scholarly journals Microwave-assisted one-pot multicomponent synthesis of indole derived fluorometric probe for detection of Co2+ ions

2021 ◽  
Vol 24 (02) ◽  
Author(s):  
Rizana Azees ◽  
Asitha T. Cooray ◽  
K.G.U.R. Kumarasinghe
Keyword(s):  
Fluorescence Enhancement ◽  
Free Ligand ◽  
Emission Spectra ◽  
Ultra Violet ◽  
Excitation Wavelength ◽  
Stoichiometric Ratio ◽  
Multicomponent Synthesis ◽  
One Pot ◽  
Long Term Stability

Cobalt (Co2+) is an essential constituent in the human body while excessive exposure leads to severe systemic toxic reactions which highlight the importance of developing effective methods to detect Co2+ ions. A simple and highly efficient fluorescence enhanced turn OFF-ON chemosensor was synthesized to detect the paramagnetic Co2+. The ligand, N-((1H-indol-3-yl)(phenyl)methyl)aniline (L), was synthesized in 92% yield by means of hydrated ferric chloride catalyzed one -pot multicomponent microwave irradiation in the presence of Indole, benzaldehyde, and aniline as reactants. The major green principles of waste prevention, high atom economy (94.3%), green solvent, higher energy efficiency, and catalysis were the highlights of the ligand synthesis. The ligand exhibited remarkable fluorescence enhancement with Co2+ and a turn ON ratio of over 160-fold in MeOH/H2O (at pH 3.5) solution at an excitation wavelength of 369 nm in the Ultra-Violet range. The detection limit of L- Co2+ was 2.2 μM. The excitation and the emission spectra indicated stoke’s shift of 93 nm which supports the fluorescence enhancement observed in L- Co2+ with respect to the free ligand. The Job’s plot indicated fluorometric sensing of Co2+ ascribed to the complex formation with a stoichiometric ratio of 2:1 (L- Co2+). Furthermore, the high linearity (r2 =0.992) observed in the Benesi Hildebrand plot in a wide concentration range of 0.5−80 μM confirmed the above stoichiometric ratio. The association constant (Ka) for the L-Co2+ was determined to be 8.382 ×1 04 M−1 ± 5.8 ×103M−1.The prepared Co2+ fluorometric probe indicated long-term stability in −18 ℃ up to 45 days. Furthermore, the presence of Fe2+ and Fe3+ in the medium with Co2+ exhibited an interference effect in the fluorescence intensities. Upon further concentration studies, it was evident that the interference of Fe2+ and Fe3+ starts around 10.00 μM and rises exponentially. Keywords: MCR, Green synthesis, Fluorescent Chemo-sensor, Turn OFF-ON, Cobalt (II), indole derivatives

scholarly journals “Smart” Triiodide Compounds: Does Halogen Bonding Influence Antimicrobial Activities?

Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 182 ◽  
Author(s):  
Edis ◽  
Haj Bloukh ◽  
Abu Sara ◽  
Bhakhoa ◽  
Rhyman ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Biological Activities ◽  
Microstructural Analysis ◽  
Halogen Bonding ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
One Pot ◽  
Long Term Stability ◽  
Free Iodine

Antimicrobial agents containing symmetrical triiodides complexes with halogen bonding may release free iodine molecules in a controlled manner. This happens due to interactions with the plasma membrane of microorganisms which lead to changes in the structure of the triiodide anion. To verify this hypothesis, the triiodide complex [Na(12-crown-4)2]I3 was prepared by an optimized one-pot synthesis and tested against 18 clinical isolates, 10 reference strains of pathogens and five antibiotics. The antimicrobial activities of this symmetrical triiodide complex were determined by zone of inhibition plate studies through disc- and agar-well-diffusion methods. The triiodide complex proved to be a broad spectrum microbicidal agent. The biological activities were related to the calculated partition coefficient (octanol/water). The microstructural analysis of SEM and EDS undermined the purity of the triiodide complex. The anionic structure consists of isolated, symmetrical triiodide anions [I-I-I]- with halogen bonding. Computational methods were used to calculate the energy required to release iodine from [I-I-I]- and [I-I···I]-. The halogen bonding in the triiodide ion reduces the antibacterial activities in comparison to the inhibitory actions of pure iodine but increases the long term stability of [Na(12-crown-4)2]I3.

scholarly journals Factors affecting the long-term stability of mesoporous nickel-based catalysts in combined steam and dry reforming of methane

2016 ◽  
Vol 6 (12) ◽  
pp. 4616-4631 ◽  
Author(s):  
K. Jabbour ◽  
N. El Hassan ◽  
A. Davidson ◽  
S. Casale ◽  
P. Massiani
Keyword(s):  
Dry Reforming ◽  
Coke Deposition ◽  
Dry Reforming Of Methane ◽  
One Pot ◽  
Factors Affecting ◽  
Term Stability ◽  
Long Term Stability ◽  
Highly Efficient ◽  
One Pot Synthesis

Direct “one-pot” synthesis is highly efficient to obtain performing mesoporous Ni–Al2O3catalysts able to resist deactivation by sintering and coke deposition during CH4reforming by CO2and H2O to produce “metgas”.

