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Journal of Fluorescence

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https://www.readbyqxmd.com/read/28321598/preparation-of-highly-biocompatible-znse-quantum-dots-using-a-new-source-of-acetyl-cysteine-as-capping-agent
#1
Ehsan Soheyli, Reza Sahraei, Gholamreza Nabiyouni
In this paper, we describe a facile method for preparation of ZnSe quantum dots (QDs) using an inexpensive and biocompatible source of acetyl cysteine in aqueous media. The structural properties of the ZnSe QDs have been characterized using XRD, FT-IR, and TEM techniques. The optical properties of the as-prepared QDs were found to be size-dependent, due to the strong confinement regime at relatively low refluxing time. Effect of solution pH and refluxing temperature on absorption and emission characteristics of the ZnSe QDs was studied...
March 20, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28303488/photophysics-of-dihydroquinazolinone-derivatives-experimental-and-theoretical-studies
#2
Mehboobali Pannipara, Abdullah G Al-Sehemi, Abul Kalam, T N Mohammed Musthafa
Herein, we report the synthesis of two dihydroquinazolinone derivative 2-(2-Hydroxy-naphthalen-1-yl)-2, 3-dihydro-1H-quinazolin-4-one (1) and 2-(3-Methyl-thiophen-2-yl)-2,3-dihydro-1H-quinazolin-4-one (2) by using 2-aminobenzamide, 2-hydroxybenzaldehyde and 3-methyl thiophene-2-carboxaldehyde. The synthesized compounds were characterized by 1H NMR, 13C NMR, FT-IR and its spectral, photophysical, intramolecular charge transfer characteristics were studied by absorption and emission spectroscopy. The synthesized compound exhibits significant changes in their photophysical properties depending on the solvent polarity...
March 17, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28299532/coumarin-based-fluorescent-probe-for-colorimetric-detection-of-fe-3-and-fluorescence-turn-on-off-response-of-zn-2-and-cu-2
#3
Nayan Roy, Abhijit Dutta, Paritosh Mondal, Pradip C Paul, T Sanjoy Singh
A new coumarin based Schiff-base chemosensor-(E)-7-(((8-hydroxyquinolin-2-yl)methylene) amino)-4-methyl-2H-chromen-2-one (H 11 L) was synthesized and evaluated as a colorimetric sensor for Fe(3+) and fluorescence "turn on-off" response of Zn(2+) and Cu(2+) using absorption and fluorescence spectroscopy. Upon treatment with Fe(3+) and Zn(2+), the absorption intensity as well as the fluorescence emission intensity increases drastically compared to other common alkali, alkaline earth and transition metal ions, with a distinct color change which provide naked eye detection...
March 15, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28299531/formation-of-pentosidine-cross-linking-in-myoglobin-by-glyoxal-detection-of-fluorescent-advanced-glycation-end-product
#4
Sauradipta Banerjee
Glyoxal, a reactive α-oxoaldehyde, increases in diabetic condition and reacts with proteins to form advanced glycation end products (AGEs) following Maillard-like reaction. Considering the significance of protein modification by glyoxal-derived AGEs, we investigated the in vitro effect of glyoxal (200 μM) on the monomeric heme protein myoglobin (Mb) (100 μM) after incubation for one week at 25 °C. Glyoxal-treated Mb exhibited increased absorbance around the Soret region, decreased α-helicity and thermal stability compared to control Mb...
March 15, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28293816/triphenylbenzene-sensor-for-selective-detection-of-picric-acid
#5
S Nagendran, Pratap Vishnoi, Ramaswamy Murugavel
A C 3-symmetric triphenylbenzene based photoluminescent compound, 1,3,5-tris(4'-(N-methylamino)phenyl) benzene ([NHMe]3TAPB), has been synthesized by mono-N-methylation of 1,3,5-tris(4'-aminophenyl) benzene (TAPB) and structurally characterized. [NHMe]3TAPB acts as a selective fluorescent sensor for picric acid (PA) with a detection limit as low as 2.25 ppm at a signal to noise ratio of 3. Other related analytes (i.e. TNT, DNT and DNB) show very little effect on the fluorescence intensity of [NHMe]3TAPB. The selectivity is triggered by proton transfer from picric acid to the fluorophore and ground-state complex formation between the protonated fluorophore and picrate anion through hydrogen bonding interactions...
