Download or read book Establishing the Quality of Molecular Coatings on Gold Nanoparticles written by Idah C. Pekcevik and published by . This book was released on 2014 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: The surface chemistry of nanoparticles imparts colloidal stability to nanoparticles by acting as barriers between their surrounding environment and the nanoparticles. Gold nanoparticles (AuNPs) are an ideal platform for many studies because of localized surface plasmon resonant properties, chemical stability, and the relative ease of modifying their surfaces with a wide variety of molecular coatings (e.g., alkanethiolates). Understanding and improving the physicochemical stability of these surface-modified nanoparticles is essential for their reproducible use in each application. The long-term colloidal stability of AuNPs relies on the resistance of their surface modifications to thermal degradation, chemical attack and oxidizing conditions. For this purpose, my research has been focused on determining the quality of molecular coatings on gold nanoparticles, and developing techniques, which are complementary to each other, to assess the quality factor of these coatings. Gold nanoparticles with varied qualities of molecular coatings were prepared and tested for their relative stabilities under various physical (e.g., temperature, time, laser irradiation) and chemical (e.g., in presence of metal etchants) conditions. We found that the quality of molecular coatings on AuNPs depends on the process conditions such as solution composition (e.g., the presence of co-surfactants, concentration of excess surfactants), density of capping molecules, and process time, used to form these coatings. We found that higher quality molecular coatings on the gold colloids increased the chances that the particles would remain stable over the over the duration of their intended use. Those colloids modified with relatively higher quality self-assembled monolayers were also more resistant to cyanide etching. These results highlight the importance of methodology for preparing high quality monolayers on nanoparticles and testing their ability to remain stable over the duration of their intended use, for example, during photothermal processes. In addition, the loading of DNA molecules onto AuNPs was tuned to achieve varying densities of DNA, and through this work, achieved the highest reported loading of single-stranded DNA (ss-DNA) molecules on gold nanorods. These high loadings of DNA oligonucleotides could enable a high loading of therapeutics onto the nanorods, which could translate into a higher or more prolonged delivery of therapeutic doses when actived by photothermal or other processes.
Download or read book Molecular Dynamics Study of Alkanethiolate Self Assembled Monolayer Coated Gold Nanoparticle written by and published by . This book was released on 2007 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Through molecular simulations we have observed that the surface of gold nanoparticles become highly corrugated by the adsorption of alkanethiolate self assembled monolayers (SAMs). Furthermore, as the temperature is increased, the SAMs dissolve into the gold nanoparticle, creating a liquid mixture at temperatures much lower than the melting temperature of the gold nanoparticle. By analyzing the mechanical and chemical properties of gold nanoparticles at temperatures below the melting point of gold, with different SAM chain lengths and surface coverage properties, we have determined that the system is metastable. The model and computational results that provide support for this hypothesis are presented in this paper.
Download or read book Gold Nanoparticles written by Mohammed Muzibur Rahman and published by BoD – Books on Demand. This book was released on 2019-02-13 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gold Nanoparticles - Reaching New Heights contains recent research on the preparation, characterization, fabrication, and potential of optical and biological applications of gold nanoparticles (AuNPs). It is promising novel research that has received a lot of interest over the last few decades. It covers advanced topics on optical, physical, medicinal, and biological applications of AuNPs. Development of green nanotechnology is generating the interest of researchers towards the synthesis of eco-friendly, safe, non-toxic applications, which can be used for manufacture at a large scale. These are simple, cost-effective, stable, enduring, and reproducible aqueous room temperature synthesis applications to obtain the self-assembly of AuNPs. This potentially unique work offers various approaches to R
Download or read book Gold Nanoparticles For Physics Chemistry And Biology Second Edition written by Catherine Louis and published by World Scientific. This book was released on 2017-06-02 with total page 681 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gold Nanoparticles for Physics, Chemistry and Biology offers an overview of recent research into gold nanoparticles, covering their discovery, usage and contemporary practical applications.This Second Edition begins with a history of over 2000 years of the use of gold nanoparticles, with a review of the specific properties which make gold unique. Updated chapters include gold nanoparticle preparation methods, their plasmon resonance and thermo-optical properties, their catalytic properties and their future technological applications. New chapters have been included, and reveal the growing impact of plasmonics in research, with an introduction to quantum plasmonics, plasmon assisted catalysis and electro-photon conversion. The growing field of nanoparticles for health is also addressed with a study of gold nanoparticles as radiosensibiliser for radiotherapy, and of gold nanoparticle functionalisation. This new edition also considers the relevance of bimetallic nanoparticles for specific applications.World-class scientists provide the most up-to-date findings for an introduction to gold nanoparticles within the related areas of chemistry, biology, material science, optics and physics. It is perfectly suited to advanced level students and researchers looking to enhance their knowledge in the study of gold nanoparticles.
