scholarly journals Fluorescence quenching detection of UO2 2+ in aqueous solution based on an organic molecule probe of 6-chloro-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide

2021 ◽  
Vol 40 (1) ◽  
pp. 136-143
Author(s):  
Amira A. Elabd ◽  
Olivea A. Elhefnawy
Keyword(s):  
Detection Limit ◽  
Fluorescence Quenching ◽  
Fluorescence Intensity ◽  
Organic Molecule ◽  
Dynamic Range ◽  
Fluorescent Sensor ◽  
Transfer Processes ◽  
Electron Transfer Processes ◽  
Sulfonamide Group ◽  
Positively Charged

Abstract A new organic molecule probe has been introduced as a “turn-off” fluorescent sensor to detect trace quantities of UO2 2+ in the presence of several transition metals with promising results. The procedure is based on quenching the fluorescence intensity of 6-chloro-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide (L) in the presence of various UO2 2+ concentrations in methanol. The UO2 2+ and L species interact through electrostatic interaction between negatively charged nitrogen atom of the sulfonamide group of L and positively charged UO2 2+, thus facilitating the non-radiative recombination of UO2 2+ and L through the charge transfer or electron transfer processes and leading to the fluorescence quenching of L. The mechanism of quenching was addressed and proved to be static quenching. The impressive quenching of the fluorescence intensity of L by different concentrations of UO2 2+ has been successfully used as a new sensor to measure UO2 2+ in methanol at λ ex = 340 nm, λ em = 380 nm with a linear dynamic range of 0.08–5.0 µM and detection limit and quantification limit of 0.0276 and 0.0837 µM, respectively. The L sensor shows interesting advantages compared to other developed sensors with adequate performance, such as broader linear range and lower detection limit, selectivity, and simplicity, which illustrate its useful practical use.

Label-Free Aptamer Fluorescence Determination of Trace Pb2+ Using AuPd Nanoalloy Probe as Catalyst

2013 ◽  
Vol 631-632 ◽  
pp. 18-21 ◽  
Author(s):  
Zhi Liang Jiang ◽  
Mei Ling Tang ◽  
Qing Ye Liu ◽  
Ai Hui Liang
Keyword(s):  
Detection Limit ◽  
Fluorescence Quenching ◽  
Fluorescence Intensity ◽  
Water Samples ◽  
Catalytic Effect ◽  
Rhodamine 6G ◽  
Label Free ◽  
Double Stranded Dna ◽  
Fluorescence Determination

In the condition of 1.24 mmol/L EDTANa2, 16.7 mmol/L NaCl and 0.17 mmol/L Tris, the substrate chain of double-stranded DNA (dsDNA) could be cracked by Pb2+ to release single-stranded DNA (ssDNA) that adsorb onto AuPd nanoparticle (AuPdNP) and form stable AuPdNP-ssDNA, but the dsDNA can not protect AuPdNP that were aggregated to big AuPdNP aggregations (AuPdNPA) under the action of NaCl. The AuPdNP-ssDNA and AuPdNPA could be separated by centrifugation. With the concentration of Pb2+ increased, the released ssDNA increased, the AuPdNP-ssDNA in centrifugation solution increased and the catalytic effect enhanced on the fluorescence quenching reaction of Rhodamine 6G (Rh6G) and NaH2PO2, which led the fluorescence intensity at 552nm to decrease. The decreased fluorescence intensity (ΔF552nm) was linear to the concentration of Pb2+ in the range of 0.33-8.00 nmol/L, a detection limit of 0.21 nmol/L. The proposed method was applied to detect Pb2+ in water samples, with satisfactory results.

Fluorescent Sensor and Application in Determination of Carbaryl Residues

2014 ◽  
Vol 955-959 ◽  
pp. 1220-1223
Author(s):  
Ji Cheng Xu ◽  
Xin Shan Rong ◽  
Ting Tian ◽  
Feng Xian Qiu
Keyword(s):  
Detection Limit ◽  
Complex Formation ◽  
Fluorescence Intensity ◽  
Fluorescent Sensor ◽  
Inclusion Complex Formation ◽  
Cyclodextrin Derivative ◽  
Vegetable Samples ◽  
The Stability ◽  
Sensitive Method

The inclusion complex formation between fluorescent sensor 3, 3’-benzidine/β-cyclodextrin derivative (BDCD) and pesticide carbaryl was studied and characterized by TEM, XRD and fluorescence spectroscopy. The stability constant and the stoichiometry of complex were determined. Based on the enhancement of the fluorescence intensity of carbaryl produced through complex formation, a new sensitive method for the determination of carbaryl was established. The linear relationship between the fluorescence intensity and carbaryl concentration was obtained in the range of 0.60-3.00 μmol/L with a correlation coefficient of 0.9946. The detection limit was 5.12 nmol/L. This method has been successfully applied to the determination of carbaryl pesticide residue in water, fruit and vegetable samples with satisfactory results, recoveries in the range of 94.12 % to 105.88 % were obtained. The method is rapid, simple, direct, economical, sensitive and useful for carbaryl analysis.

