Metal nanoparticle catalyzed cyclobutane cleavage reaction

RSC Advances ◽  
2015 ◽  
Vol 5 (122) ◽  
pp. 100722-100724 ◽  
Author(s):  
Dengtai Chen ◽  
Xijiang Han ◽  
Wen Jin ◽  
Bin Zhang
Keyword(s):  
Gold Nanoparticles ◽  
Metal Nanoparticle ◽  
Metallic Silver ◽  
Cleavage Reaction

The pyridine substituted cyclobutane cleavage reaction can be catalyzed directly by metallic silver/gold nanoparticles.

Development of ordered metal nanoparticle arrangements on solid supports by combining a green nanoparticle synthetic method and polymer templating for sensing applications

RSC Advances ◽  
2016 ◽  
Vol 6 (65) ◽  
pp. 60502-60512 ◽  
Author(s):  
M. Blanco-Loimil ◽  
A. Pardo ◽  
E. Villar-Alvarez ◽  
R. Martínez-González ◽  
A. Topete ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
High Performance ◽  
Room Temperature ◽  
Metal Nanoparticle ◽  
Synthetic Method ◽  
Solid Supports ◽  
Ordered Arrays ◽  
Sensing Applications ◽  
Polymer Templating ◽  
One Step

One step, simple, robust and "green" methodology to fabricate high-density ordered arrays of uniform gold nanoparticles and gold nanoparticles clusters at room temperature over large areas which are suitable for high-performance SERS.

scholarly journals Optimisation and Scale-up of the Synthesis of Gold Nanoparticle-Wool Fibre Composites

2021 ◽  
Author(s):  
◽  
Thomas Wade Nilsson
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Laboratory Scale ◽  
Metal Nanoparticle ◽  
Ex Situ ◽  
Wool Fibre ◽  
Reaction Conditions ◽  
Gold Colloids ◽  
Fibre Composites

<p>Gold nanoparticles are known for their remarkable optical properties; they exhibit localised surface plasmon resonance bands in the visible region of the electromagnetic spectrum. This has led to their use as luxury dyes for the colouring of wool fibres. Gold is associated with wealth and desire, and as such, gold nanoparticle-wool fibre composites may be fabricated into high-quality garments, apparel, textiles and carpets for international markets.  Novel proprietary approaches for the laboratory-scale synthesis of gold nanoparticle-wool fibre composites have previously been developed by Professor James Johnston and Dr Kerstin Lucas. The innovative nanotechnology utilises the affinity of gold for sulfur-containing cystine residues in wool fibres, to attract and bind the gold nanoparticles. One approach involves the absorption of gold ions by wool fibres and the nucleation of gold nanoparticles in-situ. In an alternative method, gold nanoparticle colloids are synthesised ex-situ, and are then used to colour wool fibres.  The reaction conditions of the in-situ and ex-situ approaches were optimised with respect to cost-effectiveness and scalability. The gold content of the in-situ composites was minimised, and the range of possible colours widened, via the use of heat and external reducing agents. In the ex-situ process, the formation and stability of the gold nanoparticle colloids was studied, and the reaction conditions of the synthesis were optimised. The rate of uptake of gold nanoparticles to wool was controlled by manipulating the pH, concentration, volume, and wool to liquor ratio of the gold colloids, and by introducing auxiliary agents into the dyeing reactions. A range of chemical treatments and alternative stabilising agents were investigated to improve the washfastness properties of ex-situ gold nanoparticle-wool fibre composites.  There are numerous size-controllable syntheses of gold nanoparticle colloids at the laboratory-scale. However, when the process is scaled-up, gold nanoparticle synthesis is no longer trivial. A barrel reactor with a high velocity mixer was utilised to achieve uniform mixing and heating in the synthesis of gold nanoparticle colloids of up to 90 L in volume. The ratios of gold to stabilising agents in the colloidal gold syntheses were optimised to result in more stable and reproducible gold colloids for subsequent dyeing reactions.  The uniform colouring of small quantities of wool is easily achieved in the laboratory, but preventing colour variation across a kilogram of wool is a significant challenge. Initial kilogram-scale dyeing reactions in static tank reactors resulted in unevenly coloured gold nanoparticle-wool fibre composites. To overcome this, conventional hank dyeing equipment was used to colour felted merino yarn, in collaboration with the wool dyeing industry. Modified hank dyeing procedures were recreated in the laboratory, and composites with remarkable colour uniformity were produced. Industrial package dyeing reactors were then used to colour fine merino yarn with gold nanoparticle colloids. The uptake of gold nanoparticles was controlled by manipulating the owrates, ow direction and amounts of auxiliary agents that were employed in the dyeing reactions.  Based upon the success of the industrial dyeing reactions, novel dyeing reactors were developed for the colouring of hanks of wool fibres and yarns in the laboratory. These reactors utilised rapid dye circulation and pressure to produce gold nanoparticle-wool fibre composites with remarkable colour uniformity. The composites were used to fabricate luxury apparel and carpets for international trade expositions.  The pathway from synthesis in the laboratory to pilot-scale production of gold nanoparticle-wool fibre composites is presented. The PhD research was an integral step in the successful commercialisation of this innovative nanotechnology, and will assist in scaling-up the synthesis of metal nanoparticle colloids and nanocomposites in the future.</p>

