed that the binding of trypsin to TMP/FA mainly depended on van der Waals' forces and hydrogen bonds. The effect of TMP and FA on the conformation of trypsin was analyzed using synchronous fluorescence, CD, 3D fluorescence spectra and molecular docking studies. Copyright © 2013 John Wiley & Sons, Ltd.
研究领域:
生物化学
·
分子生物学
·
光谱学
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DOI
PubMed
高影响因子
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