Read by QxMD icon Read

metal nanoparticle

Sureshkumar Kempahanumakkagari, Akash Deep, Ki-Hyun Kim, Suresh Kumar Kailasa, Hye-On Yoon
The existence of arsenic in the environment poses severe global health threats. Considering its toxicity, the sensing of arsenic is extremely important. Due to the complexity of environmental and biological samples, many of the available detection methods for arsenic have serious limitations on selectivity and sensitivity. To improve sensitivity and selectivity and to circumvent interferences, different electrode systems have been developed based on surface modification with nanomaterials including carbonaceous nanomaterials, metallic nanoparticles (MNPs), metal nanotubes (MNTs), and even enzymes...
April 13, 2017: Biosensors & Bioelectronics
Chang Lu, Zhicheng Huang, Biwu Liu, Yibo Liu, Yibin Ying, Juewen Liu
Attaching DNA to nanomaterials is the basis for DNA-directed assembly, sensing, and drug delivery using such hybrid materials. Poly-cytosine (poly-C) DNA is a high affinity ligand for four types of commonly used nanomaterials, including nanocarbons (graphene oxide and single-walled carbon nanotubes), transition metal dichalcogenides (MoS2 and WS2 ), metal oxides (Fe3 O4 and ZnO), and metal nanoparticles (Au and Ag). Compared to other homo-DNA sequences, poly-C DNA has the highest affinity for the first three types of materials...
April 21, 2017: Angewandte Chemie
Debabrata Sikdar, Alwin Bucher, Cristian Zagar, Alexei A Kornyshev
Self-assembling arrays of metallic nanoparticles at liquid|liquid or liquid|solid interfaces could deliver new platforms for tuneable optical systems. Such systems can switch between very-high and very-low reflectance states upon assembly and disassembly of nanoparticles at the interface, respectively. This encourages creation of electro-variably reversible mirror/window nanoplasmonic devices. However, the response time of these systems is usually limited by the rate-of-diffusion of the nanoparticles in the liquid, towards the interface and back...
April 21, 2017: Faraday Discussions
A Mukherjee, A D Craciun, J L Gallani, M V Rastei
We present experimental and theoretical results on controlling nanoscale sliding friction and adhesion by electric fields on model contacts realized by bringing a conductive atomic force microscope tip into contact with the surface of a silicon-oxide/silicon wafer. We find that applying a bias voltage on silicon (or on the conductive tip) enables a noticeable control of the sliding forces. Two electrostatic interactions are identified as being relevant for the friction variation as a function of applied voltage...
April 21, 2017: Faraday Discussions
Xin Gao, Xiangxuan Liu, Zuoming Zhu, Ying Gao, Qingbo Wang, Fei Zhu, Zheng Xie
In this paper, we propose a nanostructure with Au nanoparticles (NPs), as electron sinks, located at the most outside layer of CdS sensitized TiO2 nanorod arrays (TiO2 NRAs/CdS/Au). By the introduction of Au NPs, TiO2 NRAs/CdS/Au performs higher visible light photocatalytic capacity in the degradation of unsymmetrical dimethylhydrazine wastewater than TiO2 NRAs/CdS. The optimal deposition time for Au NPs is 30 s. The visible light induced degradation ability of TiO2 NRAs/CdS/Au (30 s) is 1.4 times that of TiO2 NRAs/CdS...
April 20, 2017: Scientific Reports
Yugang Sun, Xiaobing Zuo, Subramanian K R S Sankaranarayanan, Sheng Peng, Badri Narayanan, Ganesh Kamath
Real-time tracking of the three-dimensional (3D) evolution of colloidal nanoparticles in solution is essential for understanding complex mechanisms involved in nanoparticle growth and transformation. We used time-resolved small-angle and wide-angle x-ray scattering simultaneously to monitor oxidation of highly uniform colloidal iron nanoparticles, enabling the reconstruction of intermediate 3D morphologies of the nanoparticles with a spatial resolution of ~5 angstroms. The in situ observations, combined with large-scale reactive molecular dynamics simulations, reveal the details of the transformation from solid metal nanoparticles to hollow metal oxide nanoshells via a nanoscale Kirkendall process-for example, coalescence of voids as they grow and reversal of mass diffusion direction depending on crystallinity...
April 21, 2017: Science
Payam Abdolalian, Ali Morsali, Giuseppe Bruno
Micro and nano-structures of a new mixed-ligand Zn(II) fumarate metal-organic polymer, {[Zn(tptz)(fum)].DMF}n (1), (tptz=2,4,6-tris(2-pyridyl)-s-triazine, fum=fumarate, DMF=N,N-dimethylforamide), were synthesized by sonochemical method. These new micro and nano-structures were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), IR spectroscopy and elemental analyses. Compound 1 was structurally characterized by single-crystal X-ray diffraction and consists of the primary unit of [Zn(tptz)(fum)]...
