Polyacrylonitrile/Nafion®/carbon nanotube (PAN/Nafion®/CNT) composite nanofibers were prepared using electrospinning. These electrospun nanofibers were studied as possible substrates for surface-assisted laser desorption/ionization (SALDI) and matrix-enhanced surface-assisted laser desorption/ionization time
In this paper, we report on the functionalization of silicon nanostructured (NanoSi) surface with an organic layer of nitrilotriacetic acid (NTA) and its subsequent use as an affinity surface-assisted laser desorption/ionization mass spectrometry (SA
TY - JOUR. T1 - Magneto-optical properties and size effect of ferromagnetic metal nanoparticles. AU - Kaihara, Terunori. AU - Mizuguchi, Masaki. AU - Takanashi, Koki. AU - Shimizu, Hiromasa. PY - 2013/1/1. Y1 - 2013/1/1. N2 - We investigated the magneto-optical (MO) effect with localized surface plasmon resonance (LSPR) on ferromagnetic metal (Fe and Co) nanoparticles. We estimated the electric-field enhancement of the ferromagnetic metal nanoparticles caused by LSPR based on Mie scattering theory and compared it with that of Au nanoparticles. The electric-field enhancement of the ferromagnetic metal nanoparticles was 15-17, which is half of that of the Au nanoparticles. In order to explain the calculated results, we prepared ferromagnetic metal nanoparticles by a self-assembly process. We measured the optical transmission spectra and Faraday effect of the ferromagnetic nanoparticles. Although remarkable MO enhancement was not observed, we found characteristic MO spectra and a peak shift at ...
The recent progress in the area of science and technology is the emergence of nanotechnology, and that having its role in all disciplinary field. In the nanotechnology, green way of metal nanoparticles synthesis plays an essential role nowadays. The advantages of using plant extract in the metal nanoparticles synthesis is less toxic, economic, environmentally friendly. The involvement of metal nanoparticles in the management of various chronic non-communicable diseases leads to the cause for new field Nano medicine. The management for various serious diseases without any side effect is the ultimate aim of all researchers in the scientific field with the help of nanomaterials and nanostructures. Diabetes mellitus kills most of the population next to cancer worldwide, in India diabetes mellitus death rate is going to be expected in the first place by 2045 by WHO. Though various medicinal plants were used for the curative application of diabetes mellitus, the nanotechnology gives insights into the research
The synthesis of noble metal nanoparticles (i.e., silver and gold) for electrochemical applications has been widely studied using mainly wet synthesis chem
download from bioimaging to biosensors noble metal nanoparticles CELL DISEASE AFFECTS PHYSICAL GROWTHR. PANCHALI TARAFDER, KAUSHIK SARKAR, PARTHA P. COMPRISING OF PSEUDOMONAS AND PAENIBACILLUS CELLS, ON THE neighborhood OF properties. audience AND nativity OF DIFFERENT FORMULATIONS OF PSEUDOMONAS FLUORESCENS number FOR THE aut OF PLANT GROWTH AND INDUCTION OF SYSTEMIC RESISTANCE AGAINST PYRICULARIA ORYZAE IN LOWLAND RICEP.
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The understanding of the desorption mechanism in surface-assisted laser desorption/ionization (SALDI) remains incomplete because there are numerous types o
Article Electron-phonon coupling and heat dissipation in metal nanoparticles. This review discusses electron-phonon (e-ph) coupling and heat dissipation in noble metal nanoparticles, specifically, how the time constants for these events depend on siz...
Abstract. Catalysts are crucial for the production of fuels, chemicals and materials and for energy storage and conversion. They often consist of transition metal nanoparticles (,10 nm) as an active phase, supported on a porous material that provides stability to the system, but has 3D open porosity to allow diffusion of reactants and products. The effectiveness of a catalyst is a combination of three qualities: activity, selectivity and stability. All three are not only determined by the composition of the metal nanoparticle, but also greatly depend on factors such as the exact particle size (and particle size distribution), a redistribution of atoms within the nanoparticle under reaction conditions, the interaction between the metal nanoparticle and the support, and small amounts of additives (promoters) which can modify for instance the electronic properties or provide specific sites.. We study the performance of supported metal nanoparticles using 3D model supports (ordered mesoporous ...
A composite with well-dispersed metal nanoparticles at a ceramic surface was produced by partial reduction of solid solution. It was found that a small amount of dopant, such as Al2O3, Cr2O3, or Sc2O3, accelerated the precipitation of the metal nanoparticles during the reduction. Catalytic performance of the composite for methanol reforming was evaluated. In the Ni-based catalysts, the dopant decreased the CO production by promoting a methanation reaction, while in the Co-based catalysts, the dopant did it by inducing a water-gas shift reaction. Co/MgO with Sc2O3 doping showed the most preferable reforming performance, high H2 production, and CO2 selectivity. ...
Monodispersed forms of metal nanoparticles are significant to overcome frightening threat of cancer. This review examined pragmatically thermal decomposition as one of the best ways to synthesize monodispersed metal nanoparticles which are stable and of small particle sizes. Controlled morphology for delivery of anticancer agent to specific cells can also be obtained with thermal decomposition. In addition to thermal decomposition, the study also looked into processes of characterization techniques, biological evaluation, toxicity of nanoparticles, and future perspectives.
Descrizione libro Royal Society Of Chemistry, United Kingdom, 2014. Hardback. Condizione libro: New. Language: English . Brand New Book. Catalysis is a central topic in chemical transformation and energy conversion. Thanks to the spectacular achievements of colloidal chemistry and the synthesis of nanomaterials over the last two decades, there have also been significant advances in nanoparticle catalysis. Catalysis on different metal nanostructures with well-defined structures and composition has been extensively studied. Metal nanocrystals synthesized with colloidal chemistry exhibit different catalytic performances in contrast to metal nanoparticles prepared with impregnation or deposition precipitation. Additionally, theoretical approaches in predicting catalysis performance and understanding catalytic mechanism on these metal nanocatalysts have made significant progress. Metal Nanoparticles for Catalysis is a comprehensive text on catalysis on Nanoparticles, looking at both their synthesis ...
The research in this dissertation examines the chemistry and applications of dendrimers in homogeneous catalysis. We examined interactions between dendrimers and charged probe molecules, prepared dendrimer-encapsulated metal nanoparticles in organic solvents, studied size-selectivity of dendrimer-encapsulted catalysts, and designed molecular rulers as in-situ probes to measure the location of dendrimer-encapsulted metal nanoparticles. The intrinsic proton binding constant and a constant that characterizes the strength of electrostatic interactions among occupied binding sites in poly(amidoamine) (PAMAM) dendrimers have been obtained by studying the effect of solution pH on the protonation of the dendrimers. The significant finding is that these two factors are greatly modulated by the unique and hydrophobic microenvironment in the dendrimer interior. Hydrophilic poly(propylene imine) (PPI) dendrimers were modified with various hydrophobic alkyl chains through an amide linkage and were then used ...
The use of biological sources such as microbes and plants can help in synthesizing nanoparticles in a reliable and eco-friendly way. The synthesis of nanoparticles by these natural sources is characterized by processes that take place near to ambient temperature and pressures and also near neutral pH. This edited volume authored by subject specialists, provides all the latest research and builds a database of bioreduction agents to various metal nanoparticles using different precursor systems. The book also highlights the different strategies such as simplicity, cost-effectiveness, environment-friendly and easily scalable, and includes parameters for controlling the size and shape of the materials developed from the various greener methods. In order to exploit the utmost potential metal nanoparticles synthesis from the different sources such as agricultural waste, flora and fauna, food waste, microbes and biopolymer systems, it is also crucial to recognize the biochemical and molecular mechanisms of
Research theme: Catalyst Diagnostics to Develop More Active Catalysts. Raman spectroscopy is a powerful method for solid catalyst characterization under operando conditions. However, its sensitivity often hampers the detection of surface adsorbates and reaction intermediates. Shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) has turned out to be a valuable addition to the catalyst characterization toolbox. SHINERS requires Au or Ag nanoparticles covered by a thin dielectric oxide coating, such as SiO2 or Al2O3, to minimize plasmonic side-reactions.. In this project, we will use spark ablation technology to deposit metal nanoparticles of various sizes and chemical compositions on shell-isolated Au and Ag nanoparticles (SHINs). These metal/SHINs will allow to investigate the adsorption of probe molecules, such as NO and CO, as well as performing structure-sensitive (e.g. CO2 and acetylene hydrogenation) and structure-insensitive (e.g. ethene hydrogenation) reactions under operando ...
The local surface plasmon resonance (LSPR) of noble metal nanoparticles has recently been exploited in numerous applications. The LSPR peak position and linewidth have been studied quite extensively, but the magnitude of the resonance has not received much attention. Analytical solutions to Maxwells Equations cannot predict the scattering cross section of arbitrarily-shaped particles at arbitrary illumination and detection angles. Dark field microscpectroscopy is a powerful tool for studying plasmon resonances of noble metal nanoparticles and for developing their applications in sensing and imaging. We present a technique for calibrating dark field microspectrometer measurements to yield quantitative spectral scattering cross sections for arbitrarily shaped particles. Values for gold nanorods and gold bipyramids are reported. The measurements suggest that, for small elongated particles, the signal can be predicted by approximations based on the total cross section ...
Page contains details about example of metal nanoparticles on titanate carrier . It has composition images, properties, Characterization methods, synthesis, applications and reference articles : nano.nature.com
A combined theoretical and experimental approach has allowed researchers to predict and verify the full structure of a monolayer-coated molecular metal nanoparticle. The methodology was tested on silver-thiolate nanoparticles, expanding on earlier knowledge about gold nanoparticles, and is expected to be applicable to a broad range of sizes of nanoparticles made of different elements.. In a paper published Friday, November 25, 2016, in the journal Science Advances, researchers from the Georgia Institute of Technology and the University of Toledo report on an X-ray-determined structure that authenticates the a priori prediction, and in conjunction with first-principles theoretical analysis, supports the underlying forecasting methodology.. Metal nanoparticles capped by organic ligands have fundamental and applied significance for understanding the physical and chemical principles controlling the assembly and atomic organization in nanocrystalline materials, and to their potential usage in fields ...
An international team of researchers led by RMIT has investigated alternatives to gold nanoparticles, which have been shown to concentrate radiation used to treat cancer but are highly expensive and mildly toxic.. Doctoral researcher Mamdooh Alqathami said the team had identified bismuth as an ideal option, with tests showing that enhancing radiotherapy by using nanoparticles containing the heavy metal almost doubled the dose of radiation to surrounding cancerous tissue.. By enhancing radiation in the tumour, doctors may be able to decrease the initial dose of radiotherapy, which will hopefully result in fewer side effects for the patient while having the same impact on the cancer, Mr Alqathami, a researcher in the School of Medical Sciences, said.. Metal nanoparticles have shown promise in improving the efficacy of radiotherapy but there is a need to find cheaper and safer alternatives for therapeutic use.. Bismuth-based nanoparticles are an attractive option as they cost only a few dollars ...
TY - JOUR. T1 - Anisotropic metal nanoparticles. T2 - Synthesis, assembly, and optical applications. AU - Murphy, Catherine J.. AU - Sau, Tapan K.. AU - Gole, Anand M.. AU - Orendorff, Christopher J.. AU - Gao, Jinxin. AU - Gou, Linfeng. AU - Hunyadi, Simona E.. AU - Li, Tan. PY - 2005/7/28. Y1 - 2005/7/28. N2 - This feature article highlights work from the authors laboratories on the synthesis, assembly, reactivity, and optical applications of metallic nanoparticles of nonspherical shape, especially nanorods. The synthesis is a seed-mediated growth procedure, in which metal salts are reduced initially with a strong reducing agent, in water, to produce ∼4 nm seed particles. Subsequent reduction of more metal salt with a weak reducing agent, in the presence of structure-directing additives, leads to the controlled formation of nanorods of specified aspect ratio and can also yield other shapes of nanoparticles (stars, tetrapods, blocks, cubes, etc.). Variations in reaction conditions and ...
Conventional Förster resonance energy transfer (FRET) processes involving a pair of fluorophore and organic quencher are restricted to an upper distance limit of ~10 nm. The application of a metal nanoparticle as a quencher can overcome the distance barrier of the traditional FRET technique. However, no standard distance dependence of this resonance energy transfer (RET) process has been firmly established. We have investigated the nonradiative energy transfer process between an organic donor (fluorescein) and gold nanoparticle quencher connected by double stranded (ds) DNA. The quenching efficiency of the gold nanoparticle as a function of distance between the donor and acceptor was determined by time-resolved lifetime analyses of the donor. Our results showed a 1/d 4 distance dependence for the RET process for longer distances (,10 nm) and 1/d 6 distance dependence for shorter distances (,10 nm). Our results clearly indicate the applicability of metal nanoparticle based quenchers for studying ...
Optical Properties of Metal Nanoparticles. Sriharsha Karumuri. Introduction. Why nanoparticles are different from bulk materials? Nanoparticles are different from bulk materials and isolated molecules because of their unique optical, electronic and chemical properties. Slideshow 6716843 by joyceta-bravo
A one step process is described for forming metal nanoparticles in polymers at atmospheric pressure and room temperature or with mild heating and stirring. The inventive process includes addition of nanoparticle precursor salts, e.g. HAuCl 4 or AgNO 3 into a
Metal nanoparticles (also known as colloidal metal) have been around for a very long time, with the original scientific references dating over one hundred and fifty years ago*. Both pure metal and metal oxide colloids are used in a wide variety of applications including catalysts, ferrofluids, biological markers, and many others. Particle size and zeta potential of these suspensions are critical physical parameters that affect functionality and stability. The SZ-100 Nanoparticle Analyzer is an excellent analytical tool for determining particle size and zeta potential of metal colloids. ...
Monolayer Protected Metal Nanoparticles have recently found widespread use in and are the focus of intensive study in many areas of scientific research ranging from biology to physics to medicine. Consisting of a nanoscale, crystalline, metallic core surrounded by a self-assembled monolayer of ligands (a 3-D SAM or ligand shell), their appeal and utility stem from their numerous unique properties-many of which arise and are modulated by the intimate spatial and electronic contact between core and shell. The ligand shell controls the particles interactions with its environment (e.g. sensing, assembly, and electron transfer ability). Furthermore, the ability to manipulate and assemble such nanomaterials through the ligand shell is paramount to their incorporation into and the development of new nanoparticle based materials and devices. However, little is known of the exact composition and packing arrangements of molecules within the ligand shell, and even less so on how to control the resulting ...
Due to high surface area, supported metal nanoparticles are thermodynamically prone to sintering. The experimental studies of this process exhibit sometimes transient bimodal particle size distributions. Such observations may result from the support heterogeneity. Looking retrospectively, one can also find the prediction that in the case of Ostwald ripening this feature can be related to charge of metal nano particles. In real systems, this charge is often associated with the metal support interaction and can be interpreted in the framework of the Schottky model. Using this model, the author shows that the charge redistribution cannot be behind bimodal particle size distributions. Moreover, the corresponding contribution to the driving force for Ostwald ripening is typically much smaller than the conventional one.
Most metal nanoparticles (NPs), except noble metal NPs, rapidly form a thin surface oxide in ambient conditions. The protective properties of these oxides improve or worsen depending on the environment, e.g., the human lung. Several properties, including the chemical/electrochemical stability and defect density, determine the capacity of these surface oxides to hinder the bulk metal from further oxidation (corrosion). The aim of this study was to investigate whether electrochemical surface oxide characterization of non-functionalized base metal NPs of different characteristics (Al, Mn and Cu) can assist in understanding their bioaccessibility (metal release) in cell media (DMEM+) and their cytotoxic properties following exposure in lung epithelial (A549) cells. The composition and valence states of surface oxides of metal NPs and their electrochemical activity were investigated using an electrochemical technique based on a graphite paste electrode to perform cyclic voltammetry in buffer ...
polarized guided waves that propagate confined to the surface of a two-dimensional array of silver (Ag) nanoparticles of average particle diameter and film thickness of approximately 400 and 154 nm, respectively, and comparable interparticle spacing. We interpret resonant features in the attenuated total reflection angular spectrum as arising from the excitation of guided waves in our discontinuous samples. The excitation of these waves is a direct consequence of the interaction of the light field with the localized resonance of the conduction electrons in the individual metal nanoparticles.. © 2000 Optical Society of America. Full Article , PDF Article ...
TY - JOUR. T1 - Apoptotic damage during co-culture of lung epithelial cells and macrophages in the presence of metal nanoparticles is modulated by TNF-α from macrophages. AU - Kim, Ki Heon. AU - Kim, Seung Yeul. AU - Chun, Bok Hwan. AU - Lee, Yong Kwon. AU - Chung, Namhyun. PY - 2011. Y1 - 2011. UR - http://www.scopus.com/inward/record.url?scp=79952721524&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=79952721524&partnerID=8YFLogxK. U2 - 10.3839/jksabc.2011.004. DO - 10.3839/jksabc.2011.004. M3 - Article. AN - SCOPUS:79952721524. VL - 54. SP - 30. EP - 36. JO - Journal of Applied Biological Chemistry. JF - Journal of Applied Biological Chemistry. SN - 1976-0442. IS - 1. ER - ...
Aluminum-ion batteries (AIBs) are attracting increasing attention as a potential energy storage system owing to the abundance of Al sources and high charge density of Al3+. However, suitable cathode materials to further advance high-performing AIBs are unavailable. Therefore, we demonstrated the compatibility of elemental metal nanoparticles (NPs) as cathode materials for AIBs. Three types of metal NPs ([email protected], [email protected], [email protected]) were formed by in-situ growing Prussian blue analogs (PBAs, Co[Co(CN)6], Fe[Fe(CN)6] and Co[Fe(CN)6]) on a natural loofa (L) by a room-temperature wet chemical method in aqueous bath, followed by a carbonization process. The employed L effectively formed graphite C-encapsulated metal NPs after heat treatment. The discharge capacity of [email protected] was superior (372 mAh g− 1) than others (103 mAh g− 1 for [email protected] and 75 mAh g− 1 for [email protected]). The novel design results in [email protected] with an outstanding long-term charge/discharge cycling performance (over 1,000 cycles) with a ...
A facile and efficient γ-radiation strategy has been developed to incorporate surface-clean metal nanoparticles (NPs) into UiO-66-NH2 in the absence of stabilizing agents and additional reductants. This approach is enabled by metal ion reduction with active e−aq and H˙ species derived from water radiolysis. Inorganic Chemistry Frontiers HOT articles for 2017
Page contains details about example of stabilized metal nanoparticles . It has composition images, properties, Characterization methods, synthesis, applications and reference articles : nano.nature.com
Stabilised Bimetallic Metal Nanoparticles in Tailor-made Carbon Nanoreactors as Catalysts for Continuous-Flow Biomass Valorisation with Supercritical Fluids Dr. R. A. Bourne,a Dr. T. W. Chamberlain,a,b Dr. U. Hintermair,c & Dr. C. D. Smithd aSchool of Process, Environmental and Mechanical Engineering, University of Leeds, bSchool of Chemistry, University of Nottingham, cCentre for Sustainable Chemical Technologies, University of Bath, dSchool…
Western Blot and Immunoblotting Products. Read about how to use gold nanoparticles and other noble metal nanoparticles in immunoblotting in the following tech note: Immunoblotting Using Noble Metal Nanoparticles Probes
Western Blot and Immunoblotting Products. Read about how to use gold nanoparticles and other noble metal nanoparticles in immunoblotting in the following tech note: Immunoblotting Using Noble Metal Nanoparticles Probes
Introduction Functionalized gold nanoparticles (AuNPs) have prospective as antimicrobial products to counter, for example, fungi and bacteria [1]. Increasing efforts have actually been committed to research study in this field, especially in the advancement of metal nanoparticles (such as copper, silver and gold nanoparticles) as anti-bacterial agents [1-4] The most common target for antibacterial agents has been gram-negative germs, owing to the multi-drug resistance phenomena observed in gram-negative bacteria [2-5]. Advancements in this area have actually been influenced by the need to discover the type of metal nanoparticles, and the functionalization of such nanoparticles, that will display the best…. Further Info ...
Introduction Functionalized gold nanoparticles (AuNPs) have prospective as antimicrobial products to counter, for example, fungi and bacteria [1]. Increasing efforts have actually been committed to research study in this field, especially in the advancement of metal nanoparticles (such as copper, silver and gold nanoparticles) as anti-bacterial agents [1-4] The most common target for antibacterial agents has been gram-negative germs, owing to the multi-drug resistance phenomena observed in gram-negative bacteria [2-5]. Advancements in this area have actually been influenced by the need to discover the type of metal nanoparticles, and the functionalization of such nanoparticles, that will display the best…. Further Info ...
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Noble metal nanoparticles interact strongly with visible light due to resonant excitation of conduction electron oscillations, an interaction referred to as a local surface plasmon resonance (LSPR) interaction. This LSPR interaction results in an enhancement of the electromagnetic field surrounding the nanoparticle, with a concomitant enhancement of optical signals. Recent interest in SER spectroscopy (SERS) has been rekindled by the observation of single molecule SERS. Nanofabrication provides a method for producing metal substrates for SERS with well-defined size and shape characteristics. Gold nanopillar structures are fabricated for this work by electron beam lithography. Rabbit skeletal-myosin-II HMM and actin can be produced in gram quantities and provide the basis for a highly reproducible in-vitro motility assay system. Using this well established assay linked with SERS we can look at how the heads of myosin interact with filaments of actin to produce steps in greater detail. This ...
Spanish researchers have shown that carbon nanotubes (CNTs) constitute the ideal templates for the formation of one-dimensional strings of metal nanoparticles, with potential uses as waveguides. Professor Luis Liz-Marz n, who heads the Nanoparticles and Nanostructures Group at the University of Vigo in Spain, explained to Nanowerk: Linear arrays would have extremely interesting applications, for instance, in the construction of nanoelectronic circuits, but could also be used in photonics, since wave guiding via surface plasmons has been predicted for metal nanoparticle chains. Source: ...
Nanomaterials are being increasingly used for the development of electrochemical DNA biosensors, due to the unique electrocatalytic properties found in nanoscale materials. They offer excellent prospects for interfacing biological recognition events with electronic signal transduction and for designing a new generation of bioelectronic devices exhibiting novel functions. In particular, nanomaterials such as noble metal nanoparticles (Au, Pt), carbon nanotubes (CNTs), magnetic nanoparticles, quantum dots and metal oxide nanoparticles have been actively investigated for their applications in DNA biosensors, which have become a new interdisciplinary frontier between biological detection and material science. In this article, we address some of the main advances in this field over the past few years, discussing the issues and challenges with the aim of stimulating a broader interest in developing nanomaterial-based biosensors and improving their applications in disease diagnosis and food safety examination.
Oxide scales are supposed to protect alloys from extensive corrosion, but scientists at U.S. Department of Energys Argonne National Laboratory have discovered metal nanoparticle chinks in this armor.
The ability to study oxidation, reduction, and other chemical transformations of nanoparticles in real time and under realistic conditions is a nontrivial task due to their small dimensions and the often challenging environment in terms of temperature and pressure. For scrutinizing oxidation of metal nanoparticles, visible light optical spectroscopy based on the plasmonic properties of the metal has been established as a suitable method. However, directly relying on the plasmonic resonance of metal nanoparticles as a built-in probe to track oxidation has a number of drawbacks, including the loss of optical contrast in the late oxidation stages. To address these intrinsic limitations, we present a plasmonic heterodimer-based nanospectroscopy approach, which enables continuous self-referencing by using polarized light to eliminate parasitic signals and provides large optical contrast all the way to complete oxidation. Using Au-Cu heterodimers and combining experiments with finite-difference time-domain
The speed of nanoparticle assembly can be accelerated with the assistance of the molecule that carries life s genetic instructions, DNA, a team of researchers at the U.S. Department of Energy s Brookhaven National Laboratory recently found. Nanoparticles, particles with dimensions on the order of billionths of a meter, could potentially be used for more efficient energy generation and data storage, as well as improved methods for diagnosing and treating disease. Source: ...
The effects of silver nanoparticle on the physical properties of syndiotactic polypropylene (sPP) were investigated in terms of rheological responses and crystallization behavior under shear. Silver nanoparticle played as the nucleating agent of sPP by increasing crystallization temperature (Tc) and heat of crystallization (ΔHc). The introduction of silver nanoparticles more than 1 wt% brought about the rise of dynamic viscosity when compared to pure sPP. sPP with 5 wt% silver nanoparticle exhibited the higher tan δ and lower relaxation time than the others in the low frequency range. However, the effects of silver nanoparticle on the rheological properties became less noticeable when the loading level was higher than 5 wt%.
TY - JOUR. T1 - Effects of silver nanoparticles on the interactions of neuron- and glia-like cells. T2 - Toxicity, uptake mechanisms, and lysosomal tracking. AU - Hsiao, I. Lun. AU - Hsieh, Yi Kong. AU - Chuang, Chun Yu. AU - Wang, Chu Fang. AU - Huang, Yuh Jeen. PY - 2017/6/1. Y1 - 2017/6/1. N2 - Silver nanoparticles (AgNPs) are commonly used nanomaterials in consumer products. Previous studies focused on its effects on neurons; however, little is known about their effects and uptake mechanisms on glial cells under normal or activated states. Here, ALT astrocyte-like, BV-2 microglia and differentiated N2a neuroblastoma cells were directly or indirectly exposed to 10 nm AgNPs using mono- and co-culture system. A lipopolysaccharide (LPS) was pretreated to activate glial cells before AgNP treatment for mimicking NP exposure under brain inflammation. From mono-culture, ALT took up the most AgNPs and had the lowest cell viability within three cells. Moreover, AgNPs induced H2O2 and NO from ...
Silver nanoparticles have been shown to inhibit viruses. However, very little is known about the mechanism of antiviral activity. This study tested the hypothesis that 25-nm silver nanoparticles inhibited Vaccinia virus replication by preventing viral entry. Plaque reduction, confocal microscopy, and beta-galactosidase reporter gene assays were used to examine viral attachment and entry in the presence and absence of silver nanoparticles. To explore the mechanism of inhibition, viral entry experiments were conducted with silver nanoparticles and small interfering RNAs designed to silence the gene coding for p21-activated kinase 1, a key mediator of macropinocytosis. The silver nanoparticles caused a 4- to 5-log reduction in viral titer at concentrations that were not toxic to cells. Virus was capable of adsorbing to cells but could not enter cells in the presence of silver nanoparticles. Virus particles that had adsorbed to cells in the presence of silver nanoparticles were found to be infectious upon
The biological approach to synthesize metal nanoparticles is an important aspect of current nanotechnology research. Silver nanoparticles have been well-known for their inhibitory and antimicrobial effects. The ever-increasing antibiotic resistance in pathogenic and opportunistic microorganisms is a major threat to the health care industry. In the present investigation, silver nanoparticles have been successfully biosynthesized by Streptomyces sp JAR1. Biosynthesized silver nanoparticles were characterized by means of several analytical techniques including a UV-Visible spectrophotometer, Fourier transform infrared spectroscopy, X-ray diffraction pattern analysis, and atomic force microscopy. An evaluation of the antimicrobial activity of silver nanoparticles (AgNPs) was carried out against clinically important pathogenic microorganisms. The metal nanoparticles were also evaluated for their combined effects with antibiotics against the clinical pathogens. The anti-bacterial activities of the antibiotics
The use of less hazardous chemicals or natural material in place of toxic chemical for the formation of metal nanoparticle is known as green synthesis. The present paper deals with greener approach for the synthesis of silver (Ag) nanoparticles. The Saraca asoca plant leaves extract solution was used for the silver nanoparticles. Confirmation of Ag nanoparticles has been done using various characterization techniques viz. structural by X-Ray Diffraction (XRD), morphological analysis by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and elemental analysis by Energy Dispersive X-ray Spectroscopy (EDX). The particle size of silver nanoparticle is found to be 24.85 nm. The particle exhibits good antibacterial properties against Staphylococci aures, Streptococci pyogens, Salmonella typhi.
TY - GEN. T1 - Functionalized bio-nanoparticles in immunosensing using surface-enhanced raman scattering methods. AU - Lin, Chi Chang. AU - Yu, Chen Yuan. AU - Yang, Ying Mei. AU - Chen, Yan Fu. AU - Chang, Hsien Chang. PY - 2009/10/12. Y1 - 2009/10/12. N2 - An unique, sensitive, and highly specific immunoassay system using gold nanoparticles and Surface-Enhanced Raman Spectroscopy (SERS) is described. To demonstrate the analytical capabilities of the new technique, Raman reporter (DTNB) that is coimmobilized with biospecific anti-protein A on gold nanoparticles (AuNP). Anti-protein A-AuNP-DTNB, which combing both electromagnetic field and chemical enhancement, was used to exploits the SERS-derived signal. A dynamic range of 2-3 orders of magnitude and 1-10 pg/mL of detection limitation of protein A were achieved. The results indicated this new technique could be used in clinical diagnostic applications with fast, high sensitivity and highthroughput screening of antibodies.. AB - An unique, ...
Gold nanoparticles reflect different colors when exposed to light. Gold nanoparticles properties can be changed by altering their structure, shape and size. These advantages have been driving the global gold nanoparticles market in major end-use industries including electronics, sensory probes, therapeutic agents and medical applications. Gold nanoparticles are available at nano scale size ranging from 5nm to 100nm. Gold nanoparticles market has been witnessing strong growth over the last few years on account of increasing demand from medical and dentistry sector and trend is expected to continue over the forecast period. Growing application scope of nanotechnology in medical sector especially in diagnostics and imaging application is the key factor expected to drive the market over the next six years. Gold nanoparticles are used in detection of tumor cells and cancer drug delivery. These advantageous factors are expected to boost nanoparticles demand over the forecast period. Gold nanoparticles ...
Many studies addressing the toxicity of silver nanomaterials have found that smaller sized silver nanoparticles are usually more toxic to organisms and in cell culture than particles of larger sizes yet it is not entirely clear why. We investigated the size dependent toxicity of silver nanoparticles by measuring the response of embryonic zebrafish (Danio rerio) following exposure to a library of thirteen distinct silver nanoparticle size distributions with mean diameters between 8.9 nm and 112.6 nm. Data analysis using dose‐response modeling revealed that silver nanoparticles (AgNP) induced embryo toxicity that is dependent on the total surface area and not on the mass or particle number in solution. Included in this study is a comparison between embryo toxicity induced by silver nitrate (AgNO₃) and AgNPs for cardiovascular endpoints, as well as an investigation into the influence of the chorion on AgNP toxicity. This study demonstrates the importance of using alternative dose metrics in ...
Article Silver nanoparticle toxicity to Daphnia magna is a function of dissolved silver concentration. The most persistent question regarding the toxicity of silver nanoparticles (AgNPs) is whether this toxicity is due to the nanoparticles themselves...
We present a microscopic theory of quantum-size effects in surface-enhanced Raman scattering (SERS) from molecules adsorbed on small metal nanoparticles. In noble-metal nanoparticles, the confining potential has different effect on s-band and d-band electrons. Namely, the spillout of delocalized sp-electrons beyond the classical nanoparticle boundary results in an incomplete embedding of s-electron distribution in the background of localized d-electrons whose density profile follows more closely the classical shape. We demonstrate that a reduction of d-electron screening in the surface layer leads to the enhancement of the surface plasmon local field acting on a molecule located in a close proximity to metal surface. Our numerical calculations of Raman enhancement factor, performed using time-dependent local density approximation, show additional enhancement of the Raman signal which becomes more pronounced for small nanoparticles due to the larger ratio of surface layer to overall nanoparticle size.
TY - JOUR. T1 - Multiplexed DNA detection with DNA-functionalized silver and silver/gold nanoparticle superstructure probes. AU - Kim, Ji Young. AU - Lee, Jae-Seung. PY - 2012/1/20. Y1 - 2012/1/20. N2 - DNA-functionalized silver and silver/gold bimetallic nanoparticle superstructure probes with controllable sizes and optical properties are synthesized using monothiol DNA and dithiothreitol. The superstructures exhibit a very narrow size distribution, which can be easily controlled by balancing the ratio of dithiothreitol and DNA. These superstructures assemble reversibly in a highly cooperative manner, and are SERS active. Multiplexed colorimetric detection of DNA targets using these superstructure probes has been demonstrated to identify three different DNA target sequences that are associated with three lethal diseases, respectively.. AB - DNA-functionalized silver and silver/gold bimetallic nanoparticle superstructure probes with controllable sizes and optical properties are synthesized using ...
The use of bacterial strains in the synthesis of silver nanoparticles emerges as an eco-friendly and exciting approach towards the field of research in life sciences. In this present work, microbial production of silver nanoparticles was investigated using the bacterial strain Bacillus cereus GAD 20. The test bacterium was isolated from soil samples from Gadchiroli district of Maharashtra state grown on Hichrome Bacillus Agar and Bacillus Differentiation Agar and further identified on the basis of 16S rRNA. Synthesized silver nanoparticles were characterized by UV-Vis spectroscopy and the maximum absorbance was found to be around λ-427nm. The particle size of silver nanoparticles was studied by Scanning Electron Microscopy (SEM). FTIR analysis confirms the presence of proteins as stabilizing agents. The antibacterial activity of silver nanoparticles was studied against multi drug resistant bacterial strains of Escherichia.coli and Staphylococcus.aureus. Zone of inhibition of microbes in ...
Using Plasmonic Metal Nanoparticles to Enhance Solar Cell Efficiency - Bangladesh Making Significant Progress in Renewable Energy Technology
1. Introduction. Carbon nanotubes (CNTs) have been proposed as the ideal metal catalyst support for electrocatalytic and sensing applications because of their unique electrical properties, high chemical stability and high surface-to-volume ratios.1 Decoration of the walls of carbon nanotubes (CNTs)2 with functional groups3 and/or nanoparticles has been performed to add additional functionality to CNTs. In recent years, decoration of CNTs has been used to improve performance of their various applications4 such as making nanotubes magnetic,5 to grow secondary structures inside the nanotubes to increase the available surface for catalysis6 or in electronics.7 Modern electronics devices based on carbon nanotubes (CNTs) have shown that their performance is influenced by a potential barrier existing at the metal-CNT contact that governs the electron injection into the carbon nanotubes.7. To functionalize the CNTs with metal nanoparticles, an ionic adsorption followed by a direct heating can be ...
Synthesized thiolate boronic acid was found to complex with both a polysaccharide (dextran) and a monosaccharide (glucose) with similar affinities but displayed more affinity with dextran than with glucose when capped as a ligand on silver nanoparticle. Coupling on multiple sites of dextran, the silver particles were aggregated. The aggregated particles displayed a decrease of absorbance at 397 nm and an increase at 640 nm. Luminescence intensity displayed an upward deviation increase with the concentration of dextran. The luminescence spectral change was ascribed to surface-enhanced fluorescence by the enhanced field from the aggregated metallic particles.
A gold-nanoparticles (Au NPs)-Rhodamine 6G (Rh6G) based fluorescent sensor for detecting Hg(II) in aqueous solution has been developed. Water-soluble and monodisperse gold nanoparticles (Au NPs) has been prepared facilely and further modified with thioglycolic acid (TGA). Free Rh6G dye was strongly fluorescent in bulk solution. The sensor system composing of Rh6G and Au NPs fluoresce weakly as result of fluorescence resonance energy transfer (FRET) and collision. The fluorescence of Rh6G and Au NPs based sensor was gradually recovered due to Rh6G units departed from the surface of functionalized Au NPs in the presence of Hg(II). Based on the modulation of fluorescence quenching efficiency of Rh6G-Au NPs by Hg(II) at pH 9.0 of teraborate buffer solution, a simple, rapid, reliable and specific turn-on fluorescent assay for Hg(II) was proposed. Under the optimum conditions, the fluorescence intensity of sensor is proportional to the concentration of Hg(II). The calibration graphs are linear over the range
TY - JOUR. T1 - Measurement of adsorption constants of laccase on gold nanoparticles to evaluate the enhancement in enzyme activity of adsorbed laccase. AU - Almeida, Miguel Peixoto de AU - Quaresma, Pedro. AU - Sousa, Susana. AU - Couto, Cláudia. AU - Gomes, Inês. AU - Krippahl, Ludwig. AU - Franco, Ricardo. AU - Pereira, Eulália. N1 - Marta Giza is acknowledged for expert utilization of the UCSF Chimera package. Chimera is developed by the Resource for Biocomputing, Visualization, and Informatics at the University of California, San Francisco (supported by NIGMS P41-GM103311). This work was supported by (a) Unidade de Ciencias Biomoleculares Aplicadas-UCIBIO which is financed by Portuguese national funds from FCT/MEC (UID/Multi/04378/2013) and co-financed by the ERDF under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007728); and NOVA LINCS UID/CEC/04516/2013; and (b) European Union (FEDER funds through COMPETE) and National Funds (FCT, Fundacao para a Ciencia e Tecnologia), under ...
The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved. AIM To develop a screening test for celiac disease based on the coating of gold nanoparticles with a peptide sequence derived from gliadin, the protein that triggers celiac disease. METHODS 20 nm gold nanoparticles were first coated with NeutrAvidin. A long chain Polyethylene glycol (PEG) linker containing Maleimide at the Ω-end and Biotin group at the α-end was used to ensure peptide coating to the gold nanoparticles. The maleimide group with the thiol (-SH) side chain reacted with the cysteine amino acid in the peptide sequence and the biotinylated and PEGylated peptide was added to the NeutrAvidin coated gold nanoparticles. The peptide coated gold nanoparticles were then converted into a serological assay. We used the peptide functionalised gold nanoparticle-based assay on thirty patient serum samples in a blinded assessment and compared our results with the previously run serological and pathological ...
The increased bioavailability of nanoparticles engineered for good dispersion in water may have biological and environmental impacts. To examine this issue, the authors assessed the biological effects in nematodes as they relate to exposure to silver nanoparticles (AgNPs) of different sizes at low (1 mg/L Ag), medium (10 mg/L Ag), and high concentrations (100 mg/L Ag). Over multiple generations, the authors found that the smallest particle, at 2 nm, had a notable impact on nematode fertility. In contrast, the largest particle, at 10 nm, significantly reduced the lifespan of parent nematodes (P0) by 28.8% and over the span of 3 generations (F1-F3). In addition, a computer vision system automatically measured the adverse effects in body length and motility, which were not size-dependent ...
Recently, gold nanoparticles (AuNPs) are used for drug delivery in treating several neurological disorders e.g., Alzheimers disease (AD), Parkinsons disease, Stroke and trauma. In addition, use of AuNPs for diagnostic purposes in various diseases are also common in clinical medicine. However, the neurotoxic effects of AuNPs in vivo studies are not well explored. Thus, it would be interesting to examine AuNPs neurotoxicity in vivo models in relation to size related effects on brain pathology. We examined the effects of moderate doses of AuNPs of 3 different sizes (5 nm, 10 nm and 40 nm) administered either though intraperitoneally (10 mg/kg, i.p.), intravenously (5 mg/kg, i.v.), intracarotidly (2 mg/kg, i.c.a.) or intracerebroventricularly (20 µg in 20 µl, i.c.v.) in rats (Age 20 to 25 weeks). Blood-brain barrier (BBB) breakdown to Evans blue albumin (EBA 3 ml/kg, i.v.) and [131]-Iodine (100 µCi/kg, i.v.) was examined 24 h after AuNPs administration in the brain in relation to edema formation and
According to a new market report by Lucintel, the future of the |a href=https://www.lucintel.com/cerium-oxide-nanoparticle-market.aspx>cerium oxide nanoparticle|/a> market looks promising with opportunities in catalyst, biomedical, and energy applications. The cerium oxide nanoparticle market is expected to grow with a CAGR of 19% from 2019 to 2024. The major drivers for this market are increasing use of cerium oxide nanoparticles in various applications, rising focus of governments on nanotec
TY - JOUR. T1 - Protein-assisted 2D assembly of gold nanoparticles on a polysaccharide surface. AU - Taajamaa, Laura. AU - Rojas, Orlando J.. AU - Laine, Janne. AU - Yliniemi, Kirsi. AU - Kontturi, Eero. PY - 2013/1/2. Y1 - 2013/1/2. KW - Nanoparticles; Specific Adsorption; Cationic and anionic surfaces. KW - Nanoparticles; Specific Adsorption; Cationic and anionic surfaces. KW - Nanoparticles. KW - Specific Adsorption. KW - Cationic and anionic surfaces. UR - http://pubs.rsc.org/en/Content/ArticleLanding/2013/CC/c2cc37288f. U2 - 10.1039/c2cc37288f. DO - 10.1039/c2cc37288f. M3 - Article. VL - 49. SP - 1318. EP - 1320. JO - Chemical Communications. JF - Chemical Communications. SN - 1359-7345. IS - 13. ER - ...
Figure 1: Silver Nanoparticle Synthesis Using Monosaccharides and Their Growth Inhibitory Activity against Gram-Negative and Positive Bacteria
Using optical forces it is possible to print colloidal metallic nanoparticles on specific locations of a substrate, directly from the suspension. See for example the map of Argentina made of individual gold nanoparticles of 60 nm in diameter.. Making a careful use of optical forces, tuning focused laser beams on and off the plasmonic resonance of the metallic nanoparticles, it is possible to connect nanoparticles. Julián gargiulo, Ianina Violi, Santiago Cerrotta and Emiliano Cortés, under the direction of Prof. Fernando Stefani, managed to connect single gold nanoparticles to single silver nanoparticles, both of 60 nm in diameter.. This work constitutes an essential step toward the application of the vast variety of colloidal nanoparticles in circuits and devices.. J. Gargiulo, S. Cerrota, E. Cortés, I. L. Violi, F. D. ...
The objective of the present investigation was to evaluate the effects of taurine and Au nanoparticles on the expression of genes related to embryonic muscle development and on the morphological characteristics of muscles. Fertilised chicken eggs (n = 160) were randomly divided into four groups: without injection (Control) and with injection of Au nanoparticles (NanoAu), taurine (Tau) or Au nanoparticles with taurine (NanoAu + Tau). The experimental solutions were given in ovo, on the third day of incubation, by injecting 0.3 ml of the experimental solution into the air sack. The embryos were evaluated on the 20th day of incubation. The methods included gene expression at the mRNA and protein levels, immunohistochemistry, histology and microscopy. In groups NanoAu, Tau and NanoAu + Tau, the muscle structure and the number of muscle cells were affected. Furthermore, taurine increased fibre diameter, the total number of nuclei, the proportion of proliferating cell nuclear antigen (PCNA)-positive ...