Search results for " Gold"
showing 10 items of 278 documents
Epoxidation of stilbene using supported gold nanoparticles: cumyl peroxyl radical activation at the gold nanoparticle surface.
2014
The catalytic epoxidation of cis-stilbene using cumene as a solvent in the presence of supported gold nanoparticles (AuNP) yields a mixture of cis and trans-stilbene oxides. EPR and product distribution studies support a new mechanistic proposal where oxygen centred radicals activate the AuNP surface and form active surface oxygen species responsible for the epoxidation products.
Insights into the Mechanism of Cumene Peroxidation Using Supported Gold and Silver Nanoparticles
2013
Due to the considerable industrial implications, an in-depth study of cumene peroxidation using supported gold and silver nanoparticles was carried out to gain more insight into the mechanism of this reaction. Supported gold nanoparticles were found to efficiently catalyze the decomposition of cumene hydroperoxide with a selectivity of 25% at 80 °C when using gold supported on hydrotalcite (AuNP@HT), and 2-phenyl-2-propanol (i.e., cumyl alcohol) was the main product. Further, silver nanoparticles supported on hydrotalcite (AgNP@HT) converted cumene to cumene hydroperoxide at 80 °C with 80% selectivity. Both benchtop and oxygen-uptake experiments were used to probe the reaction mechanism and…
Enhanced plasmonic processes in amino-rich plasma polymer films for applications at the biointerface
2021
A new plasmonic biosensor was developed in a planar chip-based format by coupling the plasmonic properties of gold nanoparticles (Au NPs) with the mechanical and bioadhesive features of unconventional organic thin films deposited from plasma, namely primary amine-based plasma polymer films (PPFs). A self-assembled layer of spherical Au NPs, 12 nm in diameter, was electrostatically immobilized onto optically transparent silanised glass. In the next step, the Au NP layer was coated with an 18 nm polymeric thick PPF layerviathe simultaneous polymerization/deposition of a cyclopropylamine (CPA) precursor performed by radio frequency discharge, both in pulsed and in continuous wave modes. The CP…
Administration of a Synbiotic to Free-Living Elderly and Evaluation of Serum Cytokines. A Pilot Study
2010
Ten free-living elderly were administered with a synbiotic [fermented milk containing Lactobacillus rhamnosus Gorbach and Goldin (LGG)] and oligofructose as a prebiotic for one month. Serum cytokines were evaluated before (T(0)) and after (T(1)) synbiotic administration. At T(0), values of Interleukin (IL)-12, IL-6, IL-10, IL-1beta and Tumor Necrosis Factor (TNF)-alpha were lower than normal controls, with the exception of IL-8, thus confirming previous results on the impairment of both innate and adaptive responses in elderly. At T(1), the synbiotic was able to significantly increase, depressed values of IL-1, IL-6 and IL-8 with a trend to a modest increase for the restant cytokines. In co…
Custodie eucaristiche in Sicilia tra Tardo Gotico e Rinascimento
2021
Review of Eucharistic cases, aka monstrances, of architectural typology produced in Sicily between the 15th and 17th centuries. Analysis of the compositional and stylistic characteristics. Framing in the broader historical, artistic and cultural context of reference
1682 un'annata florida. Andrea Mamingari, Paolo Amato e un'inedita cassetta reliquiaria della Cattedrale di Palermo
2022
The study of an unprecedented reliquary box of the Cathedral of Palermo is an opportunity to reconstruct a happy productive context and expand the catalog of the works of the silversmith Andrea Mamingari
Immunochromatographic Assay for Quantitation of Milk Progesterone.
1996
We describe a rapid immunochromatographic method for the quantitation of progesterone in bovine milk. The method is based on a 'competitive' assay format using the monoclonal antibody to progesterone and a progesterone-protein conjugate labelled with colloidal gold particles. The monoclonal antibody to progesterone is immobilized as a narrow detection zone on a porous membrane. The sample is mixed with colloidal gold particles coated with progesterone-protein conjugate, and the mixture is allowed to migrate past the detection zone. Migration is facilitated by capillary forces. The amount of labelled progesterone-protein conjugate bound to the detection zone, as detected by photometric scann…
Electrochemical detection of uric acid and ascorbic acid using r-GO/NPs based sensors
2021
Abstract A sensitive and selective electrochemical sensor, based on reduced graphene oxide and gold nanoparticles obtained by simple co-electrodeposition, was developed for the detection of uric acid and ascorbic acid. Because of the electrochemical oxidation of both uric and ascorbic acid depending on the pH, the sensor performances were studied at different pH values. Excellent results were obtained for uric acid detection in a linear range from 10 to 500 µmol dm−3 with a sensitivity of 0.31 µA cm−2 µM−1. A limit of detection and quantification of 3.6 µM and 10.95 µmol dm−3, respectively, was calculated. Sensors showed good selectivity toward different interfering species present in the m…
Resorcinol Functionalized Gold Nanoparticles for Formaldehyde Colorimetric Detection
2019
[EN] Gold nanoparticles functionalized with resorcinol moieties have been prepared and used for detecting formaldehyde both in solution and gas phases. The detection mechanism is based on the color change of the probe upon the aggregation of the nanoparticles induced by the polymerization of the resorcinol moieties in the presence of formaldehyde. A limit of detection of 0.5 ppm in solution has been determined. The probe can be deployed for the detection of formaldehyde emissions from composite wood boards.
Characterization of Emergence of the Coulomb Blockade in a Pearl-Like DNA-AuNP Assembly
2023
Due to its superior self-assembly properties and vast functionalization pos-sibilities DNA has long been one of the most promising candidates forfabrication of nanoscale electrical components using molecular buildingblocks. There exist already many demonstrations on optical devices based onorganizing metallic nanoparticles (NP) via DNA self-assembly, but despite thepromises only few DNA based electrical devices or studies have been realizedso far. Here we study the gold NP conjugated and metallized DNA TX-tile-structure, which we recently showed to exhibit the room temperature Coulombblockade, the pre-requisition for a single electron transistor. The properties ofthe obtained Coulomb blocka…