Download or read book Update on Gold Nanoparticles written by Valerio Voliani and published by Smithers Rapra. This book was released on 2013-01-29 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last decade, gold nanoparticles have provided a suitable platform for the development of novel and efficient diagnostic and therapeutic tools, which avoid the typical drawbacks of the old systems. They are biocompatible and they can be easily synthesised, encapsulated and functionalised with (bio)molecules. Nanoparticles produced by a wet chemistry synthesis have the geometry, which enables the complete control of their optical and physical properties. It is also possible to influence the targeting and stability/release behaviour by coating the nanoparticle surface. In this Update the reader can find in a single volume the methods used most often for the synthesis and coating of gold nanoparticles (spheres, cages, cubes, rods), the links between optical features and geometries of gold nanoparticles, and the novel applications in nanomedicine of gold nanoparticles determined by their geometry. One of the main objectives of this Update is to provide, a readily comprehensible connection in all the chapters between the geometry of gold nanoparticles and their final applications. Another target of this book is to provide information about efficient processes for the synthesis and the coating of gold nanoparticles, all of which have been directly tested by the author. This Update offers comprehensive information on the whole topic from the synthesis of the gold nanoparticles to their medical applications; this is accompanied by a complete and recent bibliography, in order to give to the readers the opportunity to research further the topics addressed in the book. In this way, students and researchers from academia and industry can have a complete picture of gold nanostructures, physicians and biologists can develop ideas and applications for the new nano-tools, and chemists can have a general guide to the synthesis of gold nanoparticles. This is a state-of-the-art guide for the synthesis and uses of gold nanoparticles.
Download or read book Molecular Simulations of Gold Nanoparticles Coated With Self Assembled Alkanethiolate Monolayers written by and published by . This book was released on 2006 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to utilize the novel electrical, magnetic, optical, and physical properties of coated metal nanoparticles, one must be able to efficiently predict the nanoparticle size-dependent properties and to fabricate consistently sized nanoparticles. Both of these goals can be obtained through the use of numerical simulation. In this work the gold nanoparticle and nanoparticle/self-assembled monolayer systems have been analyzed with a physically accurate and computationally efficient numerical simulation. The simulation model and method are described in the following paper.
Download or read book Gold Nanoparticles written by Valerio Voliani and published by Walter de Gruyter GmbH & Co KG. This book was released on 2020-04-20 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gold nanoparticles provide a platform for the development of new and efficient diagnostic and therapeutic tools.This book offers a general guide to the synthesis and coating of gold nanoparticles. It describes the links between optical features and geometries of gold nanoparticles and provides a readily comprehensible connection in all the chapters between the geometry of gold nanoparticles and their final applications.
Download or read book Immunosensors written by Minhaz Uddin Ahmed and published by Royal Society of Chemistry. This book was released on 2019-08-28 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Immunosensors are widely used and are particularly important for fast diagnosis of diseases in remote environments as well as point-of-care devices. In this book, expert scientists are covering a selection of high quality representative examples from the past five years explaining how this area has developed. It is a compilation of recent advances in several areas of immunosensors for multiple target analysis using laboratory based or point-of-care set-up, for example graphene-, ISFET- and nanostructure-based immunosensors, electrochemical magneto immunosensors and nanoimprinted immunosensors. Filling a gap in the literature, it showcases the multidisciplinary, innovative developments in this highly important area and provides pointers towards commercialisation. Delivering a single, comprehensive work, it appeals to graduate students and professional researchers across academia and industry.
