Phototransformation of Alkanethiol-derivatized Noble Metal Nanoparticle

2000 ◽  
Vol 72 (1-2) ◽  
pp. 91-99 ◽  
Author(s):  
Chil Seong Ah ◽  
Hyouk Soo Han ◽  
Kwan Kim ◽  
Du-Jeon Jang
Keyword(s):  
Noble Metal ◽  
Thermal Conduction ◽  
Heat Dissipation ◽  
Dissociation Rate ◽  
Oxidation Potential ◽  
Metal Nanoparticle ◽  
Noble Metal Nanoparticles ◽  
Shape Transformation ◽  
Atomization Enthalpy ◽  
The Difference

Photon-initiated shape transformation of n-alkanethiol-derivatized noble metal nanoparticles has been studied with variations of metal, alkanethiol, and solvent. Silver nanoparticles undergo fragmentation upon irradiation while gold ones barely do. Silver/gold composite particles follow the case of silver with a reduced efficiency. The efficiency decreases as alkanethiol length or solvent dipole moment increases. Following the conduction of thermalized photon energy, alkanethiol can dissociate in a period of heat dissipation, and some of dethiolated particles fragment within the recombination time. Prior to the thermal conduction, shape transformation via melt and vaporization also occurs for both metals but this effect is less apparent for silver because of more notable fragmentation followed. The difference in the transformation of two metals is ascribed to the differences in work function, oxidation potential, atomization enthalpy, and particle size. Smaller fragmentation efficiency with more polar solvent or longer alkanethiol is attributed mainly to relatively smaller dissociation rate compared with heat dissipation rate.

scholarly journals Current Strategies for Noble Metal Nanoparticle Synthesis

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Giyaullah Habibullah ◽  
Jitka Viktorova ◽  
Tomas Ruml
Keyword(s):  
Noble Metal ◽  
Noble Metals ◽  
Drug Carriers ◽  
Industrial Applications ◽  
Metal Nanoparticle ◽  
Noble Metal Nanoparticles ◽  
Synthesis Methods ◽  
Gold And Silver Nanoparticles ◽  
Diverse Range ◽  
The Past

AbstractNoble metals have played an integral part in human history for centuries; however, their integration with recent advances in nanotechnology and material sciences have provided new research opportunities in both academia and industry, which has resulted in a new array of advanced applications, including medical ones. Noble metal nanoparticles (NMNPs) have been of great importance in the field of biomedicine over the past few decades due to their importance in personalized healthcare and diagnostics. In particular, platinum, gold and silver nanoparticles have achieved the most dominant spot in the list, thanks to a very diverse range of industrial applications, including biomedical ones such as antimicrobial and antiviral agents, diagnostics, drug carriers and imaging probes. In particular, their superior resistance to extreme conditions of corrosion and oxidation is highly appreciated. Notably, in the past two decades there has been a tremendous advancement in the development of new strategies of more cost-effective and robust NMNP synthesis methods that provide materials with highly tunable physicochemical, optical and thermal properties, and biochemical functionalities. As a result, new advanced hybrid NMNPs with polymer, graphene, carbon nanotubes, quantum dots and core–shell systems have been developed with even more enhanced physicochemical characteristics that has led to exceptional diagnostic and therapeutic applications. In this review, we aim to summarize current advances in the synthesis of NMNPs (Au, Ag and Pt).

Noble metal nanoparticle-decorated TiO2 nanobelts for enhanced photocatalysis

2014 ◽  
Vol 07 (05) ◽  
pp. 1450064 ◽  
Author(s):  
Haiyan He ◽  
Ping Yang ◽  
Changchao Jia ◽  
Yanping Miao ◽  
Jie Zhao ◽  
...  
Keyword(s):  
Noble Metal ◽  
Au Nanoparticles ◽  
Acid Corrosion ◽  
Metal Nanoparticle ◽  
Noble Metal Nanoparticles ◽  
Au Nanoparticle ◽  
Chloroauric Acid ◽  
Sem Images ◽  
Photogenerated Electrons ◽  
Coarse Surface

TiO 2 nanobelts have been fabricated through a hydrothermal method and subsequently sulfuric-acid-corrosion-treated for a rough surface. Noble metal nanoparticles such as Ag and Au were deposited on the coarse surface of TiO 2 nanobelts via a coprecipitation procedure. Ag – TiO 2 nanobelts were prepared in ethanolic solution contained silver nitrate ( AgNO 3) and sodium hydroxide ( NaOH ). Au – TiO 2 nanobelts were obtained in chloroauric acid ( HAuCl 4) using sodium borohydride ( NaBH 4) as the reductant. It is confirmed by the results of XRD patterns together with the SEM images that the composite of noble metal and TiO 2 nanobelts were obtained successfully and the Ag or Au nanoparticles were well-dispersed on the TiO 2 nanobelts. Moreover, the as-prepared Ag and Au nanoparticle-decorated TiO 2 nanobelts represent an enhanced photocatalytic activity compared with pure TiO 2 nanobelts, which is due to the fact that the Ag and Au nanoparticles on the surface of TiO 2 nanobelts act as sinks for the photogenerated electrons and promote the separation of the electrons and holes.

Bioinspired nanophotosensitizers: synthesis and characterization of porphyrin–noble metal nanoparticle conjugates

2016 ◽  
Vol 40 (1) ◽  
pp. 724-731 ◽  
Author(s):  
Jayeeta Bhaumik ◽  
Gitanjali Gogia ◽  
Seema Kirar ◽  
Lekshmi Vijay ◽  
Neeraj S. Thakur ◽  
...  
Keyword(s):  
Metal Nanoparticles ◽  
Noble Metal ◽  
Metal Nanoparticle ◽  
Noble Metal Nanoparticles ◽  
Synthesis And Characterization

Conjugatable and compact porphyrinic photosensitizer nanoparticle conjugates were developed through rational synthesis followed by conjugation with noble metal nanoparticles.

Eco-Fabrication of Metal Nanoparticle Related Materials by Home Electric Appliances

2009 ◽  
Vol 620-622 ◽  
pp. 185-188 ◽  
Author(s):  
Yamato Hayashi ◽  
Masahiro Inoue ◽  
Ichitito Narita ◽  
Katsuaki Suganuma ◽  
Hirotsugu Takizawa
Keyword(s):  
Metal Oxides ◽  
Metal Nanoparticles ◽  
Noble Metal ◽  
Metal Nanoparticle ◽  
Metal Particles ◽  
Noble Metal Nanoparticles ◽  
Strong Reduction ◽  
Noble Metal Oxides ◽  
Ecology And Economy ◽  
Suitable Process

Applications of various noble metal nanoparticles were investigated for newly, ecology and economy home electric appliances (microwave, ultrasonic) used system. Noble metal oxides have merit in metal particles fabrication, as one of these example example, there are decomposed by only heating in air. That is, noble metal oxide don't use strong reduction atmosphere. This reduction is ecologically clean, because many noble metal oxides are not toxic and during decomposition O2 is evolved. We have reduced noble metal oxides by microwave and ultrasound, and tried to fabricate noble metal nanoparticles, and investigated various processing. These energy are widely used by home electric appliances. By choosing suitable process and conditions, it is reasonable to expect that home electric appliances ecology and economy fabrications can be extended to obtain simply various noble metal nanoparticles related materials.

scholarly journals CHEMICAL INTERACTIONS AT NOBLE METAL NANOPARTICLE SURFACES — CATALYSIS, SENSORS AND DEVICES

COSMOS ◽  
2007 ◽  
Vol 03 (01) ◽  
pp. 103-124 ◽  
Author(s):  
A. SREEKUMARAN NAIR ◽  
RENJIS T. TOM ◽  
V. R. RAJEEV KUMAR ◽  
C. SUBRAMANIAM ◽  
T. PRADEEP
Keyword(s):  
Noble Metal ◽  
Metal Nanoparticle ◽  
Noble Metal Nanoparticles ◽  
Chemical Interactions ◽  
Surface Binding ◽  
Flow Sensors ◽  
Gold And Silver Nanoparticles ◽  
Cyt C ◽  
Tunable Optical Properties ◽  
Sensing Characteristics

In this paper, a summary of some of the recent research efforts in our laboratory on chemical interactions at noble metal nanoparticle surfaces is presented. The article is divided into five sections, detailing with (i) interactions of simple halocarbons with gold and silver nanoparticle surfaces at room temperature by a new chemistry and the exploitation of this chemistry in the extraction of pesticides from drinking water, (ii) interaction of biologically important proteins such as Cyt c, hemoglobin and myoglobin as well as a model system, hemin with gold and silver nanoparticles and nanorods forming nano–bio conjugates and their surface binding chemistry, (iii) formation of polymer–nano composites with tunable optical properties and temperature sensing characteristics by single and multi-step methodologies, (iv) nanomaterials-based flow sensors and (v) composites of noble metal nanoparticles and metallic carbon nanotubes showing visible fluorescence induced by metal–semiconductor transition.

scholarly journals The Effect of Ligands on Noble Metal Nanoparticles as Drug Delivery Systems to the Brain

2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Shailee Shroff ◽  
Chad Curtis
Keyword(s):  
Drug Delivery ◽  
Metal Nanoparticles ◽  
Noble Metal ◽  
Invasive Surgery ◽  
Drug Delivery Systems ◽  
Cell Types ◽  
Delivery Systems ◽  
Metal Nanoparticle ◽  
Noble Metal Nanoparticles ◽  
The Brain

metal nanoparticles have been used to address these diseases in the brain, however very few of these formulations have made it through clinical trials. This review will be discussing the role of noble metal nanoparticles as drug delivery systems specifically to the brain. A common problem many researchers and clinical physicians are facing problems because they are unable to access the brain without highly invasive surgery. Nanoparticles allow access to the brain without invasive surgery. Noble metal nanoparticles (NMNPs) are of particular interest because of their inherent characteristics which are amplified or reduced by ligands. The various ligands available change the method of transportation for a NMNPs traveling through the blood barrier. We will examine various ligands and their benefits and potential drawbacks. Furthermore, the optimal usage for each ligand and associated nanoparticle will also be examined. This review will go into detail about pure noble metal nanoparticle, glucose, PEG, CTAB, Transferrin, Anti-Microbial Peptide, and Chitosan as coatings. All of these are commonly used among researchers. The absorptivity into various cell types in the brain along with future implications will be examined.

scholarly journals Wafer-level integration of self-aligned high aspect ratio silicon 3D structures using the MACE method with Au, Pd, Pt, Cu, and Ir

2020 ◽  
Vol 11 ◽  
pp. 1439-1449
Author(s):  
Mathias Franz ◽  
Romy Junghans ◽  
Paul Schmitt ◽  
Adriana Szeghalmi ◽  
Stefan E Schulz
Keyword(s):  
Aspect Ratio ◽  
Noble Metal ◽  
Silicon Nanowires ◽  
High Aspect Ratio ◽  
Microelectromechanical Systems ◽  
High Volume ◽  
Metal Nanoparticle ◽  
Noble Metal Nanoparticles ◽  
Wafer Level ◽  
3D Structures

The wafer-level integration of high aspect ratio silicon nanostructures is an essential part of the fabrication of nanodevices. Metal-assisted chemical etching (MACE) is a promising low-cost and high-volume technique for the generation of vertically aligned silicon nanowires. Noble metal nanoparticles were used to locally etch the silicon substrate. This work demonstrates a bottom-up self-assembly approach for noble metal nanoparticle formation and the subsequent silicon wet etching. The macroscopic wafer patterning has been done by using a poly(methyl methacrylate) masking layer. Different metals (Au, Pt, Pd, Cu, and Ir) were investigated to derive a set of technologies as platform for specific applications. Especially, the shape of the 3D structures and the resulting reflectance have been investigated. The Si nanostructures fabricated using Au nanoparticles show a perfect light absorption with a reflectance below 0.3%. The demonstrated technology can be integrated into common fabrication processes for microelectromechanical systems.

scholarly journals Noble metal nanoparticles in biosensors: recent studies and applications

2017 ◽  
Vol 6 (3) ◽  
pp. 301-329 ◽  
Author(s):  
Hedieh Malekzad ◽  
Parham Sahandi Zangabad ◽  
Hamed Mirshekari ◽  
Mahdi Karimi ◽  
Michael R. Hamblin
Keyword(s):  
Noble Metal ◽  
Dna Sequences ◽  
Signal Amplification ◽  
Metal Nanoparticle ◽  
Noble Metal Nanoparticles ◽  
Optical Surface ◽  
Whole Cells ◽  
Good Ability ◽  
Good Biocompatibility ◽  
Higher Sensitivity

AbstractThe aim of this review is to cover advances in noble metal nanoparticle (MNP)-based biosensors and to outline the principles and main functions of MNPs in different classes of biosensors according to the transduction methods employed. The important biorecognition elements are enzymes, antibodies, aptamers, DNA sequences, and whole cells. The main readouts are electrochemical (amperometric and voltametric), optical (surface plasmon resonance, colorimetric, chemiluminescence, photoelectrochemical, etc.) and piezoelectric. MNPs have received attention for applications in biosensing due to their fascinating properties. These properties include a large surface area that enhances biorecognizers and receptor immobilization, good ability for reaction catalysis and electron transfer, and good biocompatibility. MNPs can be used alone and in combination with other classes of nanostructures. MNP-based sensors can lead to significant signal amplification, higher sensitivity, and great improvements in the detection and quantification of biomolecules and different ions. Some recent examples of biomolecular sensors using MNPs are given, and the effects of structure, shape, and other physical properties of noble MNPs and nanohybrids in biosensor performance are discussed.

scholarly journals Synthesis and Applications of Processable Prussian Blue Nanoparticles

2020 ◽  
pp. 93-107
Author(s):  
Prem C. Pandey ◽  
Priyanshi Pandey
Keyword(s):  
Heterogeneous Catalysis ◽  
Prussian Blue ◽  
Noble Metal ◽  
Present Report ◽  
Reducing Agents ◽  
Metal Nanoparticle ◽  
Noble Metal Nanoparticles ◽  
Synthetic Approach ◽  
Typical Application ◽  
Prussian Blue Nanoparticles

The present report describes a comparative study on chemical synthesis of processable Prussian blue Nanoparticles (PBNPs) suitable for developing PB-based devices. Controlled nucleation of PBNP from single precursors, Potassium hexacyanoferrate, has been recorded as a function of reducing and stabilizing ability of some active organic reducing agents. The use of organic reagent control the nucleation process yielding PBNPs displaying both homogeneous and heterogeneous catalysis. Four different systems of active organic reducing agents i.e.: (1) 3-aminopropyltrimethoxysilane (3-APTMS) and cyclohexanone, (2) tetrahydrofuran hydroperoxide, (3) tetrahydrofuran and hydrogen peroxide and (4) tetrahydrofuran hydroperoxide and 2-(3, 4-epoxycyclohexyl) ethyltrimethoxysilane resulted the formation of PBNP1, PBNP2, PBNP3 and PBNP4 displaying sensitivity of analysis to the order of 480, 330 350 and 400 mA mM-1 cm-2 respectively.The as reported process also enable the controlled synthesis of noble metal nanoparticles introducing new rout for yielding Prussian blue-noble metal nanoparticle nanocomposite that manipulate the catalytic/elecrocatalytic activity for targeted system. As made PBNPs undergo the formation of homogeneous nanodispersion with gold nanoparticles and ruthenium bipyridyl with gradual enhancement in the catalytic activity. The typical application in probing glucose oxidase catalyzed reaction based on both homogeneous and heterogeneous catalysis has been recorded. In addition the synthetic approach could also be explored to incorporate Prussian blue and palladium nanoparticles in mesoporous matrix for developing variety of PB-based devices.

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