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https://www.readbyqxmd.com/read/28651241/al-based-metal-organic-gels-for-selective-fluorescence-recognition-of-hydroxyl-nitro-aromatic-compounds
#1
Mao Xia Guo, Liu Yang, Zhong Wei Jiang, Zhe Wei Peng, Yuan Fang Li
The novel class of luminescent Al(3+)-based metal-organic gels (Al-MOGs) have been developed by mix 4-[2,2':6',2″-terpyridine]-4'-ylbenzoic acid (Hcptpy) with Al(3+) under mild condition. The as-prepared Al-MOGs have not only multiple stimuli-responsive properties, but selective recognition of hydroxyl nitro aromatic compounds, which can quench the fluorescence of the Al-MOGs, while other nitro aromatic analogues without hydroxyl substitutes cannot. The fluorescence of Al-MOGs at 467nm was seriously quenched by picric acid (PA) whose lowest unoccupied molecular orbital (LUMO) energy levels are lower than those of three other hydroxyl nitro aromatic compounds including 4-nitrophenol (4-NP), 3,5-dinitrosalicylic acid (3,5-DNTSA) and 2,4-dinitrophenol (2,4-DNP)...
May 27, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28650635/ternary-interactions-and-energy-transfer-between-fluorescein-isothiocyanate-adenosine-triphosphate-and-graphene-oxide-nanocarriers
#2
Katarzyna Ratajczak, Magdalena Stobiecka
The interactions of fluorescent probes and biomolecules with nanocarriers are of key importance to the emerging targeted drug delivery systems. Graphene oxide nanosheets (GONs) as the nanocarriers offer biocompatibility and robust drug binding capacity. The interactions of GONs with fluorophores lead to strong fluorescence quenching, which may interfere with fluorescence bioimaging and biodetection. Herein, we report on the interactions and energy transfers in a model ternary system: GONs-FITC-ATP, where FITC is a model fluorophore (fluorescein isothiocyanate) and ATP is a common biomolecule (adenosine-5'-triphosphate)...
June 26, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28650607/self-diffusion-driven-ultrafast-detection-of-ppm-level-nitro-aromatic-pollutants-in-aqueous-media-using-a-hydrophilic-fluorescent-paper-sensor
#3
Wei Lu, Jiawei Zhang, Youju Huang, Patrick Theato, Qing Huang, Tao Chen
Development of fluorescent film probes for toxic nitro aromatic compound pollutants (NACs) such as 2,4,6-trinitrotoluene (TNT) in real water samples implies broad applications in environmental and industrial safety control. Despite many recent advances, there are still some difficult challenges facing this area, e.g., the restricted sensitivity and long response time caused by hindered and slow diffusion of aqueous NACs samples inside a dense, solid film. Hence, we report herein a robust fluorescent paper sensor with improved sensing abilities, which is prepared by absorbing hydrophilic pyrene-functionalized polymer uniformly into cellulose-based filter papers...
June 26, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28650152/accelerated-reduction-of-bromate-in-frozen-solution
#4
Dae Wi Min, Wonyong Choi
Bromate is a common disinfection by-product formed during ozonation. Reducing bromate into bromide can remove this toxic pollutant, however, not many studies have been done for its environmental fate. In this work, we demonstrate a new transformation pathway that bromate can be efficiently reduced to bromide in frozen solution in the presence of organic reductants like humic substances (HS). The results showed that bromate in frozen solution could be removed by 30~40% in dark condition and 80~90% in irradiation condition (λ > 300 nm) in 24 h, while around 1% bromate was reduced in aqueous solution...
June 26, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28650022/interaction-and-inhibitory-influence-of-the-azo-dye-carmoisine-on-lysozyme-amyloid-fibrillogenesis
#5
Anirban Basu, Gopinatha Suresh Kumar
The binding of the common food colorant carmoisine and its inhibitory effect on amyloid fibrillation in lysozyme have been investigated. Since humans are increasingly exposed to various food colorants like carmoisine, such studies are highly relevant. In the presence of lysozyme, the carmoisine absorption spectrum exhibited hypochromic changes. The intrinsic fluorescence of lysozyme was also quenched on interaction. Time-resolved fluorescence results suggested that the binding mechanism involved ground state complexation...
