Search results for " Silica nanoparticles"

showing 7 items of 17 documents

Finely Tuned Temperature-Controlled Cargo Release Using Paraffin-Capped Mesoporous Silica Nanoparticles

2011

[EN] Trapped: Mesoporous silica nanoparticles were loaded with a fluorescent guest and functionalized with octadecyltrimethoxysilane. The alkyl chains interact with paraffins, which build a hydrophobic layer around the particle (see picture). Upon melting of the paraffin, the guest molecule is released, as demonstrated in cells for the guest doxorubicin. The release temperature can be tuned by choosing an appropriate paraffin. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Models MolecularINGENIERIA DE LA CONSTRUCCIONGuest moleculesParaffinsParaffin waxesNanoparticlemesoporous materialsMCM-41Phenazine derivativeFunctionalizedCell survivalNanoparticleQUIMICA ORGANICAChemical structureX-Ray DiffractionSafranin tSilicon dioxideControlled releaseAlkyl chainDrug CarriersMicroscopy ConfocalMolecular StructureOctadecyltrimethoxysilaneSurface propertyTemperatureSilicaGeneral MedicineChemistryAntineoplastic agentParaffinHeLa cellPorosityHumanMaterials scienceDrug carrierX ray diffractionSurface PropertiesMesoporous silica nanoparticlesNanotechnologyAntineoplastic AgentsMesoporousCatalysisDrug interactionsArticleMicroscopy Electron TransmissionHumansCell survivalDrug effectDelayed release formulationHydrophobic layersQUIMICA INORGANICAGeneral ChemistryMesoporous silicaMolecular gatesMesoporous materialsMcm 41Confocal microscopyDrug effectSolubilityDoxorubicinDelayed-Action Preparationsdrug deliveryDrug deliveryNanoparticlesPhenazinesnanoparticlesMesoporous materialcontrolled releasemolecular gatesTransmission electron microscopyHeLa CellsAngewandte Chemie
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Nanosensor for Sensitive Detection of the New Psychedelic Drug 25I-NBOMe.

2020

[EN] This work reports the synthesis, characterization, and sensing behavior of a hybrid nanodevice for the detection of the potent abuse drug 25I-NBOMe. The system is based on mesoporous silica nanoparticles, loaded with a fluorescent dye, functionalized with a serotonin derivative and capped with the 5-HT2A receptor antibody. In the presence of 25I-NBOMe the capping antibody is displaced, leading to pore opening and rhodamine B release. This delivery was ascribed to 5-HT2A receptor antibody detachment from the surface due to its stronger coordination with 25I-NBOMe present in the solution. The prepared nanodevice allowed the sensitive (limit of detection of 0.6 mm) and selective recogniti…

SerotoninMesoporous silica nanoparticles25I-NBOMehallucinogenic drugsMescalinesensorsCatalysischemistry.chemical_compoundAgonist 5-HT2A serotonin receptorQUIMICA ORGANICAQUIMICA ANALITICAmedicineRhodamine BHumansmesoporous silica nanoparticlesNanodeviceLysergic acid diethylamideDetection limitSensorsQUIMICA INORGANICAOrganic ChemistryMDMAGeneral ChemistryMesoporous silicaHallucinogenic drugs25I-NBOMeCombinatorial chemistrychemistryDimethoxyphenylethylamine25I-NBOMe agonist 5-HT2A serotonin receptor hallucinogenic drugs mesoporous silica nanoparticles sensorsHallucinogensagonist 5-HT2A serotonin receptormedicine.drug
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Self-limiting and complete oxidation of silicon nanostructures produced by laser ablation in water

2016

Oxidized Silicon nanomaterials produced by 1064 nm pulsed laser ablation in deionized water are investigated. High-resolution transmission electron microscopy coupled with energy dispersive X-ray spectroscopy allows to characterize the structural and chemical properties at a sub-nanometric scale. This analysis clarifies that laser ablation induces both self-limiting and complete oxidation processes which produce polycrystalline Si surrounded by a layer of SiO2 and amorphous fully oxidized SiO2, respectively. These nanostructures exhibit a composite luminescence spectrum which is investigated by time-resolved spectroscopy with a tunable laser excitation. The origin of the observed luminescen…

