21 Apr 22:32
by Yanyan Huang, Zhen Liu, Chaoqun Liu, Enguo Ju, Yan Zhang, Jinsong Ren, Xiaogang Qu
Abstract
In this work, for the first time, we constructed a novel multi-nanozymes cooperative platform to mimic intracellular antioxidant enzyme-based defense system. V2O5 nanowire served as a glutathione peroxidase (GPx) mimic while MnO2 nanoparticle was used to mimic superoxide dismutase (SOD) and catalase (CAT). Dopamine was used as a linker to achieve the assembling of the nanomaterials. The obtained V2O5@pDA@MnO2 nanocomposite could serve as one multi-nanozyme model to mimic intracellular antioxidant enzyme-based defense procedure in which, for example SOD, CAT, and GPx co-participate. In addition, through assembling with dopamine, the hybrid nanocomposites provided synergistic antioxidative effect. Importantly, both in vitro and in vivo experiments demonstrated that our biocompatible system exhibited excellent intracellular reactive oxygen species (ROS) removal ability to protect cell components against oxidative stress, showing its potential application in inflammation therapy.
Artificial enzyme complexes: A multi-nanozyme cooperative platform was constructed to mimic an intracellular antioxidant enzyme-based defense system and protect cells against oxidative stress (see picture). This development holds great promise for potential applications in cancer and inflammation therapy.
liuzhi and -1 others like this
14 Nov 21:45
Publication date: February 2015
Source:Sensors and Actuators B: Chemical, Volume 207, Part A
Author(s): Shurong Wang , Jiedi Yang , Hongxin Zhang , Yanshuang Wang , Xueling Gao , Liwei Wang , Zhenyu Zhu
3D hierarchical SnO2 nanostructures, constructed by well-defined 1D SnO2 nanorod units, were synthesized by a facile, one-step hydrothermal route, only using simple inorganic compounds SnCl4·5H2O and NaOH as starting materials, without using any surfactants and templates. The prepared 3D SnO2 hierarchical nanostructures were applied to fabricate a gas sensor for selectively detecting n-butanol. The gas sensing results demonstrated that the 3D SnO2 hierarchical nanostructure sensor exhibited excellent gas sensing performances to ppm-level n-butanol in terms of high response, good reproducibility, fast response–recovery characteristics and superior selectivity, and significantly enhanced response compared with the commercial SnO2 nanopowder sensor. The enhanced gas sensing performances could be attributed to the facilitated molecular absorption, gas diffusion and mass transport induced by the unique 3D loose and porous structure, and the high surface-to-volume ratio resulted from the 1D rod-like nanostructure which could provide more active sites for gas absorption. It was believed that the 3D hierarchical SnO2 nanostructures could also further offer a potential opportunity for other applications such as lithium-ion batteries, catalysis and dye-sensitized solar cells.
02 Apr 13:27
by Elise Bernoud, Pascal Oulié, Régis Guillot, Mohamed Mellah, Jérôme Hannedouche
Abstract
Despite the growing interest in iron catalysis and hydroamination reactions, iron-catalyzed hydroamination of unprotected primary aliphatic amines and unactivated alkenes has not been reported to date. Herein, a novel well-defined four-coordinate β-diketiminatoiron(II) alkyl complex is shown to be an excellent precatalyst for the highly selective cyclohydroamination of primary aliphatic alkenylamines at mild temperatures (70–90 °C). Both empirical kinetic analyses and the reactivity of an isolated iron(II) amidoalkene dimer, [LFe(NHCH2CPh2CH2CH![[DOUBLE BOND]](http://onlinelibrarystatic.wiley.com/undisplayable_characters/00f8fe.gif)
CH2)]2 favor a stepwise σ-insertive mechanism that entails migratory insertion of the pendant alkene into an iron–amido bond associated with a rate-determining aminolysis step.
Iron horseshoe: A well-defined four-coordinate β-diketiminatoiron(II) alkyl complex is a precatalyst for the highly selective cyclohydroamination of primary aliphatic alkenylamines at mild temperatures. Its mechanism is also elucidated.
Open Access
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