June 26, 2017: Molecular BioSystems
https://www.readbyqxmd.com/read/28649045/roles-of-phytoplankton-and-macrophyte-derived-dissolved-organic-matter-in-sulfamethazine-adsorption-on-goethite
#6
Leilei Bai, Chicheng Cao, Chunliu Wang, Changhui Wang, Hui Zhang, Helong Jiang
Phytoplankton-derived dissolved organic matter (PDOM) and macrophyte-derived dissolved organic matter (MDOM) exist ubiquitously in eutrophic freshwater lakes. To understand the heterogeneous roles of individual fluorescent DOM components in the adsorption of antibiotics onto sediment minerals, the adsorptive fractionation of DOM on goethite (α-FeOOH) and its interaction with sulfamethazine (SMT) were investigated using fluorescence excitation-emission matrix combined with parallel factor analysis (EEM-PARAFAC)...
June 22, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28649026/proximity-hybridization-regulated-electrogenerated-chemiluminescence-bioassay-of-%C3%AE-fetoprotein-via-target-induced-quenching-mechanism
#7
Hongfang Gao, Xiaofei Wang, Man Li, Honglan Qi, Qiang Gao, Chengxiao Zhang
A proximity hybridization-regulated electrogenerated chemiluminescence (PLA-ECL) bioassay was developed for the detection of α-fetoprotein (AFP) on basis of the sensitization of gold nanoparticles (AuNPs) and target-induced quenching mechanism. Ru(bpy)3(2+) was used as ECL signal while ferrocene (Fc) was used as ECL quencher. Ru(bpy)3(2+) was electrostatically adsorbed into the AuNPs/Nafion film prepared by casting the mixture of Nafion and AuNPs onto the surface of glassy carbon electrode (GCE) to form an ECL platform (Ru(bpy)3(2+)/AuNPs/Nafion/GCE), which displayed strong ECL emissions...
June 21, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28649022/a-portable-rgb-sensing-gadget-for-sensitive-detection-of-hg-2-using-cysteamine-capped-qds-as-fluorescence-probe
#8
Bin Chen, Jun Ma, Tong Yang, Lin Chen, Peng Fei Gao, Cheng Zhi Huang
A facile one-pot method was proposed to synthesis cysteamine capped CdTe QDs with a high quantum yield 30%. In the synthesis process, nitrogen protection, ultrasonic treatment, and light irradiation were unnecessary. Additionally, potassium tellurite was used instead of Te powder as Te source, avoiding of the time-consuming Te powder dissolution process. The prepared QDs were found to be Hg(2+) sensitive. The detection linear range for Hg(2+) was from 5 to 300nM, and the detection limit was calculated to be 1nM...
June 8, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28648863/two-phase-amorphous-amorphous-solid-drug-dispersion-with-enhanced-stability-solubility-and-bioavailability-resulting-from-ultrasonic-dispersion-of-an-immiscible-system
#9
Luz María Martínez, Marcelo Videa, Tania López Silva, Samuel Castro, Adolfo Caballero, Víctor J Lara-Díaz, Fabiola Castorena-Torres
Amorphization of active pharmaceutical ingredients (APIs) and the preparation of solid dispersions are strategies that can be synergized to improve the solubility of oral drugs. Immiscibility between an API and a carrier in the molten state that could be perceived as a problem in the preparation of solid dispersions, may actually introduce an advantage. In the present work, a two-phase amorphous-amorphous solid dispersion (AASD) was prepared by ultrasonicating a molten immiscible mixture of indomethacin (IND) and glucose (GLU) prior quenching...
June 22, 2017: European Journal of Pharmaceutics and Biopharmaceutics
https://www.readbyqxmd.com/read/28646629/mechanisms-of-inhibitory-effects-of-polycyclic-aromatic-hydrocarbons-in-the-photosynthetic-primary-processes-in-pea-leaves-and-thylakoid-preparations
#10
V D Kreslavski, M Brestic, S K Zharmukhamedov, V Yu Luybimov, A V Lankin, A Jajoo, S I Allakhverdiev
Inhibitory effects of Polycyclic aromatic hydrocarbons on plants is studied in pea leaves in order to elucidate the mechanisms of action of polycyclic aromatic hydrocarbons (PAHs) such as naphthalene (Naph) and phenanthrene (Phen) on activity of photosystem 2 (PS-2). The changes in different Chl fluorescence parameters were calculated on the basis of Chl fluorescence induction curves. Hydrogen peroxide content was measured in leaf homogenates by luminol-dependent chemiluminescence method. We demonstrated that due to PAH treatment, the total energy dissipation (DI0 /ABS) and amount of QB -non-reducing complexes of PS-2 significantly increased...
