106070-31-9Relevant articles and documents
Pyrocatalytic oxidation-strong size-dependent poling effect on catalytic activity of pyroelectric BaTiO3nano- And microparticles
Braeutigam, Patrick,Buchheim, Johannes R.,Neumeister, Peter,Raufeisen, Sascha,Stelter, Michael
, p. 23464 - 23473 (2020)
Pyrocatalysis is an emerging advanced oxidation process for wastewater remediation with the potential for thermal energy harvesting and utilization. Although several studies explored the potential of new pyrocatalyst materials to degrade harmful organic water pollutants, the role of important material properties and electric poling procedures on the pyrocatalytic activity is still unclear. In this work, we investigate the interdependence between particle size, electric poling and pyrocatalytic activity of BaTiO3 powders with nominal particle sizes of 100, 200 and 500 nm by using the dichlorofluorescein redox assay. Depending on the particle size, the influence of surface area or phase composition on the pyrocatalytic activity predominates. Moreover, we demonstrate that poling of pyrocatalysts leads to a strong size-dependent increase of pyrocatalytic activity. This poling effect increases with particle size up to +247% and can be explained with size-dependent changes in phase composition and domain structure. Combining all results, the progression of the pyrocatalytic activity as a function of particle size was derived and a future strategy for maximizing the catalytic performance of pyrocatalysts was developed. This study greatly improves the understanding about the role of important material properties and electric poling on pyrocatalytic activity, thus enabling an effective catalyst design. With the help of highly active catalysts, the pyrocatalytic process can take the next step in its development into a new and energy-efficient advanced oxidation process for water remediation.
Melatonin enhances photo-oxidation of 29, 79-dichlorodihydrofluorescein by an antioxidant reaction that renders N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK)
Hevia, David,Mayo, Juan C.,Tan, Dun-Xian,Rodriguez-Garcia, Aida,Sainz, Rosa M.
, (2014)
The indolamine melatonin (MEL) is described as an antioxidant and a free radical scavenger. However occasionally, the indoleamine has been reported to increase free radicals with insufficient mechanistic explanation. In an attempt to find a reason for tho
Active oxygen chemistry within the liposomal bilayer: Part IV: Locating 2′,7′-dichlorofluorescein (DCF), 2′,7′- dichlorodihydrofluorescein (DCFH) and 2′,7′- dichlorodihydrofluorescein diacetate (DCFH-DA) in the lipid bilayer
Afri, Michal,Frimer, Aryeh A.,Cohen, Yael
, p. 123 - 133 (2004)
2′,7′-Dichlorodihydrofluorescein diacetate (DCFH-DA) is commonly used to detect the generation of reactive oxygen intermediates and for assessing the overall oxidative stress in toxicological phenomenon. It has been suggested that DCFH-DA crosses the cell
Ultrasound-dependent cytoplasmic internalization of a peptide-sonosensitizer conjugate
Inaba, Yuki,Watanabe, Kazunori,Kitamatsu, Mizuki,Nakata, Eiji,Harada, Atsushi,Ohtsuki, Takashi
, p. 4212 - 4217 (2017)
A method to induce cytoplasmic peptide delivery, using ultrasound, was demonstrated using a molecular conjugate of a cell-penetrating peptide (CPP), a functional peptide, and a sonosensitizer. As a model of such molecular conjugates, TatBim-RB, consisting
Identification of ros produced by photodynamic activity of chlorophyll/cyclodextrin inclusion complexes
Cellamare, Barbara M.,Fini, Paola,Agostiano, Angela,Sortino, Salvatore,Cosma, Pinalysa
, p. 432 - 441 (2013)
Photodynamic therapy (PDT) is a way of treating malignant tumors and hyperproliferative diseases. It is based on the use of photosensitizer, herein the chlorophyll a (chl a), and a light of an appropriate wavelength. The interaction of the photosensitizer (PS) with the light produces reactive oxygen species (ROS), powerful oxidizing agents, which cause critical damage to the tissue. To solubilize chl a in aqueous solution and to obtain it as monomer, we have used cyclodextrins, carriers which are able to interact with the pigment and form the inclusion complex. The aim of this study is to examine which types of ROS are formed by Chl a/cyclodextrin complexes in phosphate buffered solution and cell culture medium, using specific molecules, called primary acceptors, which react selectively with the reactive species. In fact the changes of the absorption and the emission spectra of these molecules after the illumination of the PS provide information on the specific ROS formation. The 1O2 formation has been tested using chemical methods based on the use of Uric Acid (UA), 9,10-diphenilanthracene (DPA) and Singlet oxygen sensor green (SOSG) and by direct detection of Singlet Oxygen ( 1O2) luminescence decay at 1270 nm. Moreover, 2,7-dichlorofluorescin and ferricytochrome c (Cyt Fe3+) have been used to detect the formation of hydrogen peroxide and superoxide radical anion, which reduces Fe3+ of the ferricytochrome to Fe2+, respectively. For the first time, photodynamic activity in vitro of natural Chlorophyll a (Chl a) has been investigated evidencing which types of ROS are formed. Chl a has been solubilized in aqueous solution by means of various cyclodextrins forming inclusion complexes. The ROS production has been carried out in the system using specific molecules, called primary acceptors, which react selectively with the reactive species.
Easy access of dihydrofluoresceins as advanced fluorescence turn-on probes for oxidative stress
Deng, Tao,Bao, Huayu,Huang, Wenyi,Wang, Xiaojuan,Hu, Shiyou,Wu, Shengjun,Zhao, Liang,Cai, Chun,Hu, Yingjie,Liu, Fang
, (2020)
A mild NABH4/I2 strategy was designed to easily reduce fluoresceins to dihydrofluorescein alcohols and acids. Dihydrofluorescein alcohols exhibited surprisingly enhanced reactivity for oxidative stress sensing in comparison with the
Singlet oxygen reacts with 2′,7′-dichlorodihydrofluorescein and contributes to the formation of 2′,7′-dichlorofluorescein
Daghastanli, Nasser A.,Itri, Rosangela,Baptista, Mauricio S.
, p. 1238 - 1243 (2008)
There are controversial reports in the literature concerning the reactivity of singlet oxygen (1O2) with the redox probe 2′,7′-dichlorodihydrofluorescein (DCFH). By carefully preparing solutions in which 1O2 is quantitatively generated in the presence of DCFH, we were able to show that the formation rate of the fluorescent molecule derived from DCFH oxidation, which is 2′,7′- dichlorofluorescein (DCF), increases in D2O and decreases in sodium azide, proving the direct role of 1O2 in this process. We have also prepared solutions in which either 1O2 or dication (MB?2+) and semi-reduced (MB?) radicals of the sensitizer and subsequently super-oxide radical (O2 ?-) are generated. The absence of any effect of SOD and catalase ruled out the DCFH oxidation by O2?-, indicating that both 1O2 and MB?2+ react with DCFH. Although the formation of DCF was 1 order of magnitude larger in the presence of MB?2+ than in the presence of 1O2, considering the rate of spontaneous decays of these species in aqueous solution, we were able to conclude that the reactivity of 1O2 with DCFH is actually larger than that of MB?2+. We conclude that DCFH can continue to be used as a probe to monitor general redox misbalance induced in biologic systems by oxidizing radicals and 1O2.