March 14, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28293815/selectivity-improvement-for-spectrofluorimetric-determination-of-oseltamivir-phosphate-in-human-plasma-and-in-the-presence-of-its-degradation-product
#6
Mahmoud A Omar, Sayed M Derayea, Islam M Mostafa
A simple and sensitive spectrofluorimetric method has been developed and validated for determination of oseltamivir phosphate (OSP). The proposed method is based on condensation reaction of the primary amino group of OSP with ninhydrin and phenylacetaldehyde in buffered medium (pH 6.5). The formed yellow fluorescent product exhibits excitation and emission maxima at 390 and 460 nm, respectively. The selectivity improvement of our proposed method is based on the water insolubility of the oseltamivir carboxylic acid (OSC) the active metabolite of OSP, which contains the same primary amino group as OSP but cannot, condensed with ninhydrin and phenylacetaldehyde reagents...
March 14, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28289996/relative-study-of-luminescent-properties-with-judd-ofelt-characterization-in-trivalent-europium-complexes-comprising-ethyl-4-fluorobenzoyl-acetate
#7
Rekha Devi, Sangeeta Chahar, S P Khatkar, V B Taxak, Priti Boora
Five new europium(III) complexes Eu(p-EFBA)3.(H2O)2 (C1), Eu(p-EFBA)3.neo (C2), Eu(p-EFBA)3.batho (C3), Eu(p-EFBA)3.phen (C4), Eu(p-EFBA)3.bipy (C5) have been synthesized by using ethyl-(4-fluorobenzoyl) acetate (p-EFBA) as β-ketoester ligand and neocuproine (neo), bathophenanthroline (batho), 1,10-phenanthroline (phen) and 2,2-bipyridyl (bipy) as ancillary ligands. The synthesized complexes C1-C5 were characterized by elemental analysis, nuclear magnetic resonance spectroscopy ((1)H-NMR), infrared (IR) spectroscopy, thermogravimetric analysis (TG/DTG), UV-visible and photoluminescence (PL) spectroscopy...
March 13, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28289995/a-highly-selective-and-sensitive-fluorescent-turn-on-probe-for-al-3-based-on-naphthalimide-schiff-base
#8
Hongping Peng, Kesheng Shen, Shanshan Mao, Xinkui Shi, Yuling Xu, Stephen Opeyemi Aderinto, Huilu Wu
A simple and highly selective aluminium ion fluorescent probe (N-n-butyl-4-[3,3'-((2-aminoethyl)azanediyl)bis(N'-(2-hydroxy-3-methoxybenzylidene)-propanehydrazide)]-1,8-naphthalimide) (P-1) employing 1,8-naphthalimide as the fluorophore group and Schiff base as the recognition group has been successfully synthesized and systemically characterized. The structure of probe P-1 has been established by single crystal X-ray. The photophysical properties of probe P-1 revealed that the values of the fluorescence quantum yield are higher in non-polar solvents than in polar solvents...
March 13, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28289994/determination-of-rhodamine-b-in-food-samples-by-fe3o4-ionic-liquids-%C3%AE-cyclodextrin-cross-linked-polymer-solid-phase-extraction-coupled-with-fluorescence-spectrophotometry
#9
Almojtaba AbdAlkhalig Ahmed Bakheet, Xia Shi Zhu
Fe3O4@Ionic liquids β-cyclodextrin polymer(Fe3O4@ mono-6- deoxy-6- (1-ethyl- imidazolium)-β-cyclodextrin iodide polymer, ILs-β-CDCP) was prepared. A novel method based on Fe3O4@ILs-β-CDCP solid phase extraction coupled with fluorescence spectrophotometry for Rhodamine B (RhB) determination, was investigated. Results were shown that RhB was adsorbed on Fe3O4@ILs-β-CDCP and eluted with sodium dodecyl sulfate (SDS) (1.0%) rapidly. Different parameters, such as pH, adsorption time and volume, eluent volume and time were studied...
March 13, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28286913/laser-performance-of-some-oxazole-laser-dyes-in-restricted-matrices
#10
Mahmoud A S Sakr, Sayed A Abdel Gawad, Maram T H Abou Kana, El-Zeiny M Ebeid
This article reports the optical properties such as absorption profile, molar absorptivity, fluorescence profile and photo-physical parameters such as dipole moment, oscillator strength, fluorescence quantum yields, fluorescence lifetimes, laser performance and finally photostability of 2,5-Bis(5-tert-butyl-benzoxazol-2-yl)thiophene (BBOT),1,4-Bis(5-phenyl-2-oxazolyl)benzene (POPOB), 5-diphenyel-oxazole (PPO) laser dyes in different restricted hosts. (BBOT), (POPOB) and (PPO) are embedded in transparent silica-based nanoporous sol-gel glass and copolymer matrix of methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA)...