June 24, 2017: Plant Biology
https://www.readbyqxmd.com/read/28646298/an-on-off-on-fluorescent-probe-for-ascorbic-acid-based-on-cu-zncds-quantum-dots-and-%C3%AE-mno2-nanorods
#11
Hanbing Rao, Yao Gao, Hongwei Ge, Zhaoyi Zhang, Xin Liu, Yan Yang, Yaqin Liu, Wei Liu, Ping Zou, Yanying Wang, Xianxiang Wang, Hua He, Xianying Zeng
This work established a fluorescence approach for detecting ascorbic acid (AA) based on Cu-ZnCdS quantum dots (Cu-ZnCdS QDs) and α-MnO2 nanorods. Cu-ZnCdS QDs and α-MnO2 nanorods were characterized by high-resolution transmission electron microscopy (HRTEM), fluorescence spectroscopy, inductively coupled plasma optical emission spectroscopy (ICP-OES) and X-ray diffraction (XRD). In the presence of α-MnO2 nanorods, the fluorescence of Cu-ZnCdS QDs was greatly quenched through the inner filter effect (IFE)...
June 23, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28645163/variations-in-chloroplast-movement-and-chlorophyll-fluorescence-among-chloroplast-division-mutants-under-light-stress
#12
Siddhartha Dutta, Jeffrey A Cruz, Saif M Imran, Jin Chen, David M Kramer, Katherine W Osteryoung
Chloroplasts divide to maintain consistent size, shape, and number in leaf mesophyll cells. Altered expression of chloroplast division proteins in Arabidopsis results in abnormal chloroplast morphology. To better understand the influence of chloroplast morphology on chloroplast movement and photosynthesis, we compared the chloroplast photorelocation and photosynthetic responses of a series of Arabidopsis chloroplast division mutants with a wide variety of chloroplast phenotypes. Chloroplast movement was monitored by red light reflectance imaging of whole plants under increasing intensities of white light...
June 22, 2017: Journal of Experimental Botany
https://www.readbyqxmd.com/read/28645033/acetic-acid-assisted-fabrication-of-hierarchical-flower-like-bi2o3-for-photocatalytic-degradation-of-sulfamethoxazole-and-rhodamine-b-under-solar-irradiation
#13
Yueping Bao, Teik-Thye Lim, Ziyi Zhong, Rong Wang, Xiao Hu
With the assistance of acetic acid (CH3COOH), a novel 3D flower-like Bi2O3 was synthesized via hydrothermal process followed by calcination. For the first time, the role of CH3COOH as a capping agent in the formation of flower-like structure was investigated. The as-prepared flower-like Bi2O3 had a high activity on the degradation of sulfamethoxazole (SMX) under simulated solar light irradiation due to the narrow band gap of 2.69eV, high percentage of β-Bi2O3 as well as high intensity of polar facets (120) and (200)...
May 23, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28644960/improved-simulation-based-hr-ebsd-procedure-using-image-gradient-based-dic-techniques
#14
Jon Alkorta, Matthieu Marteleur, Pascal J Jacques
Conventional HR-EBSD is attracting much interest due to its ability of measuring relative crystal misorientations and microstresses with great accuracy. However, this technique needs the use of simulated patterns in order to get absolute values of crystal orientation and stresses and thus expand its use to intergranular analyses. Simulation-based approaches have shown many limitations due to the poor correlation with the real patterns specially when Bragg simulations are considered. This paper presents an improved algorithm based on gradient-based correlation techniques that makes simulation-based HR-EBSD possible...
June 14, 2017: Ultramicroscopy
https://www.readbyqxmd.com/read/28644628/stereoelectronics-of-the-hydrogen-bond-induced-fluorescence-quenching-of-3-aminofluorenones-with-alcohols
#15
Isaac G Alty, Christopher John Abelt
Two derivatives of 3-amino-9-fluorenone (1) bearing one (2) and two methyl (3) groups flanking carbonyl group are prepared. Comparison of their photophysical properties show that all suffer efficient radiationless deactivation in the presence of alcohols. Preferential solvation studies with mono alcohols reveal that a single H-bonding interaction quenches the excited states of 1 and 2, but not that of 3. In contrast, a single molecule of ethylene glycol quenches all three. These results are interpreted in a quenching mechanism similar to one proposed by Inoue and coworkers, but where an out-of-plane H-bond with the carbonyl group gives rise to an emissive species, while an in-plane H-bond results in quenching...
