scholarly journals Optical Response of Poly (1,4-Phenylene-1,2-Di (P-Phenoxyphenyl) Vinylene) Towards Oxygen Gas

2017 ◽  
Vol 21 (1) ◽  
pp. 25
Author(s):  
F.S Mehamod ◽  
R Daik ◽  
M Ahmad
Keyword(s):  
Melting Point ◽  
Fluorescence Quenching ◽  
Polymer Solution ◽  
Fluorescence Intensity ◽  
Response Curve ◽  
Fluorescence Spectra ◽  
Coupling Reaction ◽  
Point Measurement ◽  
Anhydrous Alcl3 ◽  
Oxygen Gas

This research involved the synthesis of poly (1,4-phenylene-1,2-di (p-phenoxyphenyl) vinylene), dpop-PDV from di (p-phenoxybenzoyl) benzene compound as the monomer. The potential of the produced polymer as sensing reagent for O2 detection based on fluorescence quenching was studied. Di (p-phenoxybenzoyl) benzene was synthesised via the Friedel-Crafts benzoylationwith terephthaloydichloride and biphenylether as starting materials and anhydrous AlCl3 as the catalyst, while the dpop-PDV was synthesized via the McMurry coupling reaction. The polymerization was carried out in THF with TiCl4 and Zn as the catalyst and reducing agent respectively. Characterization on monomer and polymer had been carried out by using FTIR, GCMS, DSC, TGA, GPC and melting point measurement. Response of the polymer towards oxygen gas was described in terms of fluorescence spectra, repeatability, reproducibility and the response curve. Results obtained showed that the fluorescence intensity decreased upon exposure to O2 gas, indicating that the polymer was responsive to the presence of the O2 gas and the sample was found regenerable by flushing the polymer solution with N2 gas.

scholarly journals Synthesis and Properties of Nitrogen-Doped Carbon Quantum Dots Using Lactic Acid as Carbon Source

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 466
Author(s):  
Kaixin Chang ◽  
Qianjin Zhu ◽  
Liyan Qi ◽  
Mingwei Guo ◽  
Woming Gao ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Lactic Acid ◽  
Fluorescence Quenching ◽  
Functional Groups ◽  
Fluorescence Intensity ◽  
Carbon Quantum Dots ◽  
Nitrogen Doped ◽  
Ph Values ◽  
Wide Range ◽  
Nitrogen Doped Carbon

Nitrogen-doped carbon quantum dots (N-CQDs) were synthesized in a one-step hydrothermal technique utilizing L-lactic acid as that of the source of carbon and ethylenediamine as that of the source of nitrogen, and were characterized using dynamic light scattering, X-ray photoelectron spectroscopy ultraviolet-visible spectrum, Fourier-transformed infrared spectrum, high-resolution transmission electron microscopy, and fluorescence spectrum. The generated N-CQDs have a spherical structure and overall diameters ranging from 1–4 nm, and their surface comprises specific functional groups such as amino, carboxyl, and hydroxyl, resulting in greater water solubility and fluorescence. The quantum yield of N-CQDs (being 46%) is significantly higher than that of the CQDs synthesized from other biomass in literatures. Its fluorescence intensity is dependent on the excitation wavelength, and N-CQDs release blue light at 365 nm under ultraviolet light. The pH values may impact the protonation of N-CQDs surface functional groups and lead to significant fluorescence quenching of N-CQDs. Therefore, the fluorescence intensity of N-CQDs is the highest at pH 7.0, but it decreases with pH as pH values being either more than or less than pH 7.0. The N-CQDs exhibit high sensitivity to Fe3+ ions, for Fe3+ ions would decrease the fluorescence intensity of N-CQDs by 99.6%, and the influence of Fe3+ ions on N-CQDs fluorescence quenching is slightly affected by other metal ions. Moreover, the fluorescence quenching efficiency of Fe3+ ions displays an obvious linear relationship to Fe3+ concentrations in a wide range of concentrations (up to 200 µM) and with a detection limit of 1.89 µM. Therefore, the generated N-CQDs may be utilized as a robust fluorescence sensor for detecting pH and Fe3+ ions.

scholarly journals SINTESIS CALKON ((E)-1,3-DI(NAPHTHALEN-2-YL)PROP-2-EN-1-ONE) DAN AKTIVITASNYA SEBAGAI ANTIOKSIDAN

2012 ◽  
Vol 3 (1) ◽  
pp. 7-14
Author(s):  
Rahmiwati Hilma ◽  
Jasril ◽  
Hilwan Yuda Teruna
Keyword(s):  
Free Radical ◽  
Melting Point ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Room Temperature ◽  
Intermediate Compound ◽  
Alkaline Condition ◽  
Point Measurement ◽  
Anti Inflammatory ◽  
Layer Chromatography

Study on chalcone calkon (E)-1,3-di(naphthalen-2-yl)prop-2-en-1-one synthesis have been carried out with stirrer methode. These compounds can be used as intermediate compound to synthesize others compounds which was reported having antimicrobial, anti-inflammatory, anti-depressant, anti-tumour. The of chalcones synthesis vatives were reported in acid and alkali condition. In this study, chalcone and its derivates were synthesized by using stirrer method in alkaline condition in room temperature. the compounds subjected to somes analyses including melting point measurement, thin layer chromatography and HPLC. Scavenging free radical by using DPPH methode showed Scavenging free radical with LC50 >80 μg/ml min potent activity while the ascorbat acid LC50 89,79 μg/ml.