scholarly journals A simulation study on the effect of size gold nanoparticles on broadband light absorption in dye-sensitised solar cells

2021 ◽  
Vol 67 (3 May-Jun) ◽  
pp. 509
Author(s):  
Karwan Wasman Qadir
Keyword(s):  
Gold Nanoparticles ◽  
Solar Cells ◽  
Optical Absorption ◽  
Incident Angle ◽  
Research Work ◽  
Metal Nanoparticle ◽  
Absorption Enhancement ◽  
Difference Time ◽  
Nanoparticle Sizes

Plasmon-assisted energy conversion in dye-sensitised solar cells (DSSCs) has been achieved by applying gold (Au) nanoparticles (NPs) inside Titania (TiO2) photoanodes. Gold nanoparticles (GNPs) were introduced into DSSCs to further enhance their power conversion efficiency (PCE). In this research work, an effort has been made to enhance the optical absorption and improve the performance of DSSCs. By utilising finite-difference time-domain (FDTD) software, GNPs with radii of 15, 25, 35, 45, 55, 65, 75 and 85 nm were produced and introduced into the TiO2 photoanode. The optimum radius for the optical absorption enhancement was found to be 85 nm because the effect of plasmon coupling is more significant for metal nanoparticle sizes > 60 nm. The effect of various sizes of GNPs on light scattering has also been presented in this study. Moreover, the investigation has focused on the role of incident angle of light source on the absorption in TiO2 films. It was found that the optimum incident angle for the enhancement of broadband optical absorption in the wavelength range of 450–800 nm is 70°.

scholarly journals Megavoltage Radiosensitization of Gold Nanoparticles on Glioblastoma Cancer Cell Line Using a Clinical Platform

2019 ◽  
Author(s):  
Farasat Kazmi ◽  
Kate A. Vallis ◽  
Balamurugan A. Vellayappan ◽  
Aishwarya Bandla ◽  
Duan Yukun ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Cancer Cell Line ◽  
Radiation Sensitivity ◽  
Dark Field ◽  
Metal Nanoparticle ◽  
X Rays ◽  
Survival Fraction ◽  
Significant Difference ◽  
Vitro Model