July 2017: Ultrasonics Sonochemistry
Xiao-Xue Cheng, Shiva Hojaghani, Mao-Lin Hu, Moayed Hosaini Sadr, Ali Morsali
Nanostructures of three new cobalt(II) complexes, (CoL1)·0.5DMF·1.5MeOH (1), [H2L1=5-(4-Carboxy phenyl azo) anthranilic acid], (Co(L2)2)·1.5MeOH (2), [HL2=5-(4-Carboxy phenyl azo) salicylaldehyde] and (Co(L3)2)·0.5DMF·0.5MeOH (3), [HL3=1-(4-Carboxy phenyl azo) 2-naphtol], have been synthesized by the reaction of H2L1, HL2 and HL3 with Co(OAc)2·4H2O through sonochemical process. Calcination of the nano-sized compounds 1-3 yield Co3O4 nanoparticles at 450°C under air atmosphere. These nanostructures were characterized by X-ray powder diffraction (XRD) and Scanning Electron Microscopy (SEM)...
July 2017: Ultrasonics Sonochemistry
Younes Hanifehpour, Ali Morsali, Babak Mirtamizdoust, Sang Woo Joo, Behzad Soltani
Nano-structures of a new supramolecular coordination compound of divalent nickel with the pyrazol (pzH) containing the terminal azide anions, [Ni(pzH)2(N3)2] (1), with discrete molecular architecture (DMA) in solid state was synthesized via sonochemical method. The new nanostructure was characterized by scanning electron microscopy, X-ray powder diffraction, IR, and elemental analysis. Compound 1 was structurally characterized by single crystal X-ray diffraction and the single-crystal X-ray data shows that the coordination number of Ni (II) ions is six, (NiN6), with four N-donor atoms from neutral "pzH" ligands and two N-donors from two terminal azide anions...
July 2017: Ultrasonics Sonochemistry
Fahime Bigdeli, Hosein Ghasempour, Alireza Azhdari Tehrani, Ali Morsali, Hassan Hosseini-Monfared
A 3D, porous Zn(II)-based metal-organic framework {[Zn2(oba)2(4-bpmn)]·(DMF)1.5}n (TMU-21), (4-bpmn=N,N'-Bis-pyridin-4-ylmethylene-naphtalene-1,5-diamine, H2oba=4,4'-oxybis(benzoic acid)) with nano-rods morphology under ultrasonic irradiation at ambient temperature and atmospheric pressure was prepared and characterized by scanning electron microscopy. Sonication time and concentration of initial reagents effects on the size and morphology of nano-structured MOFs were studied. Also {[Zn2(oba)2(4-bpmn)] (TMU-21) and {[Zn2(oba)2(4-bpmb)] (TMU-6), 4-bpmb=N,N'-(1,4-phenylene)bis(1-(pyridin-4-yl)methanimine) were easily prepared by mechanochemical synthesis...
July 2017: Ultrasonics Sonochemistry
Amir Reza Abbasi, Maryam Karimi, Kim Daasbjerg
The present investigation reports the synthesis of CuBTC (BTC=1,3,5-benzenetricarboxylate) metal-organic frameworks (MOFs) under solid-state conditions and ultrasound irradiation. Herein, we study uptake and release properties of crystal violet (CV) and methylene blue (MB) from ultrasound nano-CuBTC MOF in comparison with mechanosynthesis method (bulk structure). The ultrasound-assisted methods give a decrease in the surface area as calculated from the reduced nitrogen adsorption capability. In comparison, the uptake of guest molecules on ultrasound nano-CuBTC is remarkable and clearly exceeds that of bulk structure in the aqueous solution of guests...
July 2017: Ultrasonics Sonochemistry
Andrea E Schlather, Alejandro Manjavacas, Adam Lauchner, Valeria Spolon Marangoni, Christopher J DeSantis, Peter Nordlander, Naomi J Halas
There is currently a worldwide need to develop efficient photocatalytic materials that can reduce the high energy cost of common industrial chemical processes. One possible solution focuses on metallic nanoparticles (NPs) that can act as efficient absorbers of light due to their surface plasmon resonance. Recent work indicates that small NPs, when photoexcited, may allow for efficient electron or hole transfer necessary for photocatalysis. Here we investigate the mechanisms behind hot hole carrier dynamics by studying the photo-driven oxidation of citrate ions on Au@SiO2@Au core-shell nanoparticles...
April 20, 2017: Journal of Physical Chemistry Letters
Jan Klouda, Jiří Barek, Karel Nesměrák, Karolina Schwarzová-Pecková
This review summarizes achievements in electrochemistry-related research of steroid-based compounds in clinical, pharmaceutical, and environmental analysis. Special attention is paid to compounds possessing none or only isolated double bonds at the steroid core. Their direct redox activity is limited to far positive/negative potentials under variety of conditions and electrode materials and relies on the functional groups attached to the steroid skeleton, or as the case may be its double bond, or moieties present at the side chain...
