N,N'-bicarbazole-benzothiadiazole-based conjugated porous organic polymer for reactive oxygen species generation in live cells

2021 ◽  
Author(s):  
Subhankar Kundu ◽  
Biswajit Behera ◽  
Arkaprabha Giri ◽  
Nitu Saha ◽  
Abhijit Patra
Keyword(s):  
Reactive Oxygen Species ◽  
Visible Light ◽  
Light Absorption ◽  
Reactive Oxygen Species Generation ◽  
Organic Polymer ◽  
Live Cells ◽  
Oxygen Species ◽  
Visible Light Absorption ◽  
Porous Organic Polymer ◽  
Water Dispersible

A π-conjugated porous organic polymer (BCzBz) was fabricated employing N,N'-bicarbazole and benzothiadiazole as molecular building units exhibiting broad visible light absorption. The photostable, water-dispersible, and cytocompatible BCzBz was demonstrated as...

Augmentation of Photocatalytic Degradation of Oxytetracycline by Cu–CdS and Deciphering the Contribution of Reactive Oxygen Species

2020 ◽  
Vol 20 (10) ◽  
pp. 6245-6256
Author(s):  
Jing-Jing Tian ◽  
Chih-Kuei Chen ◽  
Joy Thomas ◽  
Chang-Tang Chang
Keyword(s):  
Reactive Oxygen Species ◽  
Visible Light ◽  
Hydroxyl Radicals ◽  
Superoxide Radical ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Deposition Method ◽  
Surface Loading ◽  
Visible Light Absorption ◽  
Scanning Electron

Production of Copper (Cu) modified Cadmium sulfide (CdS) nanomaterial, named as Cu–CdS, was successfully synthesized through hydrothermal and photo deposition method to degrade oxytetracycline (OTC) antibiotics in aqueous solution. Uniform surface loading of copper was observed on CdS using Scanning Electron Microscopy-mapping (SEM-mapping). The Cu induced improvement in the visible light absorption was observed using UV-vis absorption spectrum. Thus, this material can exhibit excellent oxytetracycline (OTC) degradation by photocatalysis. The best OTC degradation efficiency of 90% was be achieved under the optimal concentration of 4% Cu–CdS, with 0.1 g L−1 dosage (pH 5) under UV irradiation. 0.167 mg L−1 min−1 was observed as the reaction kL-H on the peripheral of the catalyst. In addition, OTC can also be degraded under visible light with removal efficiency approximately 90%. Moreover, the contribution of main reactive oxygen species (ROS), including hydroxyl radicals, superoxide radical and holes, is evaluated as 18%, 43% and 29%.

A smart photosensitizer based on a red emitting solution processable porous polymer: generation of reactive oxygen species

2018 ◽  
Vol 54 (66) ◽  
pp. 9123-9126 ◽  
Author(s):  
Sujoy Bandyopadhyay ◽  
Subhankar Kundu ◽  
Arkaprabha Giri ◽  
Abhijit Patra
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Structure Activity Relationship ◽  
Porous Polymer ◽  
Organic Polymer ◽  
Activity Relationship ◽  
Oxygen Species ◽  
Porous Organic Polymer ◽  
Structure Activity ◽  
Solution Processable

An efficient photosensitizer was developed employing a red emitting soluble conjugated porous organic polymer and the structure–activity relationship was established.

Impact of Rutile Fraction on TiO2 Visible-Light Absorption and Visible-Light-Induced Photocatalytic Activity

2018 ◽  
Author(s):  
David Maria Tobaldi ◽  
Luc Lajaunie ◽  
ana caetano ◽  
nejc rozman ◽  
Maria Paula Seabra ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Solid Phase ◽  
Diffraction Method ◽  
Band Alignment ◽  
Quantitative Phase Analysis ◽  
Transmission Microscopy ◽  
Visible Light Absorption ◽  
X Ray