Gold nanoparticles (GNPs) have demonstrated significant dose enhancement with kilovoltage (kV) X-rays however recent studies have shown inconsistent findings with megavoltage (MV) X-rays. We proposed to evaluate the radiosensitization effect in U87 glioblastoma (GBM) cells in the presence of 42 nm GNPs and irradiated with a clinical 6 MV photon beam. Cytotoxicity and radiosensitization was observed using MTS and clonogenic cellular radiation sensitivity assays respectively. Sensitization enhancement ratio was calculated for 2 Gy (SER2Gy) with GNP (100 &mu;g/mL). Dark field and MTS assay revealed high co-localization and good biocompatibility of the GNPs with GBM cells. Significant sensitization enhancement of 1.45 (P = 0.001) was observed with GNP 100 &mu;g/mL. Similarly, at 6 Gy there was significant difference in the survival fraction between GBM alone group (Mean (M) = 0.26, Standard Deviation (SD) = 0.008) and GBM plus GNP group (M = 0.07, SD = 0.05, P = 0.03). GNPs enable radiosensitization in U87 GBM cells at 2 Gy when irradiated using a clinical platform. In addition to the potential clinical utility of GNPs, these studies demonstrate the effectiveness of a robust and easy to standardise in-vitro model that can be employed for future studies involving metal nanoparticle plus irradiation.

Constructing Metal Nanoparticle Multilayers with Polyphenylene Dendrimer/Gold Nanoparticles via “Click” Chemistry

Langmuir ◽  
2013 ◽  
Vol 29 (12) ◽  
pp. 3943-3949 ◽  
Author(s):  
Huiqiang Li ◽  
Zhanxian Li ◽  
Linzhi Wu ◽  
Yuna Zhang ◽  
Mingming Yu ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Click Chemistry ◽  
Metal Nanoparticle

scholarly journals Hyaluronan-Metal Gold Nanoparticle Hybrids for Targeted Tumor Cell Therapy

2020 ◽  
Vol 21 (9) ◽  
pp. 3085 ◽  
Author(s):  
Vanessa Sanfilippo ◽  
Viviana Carmela Linda Caruso ◽  
Lorena Maria Cucci ◽  
Rosanna Inturri ◽  
Susanna Vaccaro ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gold Nanoparticles ◽  
Confocal Microscopy ◽  
Tumor Cell ◽  
Cancer Cells ◽  
Synthesis Method ◽  
Human Tumor ◽  
Metal Nanoparticle ◽  
Cell Models ◽  
Microscopy Imaging

In this study, a novel multifunctional nanoplatform based on core-shell nanoparticles of spherical gold nanoparticles (AuNPs) capped with low and high molecular weight (200 and 700 kDa) hyaluronic acid (HA), was assembled via a green, one-pot redox synthesis method at room temperature. A multitechnique characterization approach by UV-visible spectroscopy, dynamic light scattering and atomic force microscopy pointed to the effective ‘surface decoration’ of the gold nanoparticles by HA, resulting in different grafting densities of the biopolymer chains at the surface of the metal nanoparticle, which in turn affected the physicochemical properties of the nanoparticles. Specifically, the spectral features of the gold plasmonic peak (and the related calculated optical size), the hydrodynamic diameter and the nanoparticle stability were found to depend on the molecular weight of the HA. The CD44-targeting capability of HA-functionalized gold nanoparticles was tested in terms of antibacterial activity and cytotoxicity. An enhanced inhibitory activity against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus was found, with a HA molecular weight (MW)-dependent trend for the HA-capped AuNPs compared to the bare, glucose-capped AuNPs. Cell viability assays performed on two CD44-positive cell models, namely normal human umbilical vein endothelial (HUVEC) and prostate tumor (PC-3) cells, in comparison with neuroblastoma cells (SH-SY5Y), which do not express the CD44 receptor, demonstrated an increased cytotoxicity in neuroblastoma compared to prostate cancer cells upon the cellular treatments by HA–AuNP compared to the bare AuNP, but a receptor-dependent perturbation effect on cytoskeleton actin and lysosomal organelles, as detected by confocal microscopy. These results highlighted the promising potentialities of the HA-decorated gold nanoparticles for selective cytotoxicity in cancer therapy. Confocal microscopy imaging of the two human tumor cell models demonstrated a membrane-confined uptake of HA-capped AuNP in the cancer cells that express CD44 receptors and the different perturbation effects related to molecular weight of HA wrapping the metallic core of the plasmonic nanoparticles on cellular organelles and membrane mobility.