Strong Down-Conversion Emission of Sm3+ Doped Borotellurite Glass under 480 nm Excitation Wavelength

2016 ◽  
Vol 705 ◽  
pp. 204-208
Author(s):  
Siti Nasuha Rafien ◽  
Azman Kasim ◽  
Azhan Hashim ◽  
S. Akmal Syamsyir ◽  
Mardhiah Abdullah ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Emission Spectra ◽  
Ultra Violet ◽  
Luminescence Spectra ◽  
Excitation Wavelength ◽  
Physical Parameters ◽  
Tellurite Glasses ◽  
Physical And Chemical ◽  
Down Conversion ◽  
And Chemical Properties

Tellurite glasses were generally applied in rare earth optical materials due to their excellent in physical and chemical properties. In this study, tellurite glasses composed of (70-x)TeO2-20B2O3-10ZnO-xSm2O3 (x = 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol %) were prepared by conventional melt-quenching technique. Some basic physical parameters such as density, molar volume and oxygen packing density as well as the optical analysis by mean of their absorption and emission spectra have been carried out at room temperature using UV/Vis and photoluminescence spectrophotometer. The result of physical properties are found to vary with respect to concentration of Sm3+ ions content. Meanwhile, three strong absorption peaks are observed and are well resolved in the ultra violet and visible regions due to transitions between the ground state and various excited state of Sm3+ ions. Under 480nm laser excitation, luminescence spectra exhibit four emission bands at 562 nm, 599 nm, 645 nm and 706 nm which corresponding to the transition 4G5/2 → 6H5/2, 4G5/2 → 6H7/2, 4G5/2 → 6H9/2 and 4G5/2 → 6H11/2 were observed. Some other results were also been analysed and presented.

scholarly journals Long term stability of air processed inkjet infiltrated carbon-based printed perovskite solar cells under intense ultra-violet light soaking

2017 ◽  
Vol 5 (10) ◽  
pp. 4797-4802 ◽  
Author(s):  
Syed Ghufran Hashmi ◽  
Armi Tiihonen ◽  
David Martineau ◽  
Merve Ozkan ◽  
Paola Vivo ◽  
...  
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Ultra Violet ◽  
Light Illumination ◽  
Ultra Violet Light ◽  
Term Stability ◽  
Long Term Stability ◽  
Violet Light ◽  
Carbon Based

The long term stability of air processed inkjet infiltrated carbon based perovskite solar cells (CPSCs) is investigated under intense ultra-violet light soaking equivalent to 1.5 Sun UV light illumination.

Ethylene glycol-mediated one-pot synthesis of Fe incorporated α-Ni(OH)2 nanosheets with enhanced intrinsic electrocatalytic activity and long-term stability for alkaline water oxidation

2021 ◽  
Author(s):  
Venkataramanan Mahalingam ◽  
Gouri Tudu ◽  
Sourav Ghosh ◽  
Sagar Ganguli ◽  
Murthy Koppsetti ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Water Splitting ◽  
Nickel Hydroxide ◽  
Oxygen Evolution Reaction ◽  
Water Oxidation ◽  
Electrocatalytic Activity ◽  
One Pot ◽  
Long Term Stability ◽  
Pure Phase

Sustainable electrocatalytic water splitting stipulates development of cheap, efficient and stable electrocatalysts to promote comparatively sluggish oxygen evolution reaction. We have synthesized iron incorporated pure phase α-nickel hydroxide, Ni0.8Fe0.2(OH)2 electrocatalyst...

scholarly journals Facile one-pot solvothermal preparation of two-dimensional Ni-based metal–organic framework microsheets as a high-performance supercapacitor material

RSC Advances ◽  
2021 ◽  
Vol 11 (14) ◽  
pp. 8362-8366
Author(s):  
Zhaohua Li ◽  
Yuan Sun ◽  
Rui Hu ◽  
Shuai Ye ◽  
Jun Song ◽  
...  
Keyword(s):  
High Performance ◽  
Metal Organic Framework ◽  
Two Dimensional ◽  
Supercapacitor Electrode ◽  
One Pot ◽  
Long Term Stability ◽  
Metal Organic ◽  
Solvothermal Preparation ◽  
Organic Framework

Two-dimensional Ni-based metal–organic framework microsheets (Ni-MOFms) were synthesized via a facial one-pot solvothermal approach and exhibited good specific capacities and excellent long-term stability when used for a supercapacitor electrode.

scholarly journals Bio-Based Hotmelt Adhesives with Well-Adhesion in Water

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 666
Author(s):  
Xi Yu ◽  
Chuang Dong ◽  
Wei Zhuang ◽  
Dongjian Shi ◽  
Weifu Dong ◽  
...  
Keyword(s):  
Adhesion Strength ◽  
One Pot ◽  
Adhesion Properties ◽  
Wet Adhesion ◽  
Initial Strength ◽  
Term Stability ◽  
Long Term Stability ◽  
Low Viscosity ◽  
A Value

