scholarly journals Condensation Product of 5-Bromosalicylaldehyde and Amino Phenol: Fluorescence Sensor for Ascorbic Acid and AND Logic Gate

Author(s):  
Bidisha Bharali ◽  
Diganta Kumar Das

Abstract Condensation product of 5-bromosalicylaldehyde and aminophenol (L) has been synthesised and characterised. Fluorescence of L enhances by 23 times on interaction with Ce3+ while it is quenched completely by Ce4+. Ascorbic acid (AA) is a well known strong reducing agent and this property has been used to act L:Ce4+ adduct as a fluorescence “on” sensor for AA. AA reduces Ce4+ into Ce3+ and thereby increasing fluorescence of L due to the formation of L:Ce3+ adduct. Molecules which generally coexist with AA viz. Cholesterol, Glucose, Sucrose and Dopamine found not to interfere. The interaction of L with Ce3+, Ce4+ and subsequently with AA has been verified with cyclic voltammetry.

2018 ◽  
Author(s):  
Chandan Dey ◽  
Ronny Neumann

<p>A manganese substituted Anderson type polyoxometalate, [MnMo<sub>6</sub>O<sub>24</sub>]<sup>9-</sup>, tethered with an anthracene photosensitizer was prepared and used as catalyst for CO<sub>2</sub> reduction. The polyoxometalate-photosensitizer hybrid complex, obtained by covalent attachment of the sensitizer to only one face of the planar polyoxometalate, was characterized by NMR, IR and mass spectroscopy. Cyclic voltammetry measurements show a catalytic response for the reduction of carbon dioxide, thereby suggesting catalysis at the manganese site on the open face of the polyoxometalate. Controlled potentiometric electrolysis showed the reduction of CO<sub>2</sub> to CO with a TOF of ~15 sec<sup>-1</sup>. Further photochemical reactions showed that the polyoxometalate-anthracene hybrid complex was active for the reduction of CO<sub>2</sub> to yield formic acid and/or CO in varying amounts dependent on the reducing agent used. Control experiments showed that the attachment of the photosensitizer to [MnMo<sub>6</sub>O<sub>24</sub>]<sup>9-</sup> is necessary for photocatalysis.</p><div><br></div>


2021 ◽  
Author(s):  
Yifei Guo ◽  
Jingjing Du ◽  
Jianjun Li ◽  
Ran Yang ◽  
Peter B. de Harrington ◽  
...  

In this work, cysteamine-coated CdTe quantum dots (CA-CdTe QDs) were synthesized by a simple hydrothermal method employing cadmium chloride as the cadmium source and cysteamine hydrochloride as the functional monomer....


2021 ◽  
Vol 121 ◽  
pp. 111622
Author(s):  
Li Chen ◽  
Limin Zheng ◽  
Fangqi Wang ◽  
Simin Yi ◽  
Donghao Liu ◽  
...  

2019 ◽  
Vol Vol. 14, No.1 ◽  
pp. 5-14 ◽  
Author(s):  
Anastasiya Tkachenko ◽  
Mykyta Onizhuk ◽  
Oleg Tkachenko ◽  
Leliz T. Arenas ◽  
Edilson V. Benvenutt ◽  
...  

In the present study, an electrochemical sensor based on the electrode (SiMImCl/C) consisting of graphite and silica, grafted with 1-n-propyl-3-methylimidazolium chloride was used for ascorbic acid (AA) quantification in pharmaceuticals and food formulations. Cyclic voltammetry and electrochemical impedance spectroscopy were applied for electrochemical characterization of the SiMImCl/C electrode. The cyclic voltammetry study revealed that the oxidation of AA on this electrode is an irreversible process, realized by adsorption and diffusion limited step. The differential pulse voltammetry was applied to develop a procedure for the AA determination. The linear range was found to be 0.3–170 μmol L-1 and the limit of detection – 0.1 μmol L-1. The proposed SiMImCl/C electrode has long term stability and does not show electrochemical activity towards the analytes, which commonly coexist with AA. The sensor was successfully used for quantification of AA in food and pharmaceutical formulations.


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