PEGylated Gold Nanoparticles Functionalized with β-Cyclodextrin Inclusion Complexes: Towards Metal Nanoparticle - Polymer - Carbohydrate Cluster Biohybrid Materials

2010 ◽  
Vol 63 (8) ◽  
pp. 1245 ◽  
Author(s):  
Jingquan Liu ◽  
Eki Setijadi ◽  
Yingkai Liu ◽  
Michael R. Whittaker ◽  
Cyrille Boyer ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Raft Polymerization ◽  
Gold Surface ◽  
Attenuated Total Reflection ◽  
Metal Nanoparticle ◽  
Surface Plasmon Resonance Analysis ◽  
Resonance Analysis ◽  
Cyclodextrin Inclusion Complexes ◽  
Reversible Addition ◽  
Raft Agent

A cholesterol-functional trithiocarbonate reversible addition–fragmentation chain transfer (RAFT) agent was synthesized and employed to generate well-defined poly(polyethylene glycol) acrylate with cholesterol chain termini using RAFT polymerization. Subsequently, the polymers were grafted onto the surface of gold nanoparticles using the trithiocarbonate functionality to bind to the gold surface. The cholesterol moieties were then modified via complexation with β-cyclodextrin. The step-by-step modification of gold nanoparticles was characterized by dynamic light scattering, attenuated total reflection infrared spectroscopy and surface plasmon resonance analysis.

scholarly journals Effect of Polyvinyl Alcohol Ligands on Supported Gold Nano-Catalysts: Morphological and Kinetics Studies

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 879
Author(s):  
Stefano Scurti ◽  
Eleonora Monti ◽  
Elena Rodríguez-Aguado ◽  
Daniele Caretti ◽  
Juan Antonio Cecilia ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Polyvinyl Alcohol ◽  
Photoelectron Spectroscopy ◽  
Catalytic Mechanism ◽  
Weight Ratio ◽  
Metal Nanoparticle ◽  
X Ray ◽  
Nano Catalysts ◽  
Supported Gold

The effect of polyvinyl alcohol (PVA) stabilizers and gold nanoparticles supported on active carbon (AuNPs/AC) was investigated in this article. Polymers with different molecular weights and hydrolysis degrees have been synthesized and used, like the stabilizing agent of Au nano-catalysts obtained by the sol-immobilization method. The reduction of 4-nitrophenol with NaBH4 has been used as a model reaction to investigate the catalytic activity of synthesized Au/AC catalysts. In addition, we report several characterization techniques such as ultraviolet-visible spectroscopy (UV-Vis), dynamic light scattering (DLS), X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) in order to correlate the properties of the polymer with the metal nanoparticle size and the catalytic activity. A volcano plot was observed linking the catalytic performance with hydrolysis degree and the maximum of the curve was identified at a value of 60%. The Au:PVA-60 weight ratio was changed in order to explain how the amount of the polymer can influence catalytic properties. The effect of nitroaromatic ring substituents on the catalytic mechanism was examined by the Hammett theory. Moreover, the reusability of the catalyst was investigated, with little to no decrease in activity observed over five catalytic cycles. Morphological and kinetic studies reported in this paper reveal the effect of the PVA polymeric stabilizer properties on the size and catalytic activity of supported gold nanoparticles.

scholarly journals Plasmonic coupling induced by growing processes of metal nanoparticles in wrinkled structures and driven by mechanical strain applied to a polidimethisiloxisilane template