Silicon nanocrystal Silica nanoparticles laser ablation Time resolved phtoluminescence High resolution transmission electron microscopy Silicon Oxidation Quantum Confinment DefectsMaterials scienceLaser ablationPhotoluminescenceSiliconSettore FIS/01 - Fisica SperimentaleAnalytical chemistryGeneral Physics and Astronomychemistry.chemical_element02 engineering and technology010402 general chemistry021001 nanoscience & nanotechnology01 natural sciences0104 chemical sciencesAmorphous solidNanomaterialschemistry0210 nano-technologyLuminescenceSpectroscopyTunable laser
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Luminescence from nearly isolated surface defects in silica nanoparticles

2015

A structured emission/excitation pattern, proper of isolated defects, arises in a vacuum from silica nanoparticles. The luminescence, centered around 3.0-3.5 eV, is characterised by a vibronic progression due to the phonon coupling with two localised modes of frequency  ∼1370 cm(-1) and  ∼360 cm(-1), and decays in about 300 ns at 10 K. On increasing the temperature, the intensity and the lifetime decrease due to the activation of a non-radiative rate from the excited state. Concurrently, the temperature dependence of the lineshape evidences the low coupling with non-localised modes of the matrix (Huang-Rhys factor S ~ 0.2) and the poor influence of the inhomogeneous broadening. These findin…

Surface (mathematics)Field (physics)ChemistryPhononNanotechnologyCondensed Matter PhysicsMolecular physicsCrystallographic defectAmorphous solidExcited statetime-resolved luminescence silica nanoparticles point defects vibronic transitions electron–phonon couplingGeneral Materials ScienceLuminescenceIntensity (heat transfer)Journal of Physics: Condensed Matter
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Rapid and eco-friendly synthesis of graphene oxide-silica nanohybrids

2014

The increasing interest in Graphene oxide (GO) is due to many issues: the presence of both sp2-conjugated atoms and oxygen-containing functional groups provides a strong hydrophilicity and the possibility to further functionalize it with other molecules (i.e. π-π interactions covalent attachment etc.) [1]. Furthermore since the GO is biocompatible and noncytotoxic many studies have been recently focused on the development of GO-based nanodevices for bioimaging DNA detection drug delivery. Due to their low cytotoxicity and large internal surface area silica nanoparticles have been taken into account as promising material for biolabeling and drug loading/delivery. Particular consideration has recently been demonstrated for GO-silica composites because of the potentialities for electrical applications their chemical inertia and stability toward ions exposure. The possibility to combine the extraordinary properties of GO and silica offers several advantages for the realization of nanoprobes for biological applications and of biosensor [12]. The strategy for the fabrication of GO-nanosilica nanohybrids can be schematized as follows: (i) synthesis of GO by oxidizing graphite powder with the method described by Marcano et al. [3] (ii) Preparation of oxygen-loaded silica nanoparticles by thermal treatments in controlled atmosphere in order to induce high NIR emission at 1272 nm from high purity silica nanoparticles. (iii) preparation of GrO-silica nanohybrid films via rapid solvent casting in water. The nanohybrids were tested by XPS FTIR Raman analysis UV photoluminescence analysis TGA Zeta potential measurements electrical tests AFM and SEM. Several nanohybrids were prepared by combining two different typologies of GO and two different samples of silica.
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MODIFICA SUPERFICIALE DI FILM DI POLY(ETILENE-co-ACIDO ACRILICO) CON NANOPARTICELLE DI SILICE ATTIVATA

2009

chemical surface modification hybrid materialsgrafting from grafting to silica nanoparticles
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Protein recovery as a resource from waste specifically via membrane technology : from waste to wonder

2021

Economic growth and the rapid increase in the world population has led to a greater need for natural resources, which in turn, has put pressure on said resources along with the environment. Water, food, and energy, among other resources, pose a huge challenge. Numerous essential resources, including organic substances and valuable nutrients, can be found in wastewater, and these could be recovered with efficient technologies. Protein recovery from waste streams can provide an alternative resource that could be utilized as animal feed. Membrane separation, adsorption, and microbe-assisted protein recovery have been proposed as technologies that could be used for the aforementioned protein re…

potato processing wastemembrane foulingmicroalgaejätevesikalvotekniikka (erotusmenetelmät)talteenottopurple phototrophic bacteriaelintarviketeollisuusbiomassa (teollisuus)mikrobitproteiinitmesoporous silica nanoparticlesadsorptioalfalfa processing wastedairy waste proteinwastewaters
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