We suggest a simple idea of bio-based adhesives with strong adhesion even under water. The adhesives simply prepared via polycondensation of 3,4-dihydroxyhydrocinnamic acid (DHHCA) and lactic acid (LA) in one pot polymerization. Poly(DHHCA-co-LA) has a hyperbranched structure and demonstrated strong dry and wet adhesion strength on diverse material surfaces. We found that their adhesion strength depended on the concentration of DHHCA. Poly(DHHCA-co-LA) with the lowest concentration of DHHCA showed the highest adhesion strength in water with a value of 2.7 MPa between glasses, while with the highest concentration of DHHCA it exhibited the highest dry adhesion strength with a value of 3.5 MPa, which was comparable to commercial instant super glue. Compared to underwater glues reported previously, our adhesives were able to spread rapidly under water with a low viscosity and worked strongly. Poly(DHHCA-co-LA) also showed long-term stability and kept wet adhesion strength of 2.2 MPa after steeping in water for 1 month at room temperature (initial strength was 2.4 MPa). In this paper, Poly(DHHCA-co-LA) with strong dry and wet adhesion properties and long-term stability was demonstrated for various kinds of applications, especially for wet conditions.

scholarly journals Construction of a Turn-off-on Fluorescent System Based On Aggregation Induced Emission of Acetaldehyde Using Carbonized Polymer Dots and Tb3+

2021 ◽  
Author(s):  
Rentian Guan ◽  
Shuai Zhang ◽  
Xiaoyu Fan ◽  
Xiaodong Shao ◽  
Yingying Hu ◽  
...  
Keyword(s):  
Fluorescence Enhancement ◽  
Limit Of Detection ◽  
Excitation Wavelength ◽  
Enhancement Effect ◽  
Blue Fluorescence ◽  
One Pot ◽  
Aggregation Induced Emission ◽  
Polymer Dots ◽  
The One ◽  
First Time

Abstract It was the first time to report the aggregation induced emission (AIE) of acetaldehyde (AA) on the surface of carbonized polymer dots (CPDs) with the auxiliary of Tb3+. Based on the AIE of AA, a turn-off-on fluorescence method was established for AA detection using the porous CPDs-Tb3+ system. The one-pot hydrothermal method was used to obtain CPDs, using milk and polyethyleneimine (PEI) as precursors. In the presence of Tb3+, CPDs aggregated immediately, and the fluorescence intensity decreased obviously for the precipitate. AA can effectively embed on the surface of CPDs-Tb3+ due to the porous structure. AA displayed obviously blue fluorescence with excitation wavelength at 370 nm (emission peak at 460 nm), while there was no fluorescence peak when excited at 460 nm. In the CPDs-Tb3+ solution, AA exhibits obvious fluorescence enhancement effect (lex 460 nm, lem 545 nm). And then, AA can be determined by the turn-off-on system based on the linear relationship between fluorescence enhancement and the concentration of AA ranging from 0.04 mM to 42.48 mM. The limit of detection (LOD) was 0.02 mM. The turn-off-on system was successfully applied to determine AA in wine samples. The strategy may be exploited to monitor AA in more drinking or foodstuff samples.

scholarly journals One-Pot Hydrothermal Synthesis of Carbon Dots as Fluorescent Probes for the Determination of Mercuric and Hypochlorite Ions

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1831
Author(s):  
Hsin Lee ◽  
Yen-Chang Su ◽  
Hsiang-Hao Tang ◽  
Yu-Sheng Lee ◽  
Jan-Yee Lee ◽  
...  
Keyword(s):  
Fluorescence Intensity ◽  
Fluorescent Probes ◽  
Carbon Dots ◽  
Limit Of Detection ◽  
Tap Water ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Excitation Wavelength ◽  
One Pot ◽  
Fluorescence Emission Spectra

Nitrogen and sulfur codoped carbon dots (NSCDs) were synthesized via a one-pot hydrothermal method, and citric acid, ethylenediamine, and methyl blue were used as precursors. The obtained NSCDs were spherical with an average size of 1.86 nm. The fluorescence emission spectra of the NSCDs were excitation independent and emitted blue fluorescence at 440 nm with an excitation wavelength at 350 nm. The quantum yield of the NSCDs was calculated to be 68.0%. The NSCDs could be constructed as fluorescent probes for highly selective and sensitive sensing mercuric (Hg2+) and hypochlorite (ClO−) ions. As the addition of Hg2+ or ClO− ions to the NSCDs, the fluorescence intensity was effectively quenched due to dynamic quenching. Under the optimal conditions, the linear response of the fluorescence intensity ranged from 0.7 μM to 15 μM with a detection limit of 0.54 μM and from 0.3 μM to 5.0 μM with a limit of detection of 0.29 μM for Hg2+ and ClO− ions, respectively. Finally, the proposed method was successfully used for quantifying Hg2+ and ClO− ions in spiked tap water samples.

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