2017 ◽  
Vol 9 (2) ◽  
pp. 45 ◽  
Author(s):  
Cataldi Ugo ◽  
Buergi Thomas
Keyword(s):  
Gold Nanoparticles ◽  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Self Assembly ◽  
Metal Nanoparticle ◽  
Plasmon Coupling ◽  
Bottom Up ◽  
Mechanical Control ◽  
Plasmonic Coupling

We report the mechanical control of plasmonic coupling between gold nanoparticles (GNPs) coated onto a large area wrinkled surface of an elastomeric template. Self-assembly and bottom-up procedures, were used to fabricate the sample and to increase the size of GNPs by exploiting the reduction of HAuCl4 with hydroxylamine. The elastic properties of template, the increase of nanostructure size joined with the particular grating configuration of the surface have been exploited to trigger and handle the coupling processes between the nanoparticles. Full Text: PDF ReferencesG. Mie, "Beiträge zur Optik trüber Medien, speziell kolloidaler Metallösungen", Ann. Phys. 25, 377 (1908) CrossRef U. Kreibig and M. Vollmer, Optical properties of metal cluster, Berlin 1995 CrossRef S. A. Maier, Plasmonics: Fundamentals and Applications, Springer, New York, 2007 CrossRef L. A. Lane, X. Qian, and S. Nie, "SERS Nanoparticles in Medicine: From Label-Free Detection to Spectroscopic Tagging", Chem. Rev. 115, 10489-10529 (2015) CrossRef N. Pazos-Perez, W. Ni, A. Schweikart, R. A. Alvarez-Puebla, A. Fery and L. M. Liz-Marzan, "Highly uniform SERS substrates formed by wrinkle-confined drying of gold colloids", Chem. Sci. 1, 174-178P (2010) CrossRef M. Aioub and M. A. El-Sayed, "A Real-Time Surface Enhanced Raman Spectroscopy Study of Plasmonic Photothermal Cell Death Using Targeted Gold Nanoparticles", J. Am. Chem. Soc. 138, 1258-1264 (2016) CrossRef G. Baffou, and R. Quidant, "Thermo-plasmonics: using metallic nanostructures as nano-sources of heat", Laser Photonics Rev. 7, No. 2, 171-187 (2013) CrossRef G. Palermo, U. Cataldi, L. De Sio, T. Beurgi, N. Tabiryan, and C. Umeton, "Optical control of plasmonic heating effects using reversible photo-alignment of nematic liquid crystals", Applied Physics 109, 191906 (2016) CrossRef J. R. Dunklin, G. T. Forcherio, K. R. Berry, Jr., and D. K. Roper, "Gold Nanoparticle Polydimethylsiloxane Thin Films Enhance Thermoplasmonic Dissipation by Internal Reflection", J. Phys. Chem. 118, 7523-7531 (2014) CrossRef Y. Jin, "Engineering Plasmonic Gold Nanostructures and Metamaterials for Biosensing and Nanomedicine", Adv. Mater. 24, 5153-5165 (2012) CrossRef J. H. Lee, Q. Wu, and W. Park, "Metal nanocluster metamaterial fabricated by the colloidal self-assembly", Optics Letters 34, Issue 4, 443-445 (2009) CrossRef R. Pratibha, K. Park, I. I. Smalyukh, and W. Park, "Tunable optical metamaterial based on liquid crystal-gold nanosphere composite", Optics Express 17, Issue 22, 19459-19469 (2009) CrossRef J. Dintinger, S. Mühlig, C. Rockstuhl, and T. Scharf, "A bottom-up approach to fabricate optical metamaterials by self-assembled metallic nanoparticles", Optical Materials Express 2, Issue 3, 269-278 (2012) CrossRef T. Maurer, J. Marae-Djouda, U. Cataldi, A. G., Guillaume Montay, Y. Madi, B. Panicaud, D. Macias, P.