March 13, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28283901/synthesis-x-ray-and-fluorescence-characteristics-of-pyrimido-5-4-e-thiazolo-3-2-a-pyrimidine-as-a-novel-heterocyclic-system
#11
Zahra Ebrahimpour, Mehdi Bakavoli, Ali Shiri, Seyed Mohammad Seyedi, Tayebe Asghari, Joel T Mague
Derivatives of a new heterocyclic system, pyrimido[5,4-e]thiazolo[3,2-a]pyrimidine 3, were prepared by sequential treatment of ethyl 4-chloro-2-(methylthio)pyrimidine-5-carboxylate 1 with 4,5-dihydrothiazol-2-amine 2 and various secondary amines. Single crystal X-ray analysis confirmed the structure of the regioisomer 3. The photophysical characterization of these new compounds was performed by UV/VIS absorption and fluorescence emission spectroscopy. Out of six derivatives studied, only four products 4a-d showed relatively strong fluorescence intensity...
March 10, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28283900/specific-fluorescence-probe-for-direct-recognition-of-dimethoate-using-molecularly-imprinting-polymer-on-zno-quantum-dots
#12
Behrouz Vahid
ZnO quantum dots (QDs) based molecularly imprinting polymer (MIP)-coated composite was described for specific detection of the dimethoate (DM) as a template. The MIP was synthesized by simple self-assembly of 3-aminopropyl triethoxysilane (APTES) monomers and tetraethyl ortho-silicate as cross linking agent in the presence of template molecules. The used imprinting course can improve the tendency of the prepared QDs toward the DM template molecules. The MIP-coated ZnO QDs showed a strong fluorescence emission which undergoes a quenching effect in the presence of DM...
March 10, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28283899/liposomal-co-encapsulation-of-two-novel-europium-complexes-and-doxorubicin-fluorescence-study
#13
Valeriya M Trusova, Todor Deligeorgiev, Galyna Gorbenko
The present study was undertaken to design the novel liposomal drug formulation containing doxorubicin and europium coordination complexes. It was shown that co-encapsulation of the drugs facilitates the partitioning and permeation of lanthanides into the lipid bilayer. The obtained results suggest that new drug platform may have potential application in the design of novel antitumor agents.
March 10, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28283898/a-new-fluorescent-turn-off-coumarin-based-chemosensor-synthesis-structure-and-cu-selective-fluorescent-sensing-in-water-samples
#14
Kaan Karaoglu, Fatih Yilmaz, Emre Menteşe
We report the synthesis and characterization two coumarin-based fluorescence probes, N'-{[7-(diethylamino)-2-oxo-2H-chromen-3-yl]carbonyl}pyridine-3-carbohydrazide (3) and N'-benzoyl-7-(diethylamino)-2-oxo-2H-chromene-3-carbohydrazide (4), proposed as a novel fluorescent chemosensor. The two probes designed showed an instant turn-off fluorescence response to Cu(2+) over other metal ions in ethanol-water mixture based on intramolecular charge transfer (ICT). It was found that pyridine-analogue coumarin is highly selective and sensitive sensor for Cu(2+)...
March 10, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28265832/microwave-assisted-synthesis-characterisation-and-fluorescence-studies-of-some-transition-metal-complexes-with-a-luminol-derivative
#15
R Aswathy, K Mohanan
A novel heterocyclic luminol derivative was synthesized by coupling diazotized 5-aminophthalhydrazide with 2-naphthol. This compound viz., Phthalhydrazide-5-azo-2-naphthol is versatile in forming stable metal complexes with cobalt(II), nickel(II), copper(II) and zinc(II) ions under microwave assisted solvent free conditions. The ligand and the metal complexes were characterized on the basis of elemental analyses, molar conductance, magnetic susceptibility measurements, UV-Visible, IR, (1)H NMR, and ESR spectral studies wherever possible and applicable...