April 20, 2017: Critical Reviews in Analytical Chemistry
Wei Ma, Liguang Xu, André F de Moura, Xiaoling Wu, Hua Kuang, Chuanlai Xu, Nicholas A Kotov
The field of chiral inorganic nanostructures is rapidly expanding. It started from the observation of strong circular dichroism during the synthesis of simple nanoparticles (NPs) and their assemblies mediated by biomolecules and expanded to sophisticated synthetic protocols involving nanostructures from metals, semiconductors, ceramics, and nanocarbons. Besides the well-established chirality transfer from bioorganic molecules, other methods to impart handedness to nanoscale matter specific to inorganic materials were discovered, including three-dimentional lithography, multiphoton chirality transfer, polarization effects in nanoscale assemblies, and others...
April 20, 2017: Chemical Reviews
Ajay Shankar, Alexander P Safronov, Ekaterina A Mikhnevich, Igor V Beketov, Galina V Kurlyandskaya
A new kind of ferrogel with entrapped metallic iron nanoparticles causing unusual magnetodeformation is presented. Crosslinked polyacrylamide (PAAm) based ferrogels embedded with iron nanoparticles (MNPs) were synthesized by free radical polymerization in aqueous medium. Spherical iron MNPs with average diameter 66 nm were synthesized by the electrical explosion of wire and modified by interfacial adsorption of linear polyacrylamide (LPAAm). Extended Derjaguin-Landau-Verwey-Overbeek (xDLVO) calculations based on the superposing of van der Waals, electrostatic, steric, and magnetic contributions showed that polymeric encapsulation of nanoparticles by LPAAm is one of the most suitable pathways for preparing stable aqueous dispersions of iron nanoparticles...
April 20, 2017: Soft Matter
A Le Beulze, S Gomez-Graña, H Gehan, S Mornet, S Ravaine, M Correa-Duarte, L Guerrini, R A Alvarez-Puebla, E Duguet, E Pertreux, A Crut, P Maioli, F Vallée, N Del Fatti, O Ersen, M Treguer-Delapierre
Raspberry-like nano-objects made of large plasmonic satellites (>10 nm) covering a central dielectric particle have many potential applications as photonic materials, superlenses and (bio-) sensors, but their synthesis remains challenging. Herein, we show how to build stable and robust raspberry-like nano-systems with close-packed satellites, by combining monodisperse silica particles (80 or 100 nm diameter) and oppositely charged noble metal nanoparticles (Au or Ag) with well-defined sizes (10-50 nm). The spectral characteristics of their associated plasmonic resonances (wavelength, linewidth, extinction cross-section) and the electromagnetic coupling between satellites were observed using the spatial modulation spectroscopy technique and interpreted through a numerical model...
April 20, 2017: Nanoscale
Wan Li, Shilin Zhang, Qining Fan, Fazhi Zhang, Sailong Xu
Transition metal phosphide (TMP) nanostructures have stimulated increasing interest for use in water splitting owing to their abundant natural sources and high activity for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Typically, the preparation of hierarchical TMPs involves the utilization of expensive or dangerous phosphorus sources, and, in particular, the understanding of topotactic transformations of the precursors to crystalline phases-which could be utilized to enhance electrocatalytic performance-remains very limited...
April 20, 2017: Nanoscale
Haiying He, Yesukhei Jagvaral
In this study, we have investigated the use of single metal atoms supported on defective graphene as catalysts for the electrochemical reduction of CO2 using the first-principles approach and the computational hydrogen electrode model. Reaction pathways to produce a variety of C1 products CO, HCOOH, HCHO, CH3OH and CH4 have been studied in detail for five representative transition metals Ag, Cu, Pd, Pt, and Co. Different pathways were revealed in contrast to those found for metallic crystalline surfaces and nanoparticles...
April 20, 2017: Physical Chemistry Chemical Physics: PCCP
Xiaoyu Wu, Songmei Li, Bo Wang, Jianhua Liu, Mei Yu
Transition-metal sulfide hollow nanostructures have received intensive attention in energy-related applications due to their unique structural features and high electrochemical activities. Here, a well-designed composite of NiCo2S4@C is successfully fabricated using a facile in situ template removal method. The obtained composite shows unique microstructures of hollow nanospheres (∼650 nm in diameter) assembled from ultrathin NiCo2S4@C nanosheets, in which numerous scattered NiCo2S4 nanoparticles are embedded in ultrathin carbon nanosheets, exhibiting mesoporous features with a high surface area of 247...
April 20, 2017: Physical Chemistry Chemical Physics: PCCP
Markéta Prusková, Veronika Sutrová, Miroslav Šlouf, Blanka Vlčková, Jiří Vohlídal, Ivana Šloufová
The assembly of Ag and Au nanoparticles (NPs) into nanoparticulate arrays mediated by terpyridine (tpy), 4'-(2-thienyl)terpyridine (T-tpy), and short α,ω-bis(tpy)oligothiophene ligands has been accomplished at the interface between the Ag or Au NP hydrosol and a solution of the molecular species in dichloromethane. The relationship between the morphology and the optical responses of the arrays has been investigated by advanced methods of TEM (transmission electron microscopy) image analysis and surface plasmon extinction (SPE) spectra...
April 19, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"