Download or read book Understanding Shape Control in Gold Nanoparticles from Molecular Dynamics Simulations written by Santosh Kumar Meena and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assembly of Gold Nanoparticles by Ribosomal Molecular Machines written by Ioana Simona Pavel and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular Engineering of Gold Nanorod Surfaces Towards Improved Physical Properties and Understanding Nanoparticle cell Interactions written by Alaaldin M. Alkilany and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Gold nanorods have unique optical properties and various promising applications. Wet chemical synthesis of gold nanorods requires the use of cetyl trimethylammonium bromide (CTAB) as shape-directing surfactant, which form a bilayer on the surfaces of gold nanorods. CTAB bilayer stabilizes the nanorods against aggregation and has the ability to sequester organic molecules from aqueous bulk. CTAB molecules in the bilayer are held via weak hydrophobic forces and thus tend to desorb resulting in nanorods aggregation and toxicity to cultured cells. Herein, three surface-engineering approaches to enhance the colloidal physical stability and biocompatibility of gold nanorods have been examined: 1) electrostatic approach via overcoating with polyelectrolytes; 2) covalent approach via surfactant polymerization; 3) and hydrophobic approach via cholesterol insertion into the bilayer. Layer-by-layer coating has been used to overcoat CTAB-capped nanorods with both negatively and positively charged polyelectrolytes. Compared to CTAB-capped nanorods, polyelectrolyte-coated gold nanorods showed improved stability against aggregation in culture medium and enhanced biocompatibility to cultured cells. The toxicity of CTAB-capped gold nanorod solutions was assigned quantitatively to free CTAB molecules, where gold nanorods themselves were found not toxic. Similar biocompatibility profiles for both cationic and anionic coated-gold nanorods were observed due to spontaneous protein adsorption. In growth media, all examined nanorods were covered with protein corona and thus bear similar negative effective surface charge explaining their similar toxicity profiles. ! """! ! Our covalent approach to stabilize the surfactant bilayer on the surface of gold nanorods relies on synthesizing a polymerizable version of the CTAB, which we have used to prepare gold nanoparticles (both spheres and rods). Surfactant polymerization on the surface of gold nanoparticles was found to retard surfactant desorption and thus enhance both stability against aggregation and biocombatibility of these nanomaterials. The hydrophobic approach to stabilize the CTAB bilayer on gold nanorods relies on using a bilayer-condensing agent such as cholesterol to increase the total hydrophobic interactions. Cholesterol is known to consist of up to 50% of mammalian cell membrane0́9s total lipids, and thus have important effect on their stability and physical properties. Using cholesterol-rich growth medium, we have prepared gold nanorods with excellent size and shape distribution. The prepared gold nanorods in the presence of cholesterol have a significantly higher surface charge and exhibit superior stability against aggregation compared to the nanorods prepared without cholesterol. In addition to the enhanced aqueous stability and biocompatibility, stabilization the CTAB bilayer on the surface of gold nanorods have allowed for suspension gold nanorods in organic solvents without aggregation. Polyelectrolyte-coated gold nanorods showed remarkable stability in polar organic solvents against aggregation as compared to CTAB-capped nanorods. The suspendability of coated-gold nanorods in polar organic solvents facilitates the incorporation of these nanomaterials into hydrophobic polymers and thus fabrication of thin films that contain uniform gold nanorod dispersions (nanocomposites).
Download or read book Gold Nanoparticles Explore Cells written by Anna Hûfner and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Interplay of Gold Nanoparticles and Small Molecules written by Ye Yang and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts written by and published by . This book was released on 1998 with total page 1076 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of Inorganic Nanomaterials written by Sneha Bhagyaraj and published by Woodhead Publishing. This book was released on 2018-06-29 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthesis of Inorganic Nanomaterials: Advances and Key Technologies discusses the latest advancements in the synthesis of various types of nanomaterials. The book's main objective is to provide a comprehensive review regarding the latest advances in synthesis protocols that includes up-to-date data records on the synthesis of all kinds of inorganic nanostructures using various physical and chemical methods. The synthesis of all important nanomaterials, such as carbon nanostructures, Core-shell Quantum dots, Metal and metal oxide nanostructures, Nanoferrites, polymer nanostructures, nanofibers, and smart nanomaterials are discussed, making this a one-stop reference resource on research accomplishments in this area. Leading researchers from industry, academia, government and private research institutions across the globe have contributed to the book. Academics, researchers, scientists, engineers and students working in the field of polymer nanocomposites will benefit from its solutions for material problems. - Provides an up-to-date data record on the synthesis of all kinds of organic and inorganic nanostructures using various physical and chemical methods - Presents the latest advances in synthesis protocols - Includes the latest techniques used in the physical and chemical characterization of nanomaterials - Covers the characterization of all the important materials groups, such as carbon nanostructures, core-shell quantum dots, metal and metal oxide nanostructures, Nano ferrites, polymer nanostructures and nanofibers
Download or read book Postharvest Management Approaches for Maintaining Quality of Fresh Produce written by Mohammed Wasim Siddiqui and published by Springer. This book was released on 2016-02-24 with total page 233 pages. Available in PDF, EPUB and Kindle. Book excerpt: The volume presents existing and novel management approaches that are in use or have a great potential to be used to maintain the postharvest quality of fresh produce in terms of microbiological safety, nutrition, and sensory quality. In comparison to traditional synthetic chemicals, these eco-friendly molecules are equally effective with respect to slowing the physiological and biochemical changes in harvested produce. Application of terpenic compounds, phenolic compounds, salicylic acid, methyl jasmonates, hydrogen peroxide, ethanol, sulphur compounds, polyamines, plant growth regulators, active carbohydrates, ozone, hexanal and nitric oxide have been proven effective in minimizing storage disorders like chilling injury, scald, fungal diseases like stem-end rot, blue mould rot, green mould rot, anthracnose, regulation of ripening and senescence, etc. This book will be a standard reference work for the management of shelf life in the fresh produce industry.
Download or read book Metals Abstracts Index written by and published by . This book was released on 1995 with total page 1596 pages. Available in PDF, EPUB and Kindle. Book excerpt:
