Monalayer Arrangement of Pt Nanoparticles

1998 ◽  
Vol 4 (S2) ◽  
pp. 738-739
Author(s):  
T. C. Green ◽  
J. M. Petroski ◽  
Z. Wang ◽  
M. El-Sayed
Keyword(s):  
Metallic Nanoparticles ◽  
Solid Phase ◽  
Pt Nanoparticles ◽  
Self Assembled Monolayers ◽  
3 Dimensional ◽  
Assembled Monolayers ◽  
Potential Applications ◽  
Shape Controlled ◽  
Superlattice Structures ◽  
Catalyzed Reactions

Formation of metallic nanoparticles produces an increased surface area per unit volume of material, which provides potential applications in enhancing surface catalyzed reactions. Recently, attention has been focused on moving from the solution based syntheses to solid phase materials by arranging such particles into well ordered 2- and 3- dimensional structures, or forming cluster engineered materials that posses well defined structures. Such studies have shown the importance of size, size distribution, and shape of particles upon self assembled monolayers. We have recently prepared shape-controlled Pt nanoparticles with ﹛111﹜ (tetrahedral), ﹛100﹜ (cubic), and mixed ﹛111﹜ - ﹛100﹜ (truncated octahedral) faces. To study how these faces may orient to form particle point superlattice structures we have prepared monolayer distributions of Pt particles in humidity chambers for analysis by TEM.Our shape controlled Pt particle synthesis yields between 60 and 80 % cubes, tetrahedra, or truncated octahedra with average diameters ≥ 7 nm.

scholarly journals Antifouling (Bio)materials for Electrochemical (Bio)sensing

2019 ◽  
Vol 20 (2) ◽  
pp. 423 ◽  
Author(s):  
Susana Campuzano ◽  
María Pedrero ◽  
Paloma Yáñez-Sedeño ◽  
José Pingarrón
Keyword(s):  
Metallic Nanoparticles ◽  
Self Assembled Monolayers ◽  
Electrochemical Activation ◽  
Reaction Products ◽  
Diverse Range ◽  
Prolonged Incubation ◽  
Practical Applications ◽  
Electrochemical Biosensing ◽  
Redox Couples ◽  
Assembled Monolayers

(Bio)fouling processes arising from nonspecific adsorption of biological materials (mainly proteins but also cells and oligonucleotides), reaction products of neurotransmitters oxidation, and precipitation/polymerization of phenolic compounds, have detrimental effects on reliable electrochemical (bio)sensing of relevant analytes and markers either directly or after prolonged incubation in rich-proteins samples or at extreme pH values. Therefore, the design of antifouling (bio)sensing interfaces capable to minimize these undesired processes is a substantial outstanding challenge in electrochemical biosensing. For this purpose, efficient antifouling strategies involving the use of carbon materials, metallic nanoparticles, catalytic redox couples, nanoporous electrodes, electrochemical activation, and (bio)materials have been proposed so far. In this article, biomaterial-based strategies involving polymers, hydrogels, peptides, and thiolated self-assembled monolayers are reviewed and critically discussed. The reported strategies have been shown to be successful to overcome (bio)fouling in a diverse range of relevant practical applications. We highlight recent examples for the reliable sensing of particularly fouling analytes and direct/continuous operation in complex biofluids or harsh environments. Opportunities, unmet challenges, and future prospects in this field are also pointed out.

Nonlinear Optical Microscopy for Imaging Patterned Self-Assembled Monolayers

1996 ◽  
Vol 440 ◽  
Author(s):  
L. Smilowitz ◽  
Q.X. Jia ◽  
X. Yang ◽  
D.Q. Li ◽  
D. McBranch ◽  
...  
Keyword(s):  
Nonlinear Optical ◽  
Second Harmonic ◽  
Self Assembled Monolayers ◽  
Optical Technique ◽  
Nonlinear Optical Microscopy ◽  
Surface Sensitivity ◽  
Surfaces And Interfaces ◽  
Assembled Monolayers ◽  
Potential Applications ◽  
Self Assembled

AbstractWe have used the inherent surface sensitivity of second harmonic generation (SHG) to develop an instrument for nonlinear optical (NLO) microscopy of surfaces and interfaces. This optical technique is ideal for imaging nanometer thick self-assembled monolayers (SAM's) which have been patterned using photolithographic techniques. In this paper we demonstrate the application of SHG microscopy to patterned SAM's of the noncentrosymmetric molecule calixarene and discuss other potential applications for this new technique.

Self-Assembled Monolayers: Assembling, Disassembling and Reassembling Studies Using Afm

1999 ◽  
Vol 5 (S2) ◽  
pp. 964-965
Author(s):  
B.R.A. Neves ◽  
M. E. Salmon ◽  
D.N. Leonard ◽  
P.E. Russell ◽  
E.B. Troughton
Keyword(s):  
Double Layers ◽  
Self Assembled Monolayers ◽  
Adhesion Promoters ◽  
Force Microscopy ◽  
Atomic Force ◽  
Assembled Monolayers ◽  
Potential Applications ◽  
Self Assembled ◽  
Initial Deposition ◽  
Formation Of Groups

Self-assembled monolayers (SAM) and multilayers of organic materials have been intensely studied in the past years, due to their numerous potential applications as, for example, lubricants, corrosioninhibitors and/or adhesion-promoters [1,2]. In this talk, we will present results of several studies carried out using Atomic Force Microscopy to investigate octadecylphosphonic acid (OPA) SAM deposited on mica. We have assessed various mechanisms of assembling, disassembling and reassembling the SAM on mica. The SAM deposition method employed in this work was drip coating using an OPA solution. We have used two different solvents, which exhibit very different OPA solubility, in this work: ethanol and trihydrofuran (THF). Regarding the assembling studies, we will show the formation of groups of OPA double-layers as the initial deposition stage (deposition time < 2 seconds) when using ethanol-based solutions. We will also show that annealing such samples at 60°C produces, favorably, OPA quadruple-layers, as shown in figures la and lb, respectively.