-M. Adam, G. Léveque, T. Buergi, and R. Caputo, "The beginnings of plasmomechanics: towards plasmonic strain sensors", Front. Mater. Sci. 9(2) (2015) CrossRef J. N. Anker W. P. Hall, O. Lyandres, N. C. Shah, J. Zhao and R. P. Van Duyne, "Biosensing with plasmonic nanosensors", Nature Materials 7, 442 - 453 (2008) CrossRef M. E. Stewart, C. R. Anderton, L. B. Thompson, J. Maria, S. K. Gray, J. A. Rogers,and R. G. Nuzzo, "Nanostructured Plasmonic Sensors", Chem. Rev. 108, 494-521 (2008) CrossRef P. K. Jain , M. A. El-Sayed, "Plasmonic coupling in noble metal nanostructures", Chemical Physics Letters 487, 153-164 (2010) CrossRef P. K. Jain, W. Huang and M. A. El-Sayed, "On the Universal Scaling Behavior of the Distance Decay of Plasmon Coupling in Metal Nanoparticle Pairs: A Plasmon Ruler Equation", Nano Letters 7, 2080-2088 (2007) CrossRef U. Cataldi, R. Caputo, Y. Kurylyak, G. Klein, M. Chekini, C. Umeton and T. Buergi, "Growing gold nanoparticles on a flexible substrate to enable simple mechanical control of their plasmonic coupling", Journal of Materials Chemistry C 2(37), 7927-7933 (2014). CrossRef S. K. Ghosh and T. Pal, "Interparticle Coupling Effect on the Surface Plasmon Resonance of Gold Nanoparticles: From Theory to Applications", Chem. Rev. 107, 4797 (2007) CrossRef M. K. Kinnan and G. Chumanov, "Plasmon Coupling in Two-Dimensional Arrays of Silver Nanoparticles: II. Effect of the Particle Size and Interparticle Distance", J. Phys. Chem. C 114, 7496 (2010) CrossRef X. L. Zhu, S. S. Xiao, L. Shi, X. H. Liu, J. Zi, O. Hansen and N. A. Mortensen, "A stretch-tunable plasmonic structure with a polarization-dependent response", Opt. Express, 20, 5237 (2012) CrossRef K. H. Su, Q. H. Wei, X. Zhang, J. J. Mock, D. R. Smith and S. Schultz, "Interparticle Coupling Effects on Plasmon Resonances of Nanogold Particles", Nano Lett. 3, 1087 (2003) CrossRef Y. L. Chiang, C. W. Chen, C. H. Wang, C. Y. Hsieh, Y. T. Chen, H. Y. Shih and Y. F. Chen, "Mechanically tunable surface plasmon resonance based on gold nanoparticles and elastic membrane polydimethylsiloxane composite", Appl. Phys. Lett. 96, 041904 (2010) CrossRef N. Bowden, W. T. S. Huck, K. E. Paul, and G. M. Whitesides, "The controlled formation of ordered, sinusoidal structures by plasma oxidation of an elastomeric polymer", Appl. Phys. Lett. 75(17) (1999) CrossRef R, A. Lawton, C. R. Price, A. F. Runge, Walter J. Doherty III, S. Scott Saavedra , "Air plasma treatment of submicron thick PDMS polymer films: effect of oxidation time and storage conditions", Colloids and Surfaces A: Physicochem. Eng. Aspects 253, 213-215 (2005). CrossRef A Schweikart, N. Pazos-Perez, R. A. Alvarez-Puebla and A. Fery, "Controlling inter-nanoparticle coupling by wrinkle-assisted assembly", Soft Matter 7, 4093 (2011) CrossRef K. R. Brown, L. A. Lyon, A. P. Fox, B. D. Reiss and M. J. Natan, "Hydroxylamine Seeding of Colloidal Au Nanoparticles. 3. Controlled Formation of Conductive Au Films", Chem. Mater. 12, 314 (2000) CrossRef

Sign in / Sign up

Export Citation Format

Share Document