Quantum Dots CdSe/ZnS-Loaded Poly(D,L-Lactide-Co-Glycolide) Nanoparticles: Physicochemical Characterization and Application

2006 ◽  
Vol 505-507 ◽  
pp. 667-672 ◽  
Author(s):  
Chih Hui Yang ◽  
Kuo Chin Lin ◽  
Yu Huai Chang ◽  
Yu Cheng Lin
Keyword(s):  
Quantum Dots ◽  
Fluorescence Intensity ◽  
Fluorescence Spectra ◽  
Uv Light ◽  
Physicochemical Characterization ◽  
Plga Nanoparticles ◽  
Optimum Concentration ◽  
Cellular Internalization ◽  
Optimum Concentration Range

This paper described and characterized the quantum dots (QDs) with/without the polymeric PLGA applied in MC3T3E-1 delivery. Neat QDs were treated with various solvents, temperatures, exposure time and concentration to evaluate their stability and efficacy. We found that the intensity degree of fluorescence spectra (QDs) in different solvents follows the order: ether > THF > acetone > chloroform > methanol. Importantly, the QDs become inactive after 8-hr dissolution in the solvents of ether, THF or chloroform. According to this result, acetone and methanol are ideal solvents for QDs. The optimum concentration range of QDs in acetone is 5 to 10 mg/mL. We found that no obvious difference of fluorescence intensity was detected in QDs stored respectively at 4 °C, 24 °C and 44 °C (8-hour). When QDs were exposed to UV light (312 nm) for 2 hr, serious decay of fluorescence intensity was observed. In order to extend the application of QDs in medical areas, we encapsulated them in individual biocompatible poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles for in-vitro imaging of endocytosis in MC3T3E-1 cells. We demonstrated that the polymeric PLGA have the ability to permeate the cells for cellular internalization; the endocytotic activity could be enhanced by the polymeric QDs-encapsulated PLGA.

scholarly journals Establishment of Fluorescence Sensitization Method for Hydroxysafflor Yellow A

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
CAO Haiyan ◽  
QIN Xiude ◽  
LIU Chen ◽  
ZHAO Xinzhe ◽  
MA Yuhui ◽  
...  
Keyword(s):  
Detection Limit ◽  
Fluorescence Intensity ◽  
Fluorescence Spectra ◽  
Pharmacological Effects ◽  
Absorption And Fluorescence Spectra ◽  
Hydroxysafflor Yellow A ◽  
T24 Cells ◽  
Fluorescence Sensitization ◽  
In Cells

As the main active ingredient in Chinese medicine safflower, hydroxysafflor yellow A (HSYA) has multiple pharmacological effects. In the work, the absorption and fluorescence spectra of HSYA under different environmental conditions (such as acidity, temperature, ions, viscosity, and surfactant) were investigated. The fluorescence intensity of HSYA varied greatly with acidity, temperature, viscosity, and surfactant, but was less affected by common cations and anions. Among various surfactants, we found that borax can significantly enhance the HSYA fluorescence intensity, and thus, a borax-HSYA sensitization system for HSYA fluorescence was established. In the optimized sensitization system, the fluorescence intensity of HSYA increased by 20 times and showed a good linearity with HSYA concentrations in the range of 0∼10 μM with a detection limit of 8 nM. The borax-HSYA sensitization system is nontoxic to T24 cells and mice and can be used for the fluorescence imaging of HSYA in cells, thereby providing an effective method for analyzing HSYA in vitro and monitoring its metabolism in cells.

Study on Three-Dimensional Fluorescence Spectra of Oil Concentration in Water

2011 ◽  
Vol 322 ◽  
pp. 144-147
Author(s):  
Yu Tian Wang ◽  
Li Li Yang ◽  
Xin Qiong Lu
Keyword(s):  
Quantitative Analysis ◽  
Fluorescence Intensity ◽  
Fluorescence Spectra ◽  
Three Dimensional ◽  
Measurement Model ◽  
Excitation Wavelength ◽  
Experimental Basis ◽  
Oil In Water ◽  
Oil Concentration ◽  
Fluorescence Spectrometer

According to the Lambert-Beer laws, the fluorescence spectra of oil in water were investigated by measuring excitation-emission matrixes with FS920 fluorescence spectrometer. On the basis of the three-dimensional fluorescence spectra of oil in water, the excitation wavelength of 290nm and emission wavelength of 324nm were chosen for the quantitative analysis of oil in water. The results show that the concentration of oil in water is linearly proportional to the fluorescence intensity in the range of 1ppm-100ppm, and the measurement model of concentration is obtained with the linear correlation coefficient of 0.9993. The artificial samples has also been tested and the results are satisfactory. The recovery is in the range of 92%-106%. The research provides experimental basis for the quantitative analysis of multi-component oil in water.

ChemInform Abstract: Palladium Catalyzed Oxidative Suzuki Coupling Reaction of Indolizine at the 3-Position Using Oxygen Gas as the Only Oxidant.

ChemInform ◽  
2015 ◽  
Vol 46 (4) ◽  
pp. no-no
Author(s):  
Huayou Hu ◽  
Yong Liu ◽  
Juan Xu ◽  
Yuhe Kan ◽  
Chao Wang ◽  
...  
Keyword(s):  
Coupling Reaction ◽  
Suzuki Coupling ◽  
Suzuki Coupling Reaction ◽  
Palladium Catalyzed ◽  
Oxygen Gas

A naked-eye, selective and sensitive chemosensor for fluoride ion

2010 ◽  
Vol 64 (6) ◽  
Author(s):  
Puhui Xie ◽  
Fengqi Guo ◽  
Weifeng Wang ◽  
Xiyang Liu
Keyword(s):  
Charge Transfer ◽  
Fluorescence Quenching ◽  
Fluorescence Spectra ◽  
Color Change ◽  
Fluoride Ion ◽  
Absorption And Fluorescence Spectra ◽  
Strong Fluorescence ◽  
Naked Eye ◽  
Acridine Yellow ◽  
Intermolecular Charge Transfer

AbstractEffect of the addition of six different anions on the absorption and fluorescence spectra of acridine yellow G (AYG) was examined. Only the F− anion could induce a visible color change observable with naked eye and a strong fluorescence quenching with K SV of 8.3 × 104 mol−1 L in CH3CN solutions. Calculated results of the interaction between the F− anion and acridine yellow G using the B3LYP/6-31G(d) program showed that the intermolecular charge transfer through the formation of an H-bond between AYG and F− is an essential sensor mechanism.

scholarly journals Fluorimetric studies on the dimerization equilibrium of protoporphyrin IX and its haemato derivative

1983 ◽  
Vol 209 (2) ◽  
pp. 547-552 ◽  
Author(s):  
R Margalit ◽  
N Shaklai ◽  
S Cohen
Keyword(s):  
Ionic Strength ◽  
Fluorescence Quenching ◽  
Fluorescence Intensity ◽  
Salt Concentration ◽  
Equilibrium Constants ◽  
Protoporphyrin Ix ◽  
Constant Ionic Strength ◽  
Aggregation Process ◽  
Buffer Concentration ◽  
Common Anion

The aggregations of protoporphyrin IX and haematoporphyrin IX in aqueous solutions were studied by fluorimetric techniques. Porphyrin concentrations were limited to 0.001-0.1 microM and 0.01-1 microM for protoporphyrin and haematoporphyrin respectively, where dimerization is the dominant aggregation process. The dimerization equilibrium constants (at 25 degrees C, neutral pH, 50 mM-Tris/HCl buffer) were determined to be 3×10(7) M and 4×10(5) M for the proto and the haemato derivatives respectively. The fluorescence intensity of a given protoporphyrin solution (within the range indicated above) was markedly decreased by salts in the system, over the salt concentration range 0.1-7 mM at constant ionic strength, in the sequence CaCl2 greater than MgCl2 greater than KCl greater than NaCl. The direction of this effect, fluorescence quenching, suggests that these salts promote an increase in aggregation. The differences in the magnitudes of the effect, among different salt species sharing a common anion, at constant ionic strength, imply that the effect is cation-specific. In contrast, the fluorescence intensity of a given solution of haematoporphyrin (within the range indicated above) was unaffected by these salts, under similar concentrations, nor was it sensitive to the total buffer concentration, or to the type of buffer in the system.

Inner Filter Effect on Fluorescence Dyes Spectra in Methanol Solution

2016 ◽  
Vol 675-676 ◽  
pp. 704-707 ◽  
Author(s):  
Saksit Sukprasong ◽  
Yongyut Manjit ◽  
Apichart Limpichaipanit ◽  
Athipong Ngamjarurojana
Keyword(s):  
Fluorescence Intensity ◽  
Fluorescence Spectra ◽  
Inner Filter Effect ◽  
Fluorescent Dye ◽  
Concentration Effect ◽  
Wavelength Shift ◽  
Filter Effect ◽  
High Concentrations ◽  
Fluorescence Dyes ◽  
Dye Solutions

This research was conducted to study the inner filter effect on the fluorescence spectra of fluorescence dyes. The concentration effect on all of fluorescent dye solutions showed the same trend in terms of changes in fluorescence intensity spectra. At low concentrations, the fluorescence intensity increased when the concentration of fluorescent dye solution increased. However, at high concentrations, the fluorescence intensity decreased when the concentration of fluorescent dye solution increased. Interestingly, the result of fluorescence spectra in dye solutions showed that the fluorescence intensity maxima in all dye solutions were shifted to a higher wavelength (red-shift) when the concentration of fluorescent dye solution increased. The results of concentration effect on fluorescence intensity and wavelength-shift in dyes solution can be explained by inner filter effect on fluorescent dye solutions.

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