Surface Absorption of Monolayers

MRS Bulletin ◽  
1995 ◽  
Vol 20 (6) ◽  
pp. 46-51 ◽  
Author(s):  
Abraham Ulman
Keyword(s):  
Self Assembled Monolayers ◽  
Surface Absorption ◽  
Solvent Interactions ◽  
Wear Protection ◽  
Fundamental Understanding ◽  
Assembled Monolayers ◽  
Potential Applications ◽  
Clean Metal Surface ◽  
Moisture Sensitive ◽  
Clean Metal

When the first paper describing the formation of self-assembled monolayers (SAMs) of octadecyltrichlorosilane [CH3(CH2)17SCl3, or OTS] by adsorption on SiO2 was published, it could not have been predicted that this area of research would become so important in only one decade. Although Zisman was the first to discover that monolayers can be prepared by adsorption of a surfactant onto a clean metal surface, the real revolution in the field occurred when Nuzzo and Allara showed that SAMs of alkanethiolates on gold can be prepared by adsorption of di-n-alkyl disulfides from dilute solutions. A decrease in the use of moisture-sensitive alkyl trichlorosilanes and the increased use of crystalline gold surfaces were two important reasons for the success of these SAMs. Indeed, monolayers of alkanethiolates on gold are the most studied SAMs to date and thus deserve the most detailed discussion.SAMs have been intensively studied in the past few years because of their relevance to science and technology. Due to their dense and stable structure, SAMs have potential applications in corrosion prevention, wear protection, and biosensing, for example. The ability to tailor both head and tail groups of the constituent molecules makes them ideal for gaining a more fundamental understanding of phenomena affected by competing intermolecular, molecular-substrate, and molecule-solvent interactions like ordering and growth, wetting adhesion, lubrication, and corrosion.

Application of Self-Assembled Monolayers in the Preparation of Solid-Phase Microextraction Coatings

2011 ◽  
Vol 74 (5-6) ◽  
pp. 421-427 ◽  
Author(s):  
Ali Mehdinia ◽  
Ali Ahmad Mohammadi ◽  
Saied Saeed Hosseiny Davarani ◽  
Mohammad Hossein Banitaba
Keyword(s):  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Self Assembled

Imaging Self-Assembled Monolayers: a Comparative Study Between AFM and Field-Emission SEM

1999 ◽  
Vol 5 (S2) ◽  
pp. 324-325
Author(s):  
P.E. Russell ◽  
B.R.A. Neves ◽  
M. E. Salmon ◽  
E.B. Troughton
Keyword(s):  
Self Assembled Monolayers ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Adhesion Promoters ◽  
Reduced Height ◽  
Scanning Area ◽  
Assembled Monolayers ◽  
Potential Applications ◽  
Potential Applicability ◽  
Self Assembled

Self-assembled monolayers (SAM) and multilayers of organic materials have been intensely studied in the past years, due to their numerous potential applications as, for example, lubricants, corrosioninhibitors and/or adhesion-promoters [1,2]. Due to the reduced height of SAM, typically a couple of nanometers, the various Scanning Probe Microscopy (SPM) techniques, especially Scanning Tunneling Microscopy (STM) and Atomic Force Microscopy (AFM), have been the tools of choice in the morphological and structural study of those systems [1,2]. However, these SPM techniques have some limitations. One of them is the reduced scanning area, preventing the assessment of SAM coverage in large substrate areas, which is one of the key issues in studies of the potential applicability of SAM. Furthermore, due to their imaging principle, the SPM techniques are not suited to analyze SAM on substrates where the roughness is of the order of hundreds of nanometers or higher, impeding their application on most non-ideal (atomically flat) substrates.

Shape-Controlled Syntheses of Silver Nanoparticles: Role of the Seeds

2010 ◽  
Vol 654-656 ◽  
pp. 2402-2405 ◽  
Author(s):  
Chu Yang Chen ◽  
Xu Chuan Jiang ◽  
Shi Xian Xiong ◽  
Ai Bing Yu
Keyword(s):  
Silver Nanoparticles ◽  
Metallic Nanoparticles ◽  
Chemical Properties ◽  
Biochemical Sensors ◽  
Oxidative Etching ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Heating Treatment ◽  
Potential Applications ◽  
Shape Controlled

Precious metallic nanoparticles have attracted considerable attention because of their unique properties (optical, electronic, and chemical properties) and potential applications in many areas such as optical probes, biochemical sensors, and surface enhanced Raman Spectrum. Despite many successes in synthesis of anisotropic nanoparticles (rods, plates), some limitations still exist in generating monodispersed silver nanoparticles. This study intends to elucidate the influence of crystalline seeds on the shape, size, and size distribution of nanoparticles through a seed-mediated method. The crystalline seeds can be modified by using different ways, such as heating treatment and oxidative etching. The shape and size of the generated particles will be characterized by TEM, and the particle formation and growth is tracked by UV-vis spectrometry. The findings would be useful for the shape-controlled synthesis of metal nanoparticles for desired functional properties.

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