March 7, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28251418/comparison-between-two-linear-supervised-learning-machines-methods-with-principle-component-based-methods-for-the-spectrofluorimetric-determination-of-agomelatine-and-its-degradants
#16
Mahmoud M Elkhoudary, Ibrahim A Naguib, Randa A Abdel Salam, Ghada M Hadad
Four accurate, sensitive and reliable stability indicating chemometric methods were developed for the quantitative determination of Agomelatine (AGM) whether in pure form or in pharmaceutical formulations. Two supervised learning machines' methods; linear artificial neural networks (PC-linANN) preceded by principle component analysis and linear support vector regression (linSVR), were compared with two principle component based methods; principle component regression (PCR) as well as partial least squares (PLS) for the spectrofluorimetric determination of AGM and its degradants...
March 1, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28251417/synthesis-of-novel-thiazole-based-carbaldehyde-as-potential-sensor-for-fluoride-anion-and-their-spectroscopic-properties
#17
Rajratna P Tayade, Nagaiyan Sekar
A novel thiazole based carbaldehyde bearing benzimidazole fluorophore as the receptor unit for F (-) anion was prepared by multi steps synthesis. Density functional theory was used to understand the structural and electronic properties the receptor. The anion sensing activities of receptor 4 were studied for various anions in acetonitrile solvent. The receptor showed fluorescence enhancement in the presence of fluoride anion due to intramolecular charge transfer (ICT) mechanism. No significant changes were observed upon addition of less basic anions such as OAc(-), Cl(-), Br(-), I(-), HSO4(-)...
March 1, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28247070/synthesis-spectral-characterization-sem-antimicrobial-antioxidative-activity-evaluation-dna-binding-and-dna-cleavage-investigation-of-transition-metal-ii-complexes-derived-from-a-tetradentate-schiff-base-bearing-thiophene-moiety
#18
Ayman A Abdel Aziz, Sabry H Seda
A novel series of Co(II), Ni(II), Cu(II) and Zn(II) mononuclear complexes have been synthesized involving a potentially tetradentate Schiff base ligand, which was obtained by condensation of 2-aminophenol with 2,5-thiophene-dicarboxaldehyde. The complexes were synthesized via reflux reaction of methanolic solution of the appropriate Schiff base ligand with one equivalent of corresponding metal acetate salt. Based on different techniques including micro analysis, FT-IR, NMR, UV-Vis, ESR, ESI-mass and conductivity measurements, four-coordinated geometry was assigned for all complexes...
March 1, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28247069/spectroscopic-studies-of-fluorescence-effects-in-bioactive-4-5-heptyl-1-3-4-thiadiazol-2-yl-benzene-1-3-diol-and-4-5-methyl-1-3-4-thiadiazol-2-yl-benzene-1-3-diol-molecules-induced-by-ph-changes-in-aqueous-solutions
#19
Arkadiusz Matwijczuk, Dariusz Kluczyk, Andrzej Górecki, Andrzej Niewiadomy, Mariusz Gagoś
This paper presents the results of stationary fluorescence spectroscopy and time-resolved spectroscopy analyses of two 1,3,4-thiadiazole analogues, i.e. 4-(5-methyl-1,3,4-thiadiazol-2-yl)benzene-1,3-diol (C1) and 4-(5-heptyl-1,3,4-thiadiazol-2-yl)benzene-1,3-diol (C7) in an aqueous medium containing different concentrations of hydrogen ions. An interesting dual florescence effect was observed when both compounds were dissolved in aqueous solutions at pH below 7 for C1 and 7.5 for C7. In turn, for C1 and C7 dissolved in water at pH higher than the physiological value (mentioned above), single fluorescence was only noted...
March 1, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28233249/highly-sensitive-and-selective-turn-on-fluorescent-probe-for-hg-2-based-on-rhodamine-6g-thiourea-conjugate
#20
Ying-Zi Ding, Hui-Li Gong, Kun-Peng Wang
An easily available novel fluorescent probe based on rhodamine 6G-thiourea conjugate (RGTU) has been synthesized. Upon mixed with Hg(2+) in CH3CN-H2O (1:9, v/v), the dramatic enhancement of fluorescence intensity as well as the color change of the solution were observed. The presence of common coexisting alkali, alkaline earth, and transition metal ions showed small or no interference with the detection of Hg(2+). The Job's plot and (1)H NMR spectra indicated that Hg(2+) induced spirolactam open to form 1:1 complex between RGTU and Hg(2+)...
February 23, 2017: Journal of Fluorescence
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