The photo-initiation of the polymerization of vinyl compounds by means of cerous ions

1963 ◽  
Vol 275 (1361) ◽  
pp. 161-174 ◽  
Keyword(s):  
Electron Transfer ◽  
Fluorescence Quenching ◽  
Methacrylic Acid ◽  
Polymerization Reaction ◽  
Hydrogen Ions ◽  
Transfer Processes ◽  
Flash Technique ◽  
Electron Transfer Processes ◽  
Kinetics Of

The kinetics of the polymerization of acrylonitrile and methacrylic acid photosensitized by cerous ions have been studied. Cerous salts have been photolyzed in different media by means of the flash technique and ceric ions were produced, accompanied by fluorescence. Quenching of the fluorescence of the excited ceric species has been investigated with and without the presence of monomer and it has been demonstrated that hydrogen ions are necessary for the polymerization reaction to proceed. The results are consistent with the following electron transfer processes: Ce 3+ . HOH + hv ^+ (Ce 4+ . HOH - )*, Ce 4+ . HOH - )* hv ^+ Ce 3+ . HOH+ hv ", Ce 4+ . HOH - )* +H + ->Ce 4+ . H 2 O+H', Ce 4+ . HOH - )* +H + + M ->Ce 4+ +H 2 M H', where M = monomer.

scholarly journals An Acridine-Based Fluorescent Sensor for Monitoring ClO− in Water Samples and Zebrafish

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4764
Author(s):  
Su Chan Lee ◽  
Soyoung Park ◽  
Haeri So ◽  
Gyudong Lee ◽  
Ki-Tae Kim ◽  
...  
Keyword(s):  
Detection Limit ◽  
Fluorescence Quenching ◽  
Water Samples ◽  
Fluorescent Sensor ◽  
Aldehyde Group ◽  
Fluorescent Chemosensor ◽  
Synthetic Route

A novel acridine-based fluorescent chemosensor, BK ((E)-2-((acridine-9-ylimino)methyl)-N-benzhydrylhydrazine-1-carbothioamide), for monitoring ClO− was prepared. The sensor BK was synthesized by introducing a new synthetic route of making aldehyde group using formic hydrazide. Probe BK displayed notable fluorescence quenching in the presence of ClO− and showed a great selectivity over other guest analytes. The detection limit was calculated to be 7.65 μM. Additionally, BK was satisfactorily applied for sensing ClO− in water samples and zebrafish.

scholarly journals RuIII(edta) complexes as molecular redox catalysts in chemical and electrochemical reduction of dioxygen and hydrogen peroxide: inner-sphere versus outer-sphere mechanism

RSC Advances ◽  
2021 ◽  
Vol 11 (35) ◽  
pp. 21359-21366
Author(s):  
Debabrata Chatterjee ◽  
Marta Chrzanowska ◽  
Anna Katafias ◽  
Maria Oszajca ◽  
Rudi van Eldik
Keyword(s):  
Hydrogen Peroxide ◽  
Electron Transfer ◽  
Electrochemical Reduction ◽  
Molecular Oxygen ◽  
Outer Sphere ◽  
Transfer Processes ◽  
Edta Complexes ◽  
Inner Sphere ◽  
Electron Transfer Processes ◽  
Sphere Mechanism

[RuII(edta)(L)]2–, where edta4– =ethylenediaminetetraacetate; L = pyrazine (pz) and H2O, can reduce molecular oxygen sequentially to hydrogen peroxide and further to water by involving both outer-sphere and inner-sphere electron transfer processes.

scholarly journals A Novel Thiosemicarbazide-Based Fluorescent Chemosensor for Hypochlorite in Near-Perfect Aqueous Solution and Zebrafish

Chemosensors ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 65
Author(s):  
Minji Lee ◽  
Donghwan Choe ◽  
Soyoung Park ◽  
Hyeongjin Kim ◽  
Soomin Jeong ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Reactive Oxygen Species ◽  
Aqueous Solution ◽  
Fluorescence Quenching ◽  
Limit Of Detection ◽  
Fluorescent Sensor ◽  
Ionization Mass ◽  
Oxygen Species ◽  
Marked Selectivity ◽  
Uv Visible

A novel thiosemicarbazide-based fluorescent sensor (AFC) was developed. It was successfully applied to detect hypochlorite (ClO−) with fluorescence quenching in bis-tris buffer. The limit of detection of AFC for ClO− was analyzed to be 58.7 μM. Importantly, AFC could be employed as an efficient and practical fluorescent sensor for ClO− in water sample and zebrafish. Moreover, AFC showed a marked selectivity to ClO− over varied competitive analytes with reactive oxygen species. The detection process of AFC to ClO− was illustrated by UV–visible and fluorescent spectroscopy and electrospray ionization–mass spectrometry (ESI–MS).

Photoinduced electron transfer in mechanically interlocked suit[3]ane systems

2021 ◽  
Author(s):  
Anton J Stasyuk ◽  
Olga A. Stasyuk ◽  
Miquel Solà ◽  
Alexander Voityuk
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
New Class ◽  
Transfer Processes ◽  
Two Component ◽  
Electron Transfer Processes

Suitanes, a new class of two-component mechanically interlocked systems, have recently been developed. In this work, we report a detailed study of photoinduced electron transfer processes in the suit[3]anes consisting...

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