MOLECULES
·
2016
·Vol. 21
·期 12
·1642
·
IF 2.465
Yuzhen Zhao,Kexuan Li,Zemin He,Yongming Zhang,Yang Zhao,Haiquan Zhang,Zongcheng Miao
Perylene diimide derivatives were used as probes to investigate the effect of the molecular structures on the fluorescence quenching mechanism in a perylene diimide/graphene oxide system. The electrons transferred from the excited state of dyes to the conductive band of graphene oxide with different concentrations were determined by fluorescence spectra. The results indicated that the quenching efficiency of perylene diimides by graphene oxide was not only dependent on the difference between the lowest unoccupied molecular orbital level of dyes and the conduction band of the graphene oxide, but also mainly on the difference in the molecular structures.Keywords:electron transfer;perylene diimide dyes;fluorescence quenching mechanism;graphite oxide
研究领域:
化学
·
材料科学
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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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DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2021
·
IF 4.098
Guowen Zhang,Na Li,Ying Zhang,Junhui Pan,Deming Gong
4−Octylphenol (OP) is an environmental estrogen that can enter organisms through the food chain and cause various toxic effects. Here, the interaction between OP and human serum albumin (HSA) was explored through multipectral, molecular docking and dynamics simulation. The results showed that OP and HSA formed a ground state complex through a static quenching mechanism, and the interaction was spontaneously driven by hydrogen bonds and hydrophobic interaction forces. The binding constant at different temperatures was measured to be on the order of 10 5 L mol −1 . Site competition experiments suggested that OP interacted with amino acid residues Lys195, Cy245 and Cys246 located at the Sudlow site I of HSA, resulting in a more stretched protein peptide. The presence of OP increased the surface hydrophobicity of HSA, and reduced the content of α-helix in HSA by 3.4%. FT−IR spectra showed that OP interacted with the C=O and C-H groups of the polypeptide backbone. Molecular docking demonstrated that OP mainly bound to Site I of HSA and hydrogen bonds participated in the interaction. In addition, molecular dynamics simulations further explored the stability and dynamic behavior of the OP−HSA complex through RMSD, RMSF, SASA and Rg.
研究领域:
生物化学
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环境科学
·
分子生物学
✓ 已验证
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
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环境科学
·
生物医学
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产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2021
·
IF 4.464
Xia Qiu,Ling Wang,Yinggui Zhu
A novel electrochemiluminescence (ECL) system consisting of Eosin B (EB) and K 2 S 2 O 8 was studied and found to generate ECL following the oxidation or reduction of Eosin B and K 2 S 2 O 8 . The type of buffer solution, type of co-reactant, pH value, and K 2 S 2 O 8 concentration were optimized through experiments to make the reaction system reach the best value. In addition, we found that Cr 3+ has a great quenching effect on the EB reaction system. Through the comparison of ECL and CV under different conditions, DPV curve, UV spectrum and ECL spectrum experiments, we focused on the quenching mechanism of Cr 3+ on the system and made reasonable guesses. This method demonstrates the potential application value of ECL in the field of environmental monitoring and reveals the potential value of organic molecular ECL luminophores.
研究领域:
分析化学
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环境科学
·
电化学
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DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2023
·
IF 4.4
Tiantian Long,Zhongyang Hu,Ziyun Gao,Hongmei Luo,Hongchen Li,Yi Chen,Lei Liu,Dong Xu
Monitoring hypochlorite levels in water is of great importance because of its high toxicity and wide applications as water disinfectants. In this manuscript, carbon dot (CD) was electrochemically prepared by using dopamine and epigallocatechin gallate (molar ratio 1:1) as the carbon source for efficient hypochlorite determination. By electrolyzing the solution at 10 V for 12 min with PBS as an electrolyte, dopamine would react with epigallocatechin at the anode, and through polymerization, dehydration, and carbonization, strong blue-fluorescent CDs were obtained. CDs were characterized by UV–Vis spectroscopy, fluorescence spectroscopy, high-resolution transmission electron microscopy, FT-IR, etc. These CDs have an excitation wavelength at 372 nm and an emission wavelength at 462 nm, owing an average particle size of 5.5 nm. The presence of hypochlorites can quench the fluorescence of CDs, and its reduction in intensity is linear with hypochlorite concentration over the range of 0.5–50 μM, ΔF/F 0 = 0.0056 + 0.0194C ClO − , R 2 =0.997. The detection limit achieved 0.23 μM (S/N = 3). The mechanism for fluorescence quenching is via a dynamic process. Different from many other fluorescence methods based on the strong oxidizing ability of hypochlorites, our method shows strong selectivity toward hypochlorites over other oxidizing agents such as H 2 O 2 . The assay was validated by the detection of hypochlorites in water samples, with recoveries between 98.2% and 104.3%.