June 23, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28644503/the-first-re-i-organometallic-complex-with-an-organoimido-polyoxometalate-ligand
#16
Patricio Hermosilla-Ibáñez, Kerry Wrighton-Araneda, Gaspar Prado, Verónica Paredes-García, Nancy Pizarro, Andrés Vega, Diego Venegas-Yazigi
The spectroscopic, electrochemical and photophysical properties of the first Re(I) organometallic organoimido-polyoxometalate complex [n-Bu4N][Mo6O18NC6H4-CH2-N3C2H2-Re-phen(CO)3] compared with all fragments are reported. The UV-Vis spectra are analysed using experimental and theoretical tools. In contrast to the reported studies in the literature, our results show that a new more intense band is present in the spectra of the hybrid ligand obscuring the intra-polyanion charge transfer. The electrochemical results show that the strong acceptor character of the polyoxometalate fragment is quenched by the condensation of the phenyl-triazole molecule...
June 23, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28644497/novel-tunable-green-red-emitting-oxynitride-phosphors-co-activated-with-ce-3-tb-3-and-eu-3-photoluminescence-and-energy-transfer
#17
Jiansheng Huo, Langping Dong, Wei Lü, Baiqi Shao, Hongpeng You
A series of novel Ce(3+), Tb(3+) and Eu(3+) ion doped Y4SiAlO8N-based oxynitride phosphors were synthesized by the solid-state method and characterized by X-ray powder diffraction, scanning electron microscopy, photoluminescence, lifetimes and thermo-luminescence. The excitation of the Ce(3+)/Tb(3+) co-doped and Ce(3+)/Tb(3+)/Eu(3+) tri-doped phosphor with near-UV radiation results in strong linear Tb(3+) green and Eu(3+) red emission. The occurrence of Ce(3+)-Tb(3+) and Ce(3+)-Tb(3+)-Eu(3+) energy transfer processes is responsible for the bright green or red luminescence...
June 23, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28644391/molecular-structure-affinity-relationship-of-flavonoids-in-lotus-leaf-nelumbo-nucifera-gaertn-on-binding-to-human-serum-albumin-and-bovine-serum-albumin-by-spectroscopic-method
#18
Xiaosheng Tang, Ping Tang, Liangliang Liu
Lotus leaf has gained growing popularity as an ingredient in herbal formulations due to its various activities. As main functional components of lotus leaf, the difference in structure of flavonoids affected their binding properties and activities. In this paper, the existence of 11 flavonoids in lotus leaf extract was confirmed by High Performance Liquid Chromatography (HPLC) analysis and 11 flavonoids showed various contents in lotus leaf. The interactions between lotus leaf extract and two kinds of serum albumins (human serum albumin (HSA) and bovine serum albumin (BSA)) were investigated by spectroscopic methods...
June 23, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28644005/from-electrochemistry-to-electroluminescence-development-and-application-in-ratiometric-aptasensor-for-aflatoxin-b1
#19
Long Wu, Fan Ding, Wenmin Yin, Jing Ma, Biru Wang, Axiu Nie, Heyou Han
Aflatoxin B1 (AFB1), one of the most toxic chemical carcinogens, has been widely studied. It remains challenging to develop simple, accurate and sensitive analytical methods for the detection of AFB1 in food matrices. In this work, based on dual-signaling strategy, a ratiometric aptasensor was designed and verified for the accurate and sensitive detection of AFB1. The electrochemical method was first used as a model to verify the specific interaction between AFB1 and the aptamer, in which ferrocene (Fc) and methylene blue (MB) anchored DNA sequences were acted as dual signals...
June 23, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28643834/understanding-the-remarkable-luminescence-enhancement-via-sio2-coating-on-tio2-eu-3-nanofibers
#20
Meiqi Chang, Yanhua Song, Ye Sheng, Jie Chen, Haifeng Zou
TiO2:Eu(3+) nanofibers diameters can be tuned by changing the mixed solvent ratio are synthesized via the electrospinning technique. Concentration quenching phenomena and the relationship of the PL intensity ratio I((5)D0-(7)F2)/I((5)D0-(7)F1) with the Eu doping concentration are discussed. Notably, the luminescence intensity is enhanced by about 7.8 fold by coating SiO2 gel layer on the TiO2:Eu(3+) nanofibers, which is successfully performed via a sol-gel process followed by calcination. Furthermore, these fibers are characterized systematically via X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), Fourier transform infrared spectroscopy (FT-IR), and photoluminescence (PL) spectroscopy...
June 23, 2017: Physical Chemistry Chemical Physics: PCCP
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