Search results for "Metal nanoparticle"
showing 10 items of 175 documents
Design of cost-efficient and photocatalytically active Zn-based MOFs decorated with Cu 2 O nanoparticles for CO 2 methanation
2019
<div>Here we show for the first time a MOF that is photocatalytically</div><div>active for the light-assisted CO<sub>2</sub> methanation at mild conditions</div><div>(215 °C) without the inclusion of metallic nanoparticles or any</div><div>sacrificial agent. The presence of Cu<sub>2</sub>O nanoparticles causes a 50 % increase in the photocatalytic activity. These results pave the way to developping efficient and cost-effective materials for CO<sub>2</sub> elimination.</div>
Growth of glass-embedded Cu nanoparticles: A low-frequency Raman scattering study
2012
International audience; Several populations of Cu spherical nanoparticles grown in a silicate glass at different temperatures with respect to the glass transition temperature were studied using high-resolution, low-frequency Raman scattering and optical absorption. The analysis of the spectra shows that the annealing of the doped glass at temperatures close to T-g leads to the formation of metallic copper nanoparticles with high crystallinity, whereas lower-temperature and higher-temperature annealings result in the formation of poorer nanoparticle assemblies in terms of size distribution and/or nanocrystallinity. It is also shown that in the case where the optical data do not unambiguously…
Resistance to Nano-Based Antifungals Is Mediated by Biomolecule Coronas.
2018
Fungal infections are a growing global health and agricultural threat, and current chemical antifungals may induce various side-effects. Thus, nanoparticles are investigated as potential novel antifungals. We report that nanoparticles' antifungal activity strongly depends on their binding to fungal spores, focusing on the clinically important fungal pathogen Aspergillus fumigatus as well as common plant pathogens, such as Botrytis cinerea. We show that nanoparticle-spore complex formation was enhanced by the small nanoparticle size rather than the material, shape or charge, and could not be prevented by steric surface modifications. Fungal resistance to metal-based nanoparticles, such as Zn…
Co-crystallization of atomically precise metal nanoparticles driven by magic atomic and electronic shells
2018
This paper reports co-crystallization of two atomically precise, different-size ligand-stabilized nanoclusters, a spherical (AuAg)267(SR)80 and a smaller trigonal-prismatic (AuAg)45(SR)27(PPh3)6 in 1:1 ratio, characterized fully by X-ray crystallographic analysis (SR = 2,4-SPhMe2). The larger cluster has a four concentric-shell icosahedral structure of Ag@M12@M42@M92@Ag120(SR)80 (M = Au or Ag) with the inner-core M147 icosahedron observed here for metal nanoparticles. The cluster has an open electron shell of 187 delocalized electrons, fully metallic, plasmonic behavior, and a zero HOMO-LUMO energy gap. The smaller cluster has an 18-electron shell closing, a notable HOMO-LUMO energy gap and…
Halloysite nanotubes as support for metal-based catalysts
2017
Halloysite nanotubes (HNTs) are clay minerals with a hollow nanotubular structure. There is growing interest in these nanomaterials, due to their biocompatibility, potential applications and availability. The surface chemistry of HNTs is versatile for the targeted chemical modification of the inner lumen and outer surface. Functionalized halloysite constitutes a valuable support for metal nanoparticles, promoting catalytic applications with tunable properties. The peculiar tubular shape of HNTs favors the dispersion and surface availability of the supported metal nanoparticles that are active in the catalytic path. Moreover, the presence of an empty lumen opens new perspectives for the prod…
Innovations in Extractive Phases for In-Tube Solid-Phase Microextraction Coupled to Miniaturized Liquid Chromatography: A Critical Review
2020
Over the past years, a great effort has been devoted to the development of new sorbents that can be used to pack or to coat extractive capillaries for in-tube solid-phase microextraction (IT-SPME). Many of those efforts have been focused on the preparation of capillaries for miniaturized liquid chromatography (LC) due to the reduced availability of capillary columns with appropriate dimensions for this kind of system. Moreover, many of the extractive capillaries that have been used for IT-SPME so far are segments of open columns from the gas chromatography (GC) field, but the phase nature and dimensions are very limited. In particular, polar compounds barely interact with stationary GC phas…
Plasmonic Nanosensors for the Label-Free Imaging of Dynamic Protein Patterns.
2020
We introduce a new approach to monitor the dynamics and spatial patterns of biological molecular assemblies. Our molecular imaging method relies on plasmonic gold nanoparticles as point-like detectors and requires no labeling of the molecules. We show spatial resolution of up to 5 μm and 30 ms temporal resolution, which is comparable to wide-field fluorescence microscopy, while requiring only readily available gold nanoparticles and a dark-field optical microscope. We demonstrate the method on MinDE proteins attaching to and detaching from lipid membranes of different composition for 24 h. We foresee our new imaging method as an indispensable tool in advanced molecular biology and biophysic…
Genotoxic effects of zinc oxide nanoparticles
2015
The potential toxicity of nanoparticles has currently provoked public and scientific discussions, and attempts to develop generally accepted handling procedures for nanoparticles are under way. The investigation of the impact of nanoparticles on human health is overdue and reliable test systems accounting for the special properties of nanomaterials must be developed. Nanoparticular zinc oxide (ZnO) may be internalised through ambient air or the topical application of cosmetics, only to name a few, with unpredictable health effects. Therefore, we analysed the determinants of ZnO nanoparticle (NP) genotoxicity. ZnO NPs (15-18 nm in diameter) were investigated at concentrations of 0.1, 10 and …
Titanate nanotubes: towards a novel and safer nanovector for cardiomyocytes.
2012
Actively contractile cardiomyocyte (CM) monolayer represents an interesting tool to study both cardiac diseases and injuries. However, this model is poorly transfectable with conventional agents. Consequently, there is a need to develop new carriers that could overcome this problem. Titanate nanotubes (TiONts) could be a potential candidate due to possibly higher cell uptake as a direct consequence of their shape. On the basis of this rationale, TiONts were assessed for their cytotoxicity and internalization pathways. Cytotoxicity was assessed for TiONts either functionalized with PEI or unfunctionalized and its spherical counterpart P25 TiO2. No cytotoxic effect was observed under TiONts, …
Cytotoxicity of Metal and Semiconductor Nanoparticles Indicated by Cellular Micromotility
2009
In the growing field of nanotechnology, there is an urgent need to sensitively determine the toxicity of nanoparticles since many technical and medical applications are based on controlled exposure to particles, that is, as contrast agents or for drug delivery. Before the in vivo implementation, in vitro cell experiments are required to achieve a detailed knowledge of toxicity and biodegradation as a function of the nanoparticles' physical and chemical properties. In this study, we show that the micromotility of animal cells as monitored by electrical cell-substrate impedance analysis (ECIS) is highly suitable to quantify in vitro cytotoxicity of semiconductor quantum dots and gold nanorods…