研究领域:
分析化学
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环境科学
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产品关联
DOI
PubMed
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2019
·Vol. 411
·期 27
·7165-7175
·
IF 3.286
Zhang Meng Yuan,Huang Ren Feng,Ma Xiao Guo,Guo Li Hui,Wang Ying,Fan Yin Ming
A new fluorescence sensor (QDs-IIP), based on ion-imprinted polymers (IIP) as recognition element and Mn-doped ZnS quantum dots (QDs) as fluorophore, was synthesized for the selective and sensitive determination of hexavalent chromium (Cr(VI)) ions. The QD was first coated by SiO 2 layer, and then modified with Cr(VI)-imprinted polymer. Several parameters affecting fluorescence intensity such as tetraethylorthosilicate (TEOS) volume, ZnS:Mn@SiO 2 amount, and radiation time were investigated and optimized. The QDs-IIP was characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), transmission electron microscope (TEM), and scanning electron microscope (SEM). Furthermore, the fluorescence quenching mechanism was investigated by using UV-VIS and fluorescence spectrophotometer, and it was found that internal filtration effect was the main fluorescence quenching mechanism. The relative fluorescence intensity (F 0 /F) increased linearly with the increase of Cr(VI) concentration in the range of 20 μg L −1 –1.0 mg L −1 . The QDs-IIP sensor showed high recognition selectivity for Cr(VI) in comparison with the QDs-NIP sensor with an imprinting factor (IF) of 2.53, and it could be reused 5 times. In addition, an analytical method of Cr(VI) based on the QDs-IIP sensor was established with a limit of detection of 5.48 μg L −1 , and was then applied to actual water samples with satisfactory results. Therefore, QDs-IIP can be deemed as a practicable fluorescent sensor for trace Cr(VI) detection.
Graphical abstract
研究领域:
分析化学
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环境科学
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DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2023
·
IF 4.8
Xuezhi Sun,Yunfan Qiao,Min Zhang,Yongzhe Cheng,Fanghong Ning,Hongyang Zhang,Ping Hu
The problem of antibiotic residues is very serious and is harmful to the ecological environment and the human body. We have developed a method for the rapid detection of antibiotics in water samples. Firstly, we prepared a fluorescent material (TPE@CLMOF) with cyclodextrin cross-linked MOF (CLMOF) and tetraphenylethylene (TPE) using a simple way. Due to diphenyl carbonate cross-linking, the fluorescent MOF can glow stably in water. Compared with TPE (40.1%), the absolute quantum yield of TPE@CLMOF increases to 63.2%. The fluorescence of TPE@CLMOF can be selectively quenched by Nitrofurans (NFs) and Tetracyclines (TCs) antibiotics in water. The detection limits of nitrofurazone, nitrofurantoin and chlortetracycline are 0.11, 0.13 and 0.16 μM, respectively. We have studied the adsorption of nitrofurazone, nitrofurantoin and chlortetracycline in TPE@CLMOF and the Langmuir adsorption model and pseudo-second-order kinetic model were established. The maximum adsorption capacity is 223, 209 and 185 mg g −1 , respectively. We also proposed a dual quenching mechanism of electron transfer and internal filtration effect, which is verified by quantum chemical calculations and experiments. Finally, the TPE@CLMOF was successfully used as a fluorescent sensor for the determination of antibiotic spiked honey samples.
研究领域:
环境科学
·
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Nano Express
·
2020
·Vol. 1
·期 3
·030006
·
IF 0
Farooq Ahmad,Tahir Muhmood,Asif Mahmood
Nanoparticles (NPs) are extensively being used in state-of-the-art nano-based therapies, modern electronics, and consumer products, so can be released into the environment with enhancement interaction with humans. Hence, the exposures to these multifunctional NPs lead to changes in protein structure and functionality, raising serious health issues. This study thoroughly investigated the interaction and adsorption of catalase (CAT) with HfO2-NPs by circular dichroism (CD), Fourier transform infrared (FTIR), absorption, and fluorescence spectroscopic techniques. The results indicate that HfO2 NPs cause fluorescence quenching in CAT by a static quenching mechanism. The negative values of Vant Hoff thermodynamic expressions (ΔHo, ΔSo, and ΔGo) corroborate the spontaneity and exothermic nature of static quenching driven by van der Waals forces and hydrogen bonding. Also, FTIR, UV-CD, and UV–visible spectroscopy techniques confirmed that HfO2 NPs binding could induce microenvironment perturbations leading to secondary and tertiary conformation changes in CAT. Furthermore, synchronous fluorescence spectroscopy confirmed the significant changes in the microenvironment around tryptophan (Trp) residue caused by HfO2 NPs. The time depending denaturing of CAT biochemistry through HfO2-NPs was investigated by assaying catalase activity elucidates the potential toxic action of HfO2-NPs at the macromolecular level. Briefly, this provides an empathetic knowledge of the nanotoxicity and likely health effects of HfO2 NPs exposure.
研究领域:
生物化学
·
纳米毒理学
·
环境科学
✓ 已验证
DOI
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 43
·期 21
·8363-8369
·
IF 3.069
Xiaoying Zhang,Xiaoli Kang,Wen Cui,Qing Zhang,Zhou Zheng,Xudong Cui
Two europium(III)-based metal–organic frameworks (MOFs) (Eu-BDC and Eu-BTC) have been synthesized by a solvothermal method with high sensitivity. It was found that the sensitivity of both Eu-BDC (0.065 vol%), which consists of flower-like microcrystals constructed by abundant nanoparticles, and Eu-BTC (0.06 vol%), which comprises nanolayer bunches, is below the occupational exposure limit of acetone (0.075 vol%) stipulated by the American Conference of Governmental Industrial Hygienists. In addition, Eu-BDC and Eu-BTC have good chemical stability and are promising for detection of acetone content in the environment. The fluorescence-quenching mechanism for Eu-BDC and Eu-BTC may be the fluorescence inner filter effect. Furthermore, the morphology of Eu-MOFs, that is, the specific surface area and pore size distribution, may be one of the factors affecting the fluorescence intensity and sensitivity of Eu-MOFs to acetone.
研究领域:
材料科学
·
分析化学
·
环境科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）