<div>Titanium dioxide is by far the most utilised semiconductor material for photocatalytic applications. Still, it is transparent to visible-light. Recently, it has been proved that a type-II band alignment for the rutile−anatase mixture would improve its visible-light absorption.</div><div>In this research paper we thoroughly characterised the real crystalline and amorphous phases of synthesised titanias – thermally treated at different temperatures to get distinct ratios of anatase-rutile-amorphous fraction – as well as that of three commercially available photocatalytic nano-TiO2. </div><div>The structural characterisation was done via advanced X-ray diffraction method, namely the Rietveld-RIR method, to attain a full quantitative phase analysis of the specimens. The microstructure was also investigated via an advanced X-ray method, the whole powder pattern modelling. These methods were validated combining advanced aberration-corrected scanning transmission microscopy and high-resolution electron energy-loss spectroscopy. The photocatalytic activity was assessed in the liquid- and gas-solid phase (employing rhodamine B and 4-chlorophenol, and isopropanol, respectively, as the organic substances to degrade) using a light source irradiating exclusively in the visible-range.</div><div>Optical spectroscopy showed that even a small fraction of rutile (2 wt%) is able to shift to lower energies the apparent optical band gap of an anatase-rutile mixed phase. But is this enough to attain a real photocatalytic activity promoted by merely visible-light?</div><div>We tried to give a reply to that question.</div><div>Photocatalytic activity results in the liquid-solid phase showed that a high surface hydroxylation led to specimen with superior visible light-induced catalytic activity (i.e. dye and ligand-to-metal charge transfer complexes sensitisation effects). That is: not photocatalysis <i>sensu-strictu</i>.</div><div>On the other hand, the gas-solid phase results showed that a higher amount of the rutile fraction (around 10 wt%), together with less recombination of the charge carriers, were more effective for an actual photocatalytic oxidation of isopropanol.</div>

Роль оксида азота в реализации антиоксидантного эффекта неопиатного аналога лей-энкефалина в сердце новорожденных белых крыс

2019 ◽  
pp. 61-64
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen Species Generation ◽  
Reactive Oxygen ◽  
Postnatal Period ◽  
Oxide System ◽  
No Synthase ◽  
Albino Rats ◽  
Oxygen Species ◽  
Control Parameters ◽  
Synthase Inhibitor

The eff ect of the non-opiate analog of leu-enkephalin (peptide NALE: Phe – D – Ala – Gly – Phe – Leu – Arg) on the reactive oxygen species generation in the heart of albino rats in the early postnatal period was studied. Peptide NALE was administered intraperitoneally in the dose of 100 μ/kg daily from 2 to 6 days of life. Reactive oxygen species generation was assessed by chemiluminescence in the heart homogenates of 7-day-old animals. Decreasing of reactive oxygen species generation nearly by 30 % and an increasing in antioxidant system activity by the 20-27 %, compared with the control parameters, were found. The antioxidant eff ect of peptide NALE is associated with the presence of the amino acid Arg in the structure of the peptide. An analogue of NALE peptide, devoid of Arg (peptide Phe – D – Ala – Gly – Phe – Leu – Gly), had a signifi cant lower antioxidant eff ect. The NO-synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) in the dose 50 mg/kg, administered with NALE peptide, reduced the severity of the NALE antioxidant eff ect. The results of the study suggest that the pronounced antioxidant eff ect of NALE peptide in the heart of albino rats, at least in part, is due to the interaction with the nitric oxide system.

Photoassisted Production of O2-• and H2 in Aqueous Medium Stimulated by Polythiophene in ZSM-5 Zeolite Channels

1999 ◽  
Vol 64 (1) ◽  
pp. 149-156 ◽  
Author(s):  
Gabriel Čík ◽  
František Šeršeň ◽  
Alena Bumbálová
Keyword(s):  
Reactive Oxygen Species ◽  
Ion Exchange ◽  
Visible Light ◽  
Aqueous Medium ◽  
Exchange Reaction ◽  
Epr Spectroscopy ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Water Reduction ◽  
Ion Exchange Reaction

The formation of reactive oxygen species due to irradiation by a visible light of the polythiophene deposited in ZSM-5 zeolite channels in aqueous medium has been studied. Polymerization of thiophene was carried out in zeolite channels after the ion-exchange reaction of Na+ for Fe3+. By means of EPR spectroscopy, the temporarily generated 1O2 in irradiated aqueous medium was proved. The formation of O2-• was confirmed by the reduction of Fe3+-cytochrome c. Irradiation led to the water reduction to hydrogen.

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