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.

scholarly journals Photo-Responsive Supramolecular Micelles for Controlled Drug Release and Improved Chemotherapy

2020 ◽  
Vol 22 (1) ◽  
pp. 154
Author(s):  
Fasih Bintang Ilhami ◽  
Kai-Chen Peng ◽  
Yi-Shiuan Chang ◽  
Yihalem Abebe Alemayehu ◽  
Hsieh-Chih Tsai ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Drug Release ◽  
Visible Light ◽  
Cancer Cells ◽  
Laser Irradiation ◽  
Reactive Oxygen ◽  
Controlled Drug Release ◽  
Grand Challenge ◽  
Supramolecular System ◽  
Oxygen Species

Development of stimuli-responsive supramolecular micelles that enable high levels of well-controlled drug release in cancer cells remains a grand challenge. Here, we encapsulated the antitumor drug doxorubicin (DOX) and pro-photosensitizer 5-aminolevulinic acid (5-ALA) within adenine-functionalized supramolecular micelles (A-PPG), in order to achieve effective drug delivery combined with photo-chemotherapy. The resulting DOX/5-ALA-loaded micelles exhibited excellent light and pH-responsive behavior in aqueous solution and high drug-entrapment stability in serum-rich media. A short duration (1–2 min) of laser irradiation with visible light induced the dissociation of the DOX/5-ALA complexes within the micelles, which disrupted micellular stability and resulted in rapid, immediate release of the physically entrapped drug from the micelles. In addition, in vitro assays of cellular reactive oxygen species generation and cellular internalization confirmed the drug-loaded micelles exhibited significantly enhanced cellular uptake after visible light irradiation, and that the light-triggered disassembly of micellar structures rapidly increased the production of reactive oxygen species within the cells. Importantly, flow cytometric analysis demonstrated that laser irradiation of cancer cells incubated with DOX/5-ALA-loaded A-PPG micelles effectively induced apoptotic cell death via endocytosis. Thus, this newly developed supramolecular system may offer a potential route towards improving the efficacy of synergistic chemotherapeutic approaches for cancer.

Photocatalytic Degradation of 4-Chlorophenol by •OH Radicals Generated by Thiophene Oligomers Incorporated in ZSM-5 Zeolite Channels

2003 ◽  
Vol 68 (11) ◽  
pp. 2219-2230 ◽  
Author(s):  
Gabriel Čík ◽  
Milada Hubinová ◽  
František Šeršeň ◽  
Jozef Krištín ◽  
Monika Antošová
Keyword(s):  
Reactive Oxygen Species ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Maleic Acid ◽  
Aqueous Suspension ◽  
Reactive Oxygen ◽  
Spin Trapping ◽  
Oh Radicals ◽  
Oxygen Species ◽  
Trapping Method

Degradation of 4-chlorophenol by reactive oxygen species was studied, the latter being generated by photo-assisted reactions of thiophene oligomers, synthesized in channels of the Na-ZSM-5 zeolite. The photoreaction was carried out in an aqueous suspension of photocatalyst, irradiated with visible light (λ > 400 nm). The spin-trapping method was used to detect the generated •OH radicals. The main products of the photodecomposition of 4-chlorophenol were found to be phenol, hydroquinone and maleic acid.

Top-down fabrication of Ti doped BiVO4 nanosheets for efficient water oxidation under visible light

2021 ◽  
Author(s):  
Bei Peng ◽  
Yawen Shi ◽  
Xin Zhang ◽  
Peiwen Lv
Keyword(s):  
Solid State ◽  
Ion Exchange ◽  
Visible Light ◽  
Exchange Reaction ◽  
Solid State Reaction ◽  
Water Oxidation ◽  
Photocatalytic Properties ◽  
Top Down ◽  
Ion Exchange Reaction

BiVO4 is one of the fascinating materials with excellent photocatalytic properties. A top-down approach composed of solid state reaction and ion exchange reaction is introduced to fabricate Ti doped BiVO4...

Fabrication of magnetic BaFe12O19/Ag3PO4 composites with an in situ photo-Fenton-like reaction for enhancing reactive oxygen species under visible light irradiation

2019 ◽  
Vol 9 (10) ◽  
pp. 2563-2570 ◽  
Author(s):  
Yuanguo Xu ◽  
Feiyue Ge ◽  
Meng Xie ◽  
Shuquan Huang ◽  
Junchao Qian ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Reactive Oxygen ◽  
Light Irradiation ◽  
Oh Radicals ◽  
Oxygen Species

An in situ photo-Fenton-like and magnetic recycle system, BaFe12O19/Ag3PO4 has been constructed. BaFe12O19 can catalyze the conversion of H2O2 to generate ROSs (˙O2− and ˙OH radicals) on the surface of Ag3PO4.

Mechanism of CeVO4/TiO2 Photocatalytic Degradation of VOCs under Visible Light Irradiation: Electrochemical, Photoluminescence and Active Oxygen Species Study

2012 ◽  
Vol 217-219 ◽  
pp. 853-856 ◽  
Author(s):  
Han Jie Huang ◽  
Wen Long She ◽  
Ling Wen Yang
Keyword(s):  
Reactive Oxygen Species ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Gas Phase ◽  
Degradation Mechanism ◽  
Active Oxygen Species ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Composite Photocatalyst ◽  
Photocatalytic Degradation Mechanism

In this paper, CeVO4/TiO2 composite photocatalyst has been characterized by photoelectrochemical and reactive oxygen species trap techniques to reveal the mechanism for photocatalytic degradation of VOCs in gas-phase. Based on the measurement of flatband of the samples and the detection of reactive oxygen species, a visible light-induced photocatalytic degradation mechanism of VOCs on CeVO4/TiO2 is proposed.

Visible light driven mesoporous Ag-embedded ZnO nanocomposites: reactive oxygen species enhanced photocatalysis, bacterial inhibition and photodynamic therapy

2017 ◽  
Vol 46 (3) ◽  
pp. 685-696 ◽  
Author(s):  
Jagriti Gupta ◽  
Jeotikanta Mohapatra ◽  
D. Bahadur
Keyword(s):  
Reactive Oxygen Species ◽  
Photodynamic Therapy ◽  
Visible Light ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Bacterial Inhibition ◽  
Visible Light Driven

The systemic diagram shows the mechanism of photocatalysis, bacterial inhibition and photodynamic therapy through the generation of reactive oxygen species.

Production of Reactive Oxygen Species from Photosensitizers Activated with Visible Light Sources Available in Dental Offices

2010 ◽  
Vol 28 (4) ◽  
pp. 519-525 ◽  
Author(s):  
Serge Bouillaguet ◽  
John C. Wataha ◽  
Oscar Zapata ◽  
Marino Campo ◽  
Norbert Lange ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Visible Light ◽  
Reactive Oxygen ◽  
Light Sources ◽  
Oxygen Species ◽  
Dental Offices
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