Search results for "Silica nanoparticle"
showing 10 items of 59 documents
Fluorogenic detection of Tetryl and TNT explosives using nanoscopic-capped mesoporous hybrid materials
2013
[EN] A hybrid capped mesoporous material, which was selectively opened in the presence of Tetryl and TNT, has been synthesised and used for the fluorogenic recognition of these nitroaromatic explosives.
Vibronic structures in the visible luminescence of silica nanoparticles
2014
Time resolved photoluminescence investigation in air and in vacuum atmosphere of the visible luminescence related to silica surface defects is here reported. Two contributions can be singled out: one, observed both in air and in vacuum, is the well-known blue band, peaked around 2.8 eV decaying in ∼5 ns; the other, only observed in vacuum, is a structured emission in the violet range characterized by two vibronic progressions spaced 1370 cm−1 and 360 cm−1 decaying in ∼100 ns. In contrast with previous attribution, the well distinguishable spectroscopic properties together with the observation of the effects induced by the interaction with nitrogen allow to state that the emission bands orig…
Formulation of Mesoporous Silica Nanoparticles for Controlled Release of Antimicrobials for Stone Preventive Conservation
2020
The biotic deterioration of artifacts of archaeological and artistic interest mostly relies on the action of microorganisms capable of thriving under the most disparate environmental conditions. Thus, to attenuate biodeterioration phenomena, biocides can be used by the restorers to prevent or slow down the microbial growth. However, several factors such as biocide half-life, its wash-out because of environmental conditions, and its limited time of action make necessary its application repeatedly, leading to negative economic implications. Sound and successful treatments are represented by controlled release systems (CRSs) based on porous materials. Here, we report on the design and developm…
New biocides based on imidazolinium-functionalised hybrid mesoporous silica nanoparticles
2022
Here, we report the development of a new biocide based on hybrid mesoporous silica nanoparticles (MSN). The MSN was synthesized by condensation method in emulsion followed by grafting with two different silylated ionic liquid moieties, namely butyl imidazolinium bromide and imidazolinium propansulfonate betaine. Features of nanoparticles were characterized by Thermogravimetry, Infrared and ss-NMR Spectroscopy, and Transmission Electron Microscopy. The antibacterial properties were tested against a Gram-positive bacterial strain previously isolated from artefacts of interest in the field of Cultural Heritage. Interestingly, the hybrid material presents an antibacterial activity higher than i…
Combination of silica nanoparticles with hydroxyapatite reinforces poly (l-lactide acid) scaffolds without loss of bioactivity
2013
Composite scaffolds of poly(l-lactide acid) and hydroxyapatite are of great interest in bone tissue engineering, but their mechanical properties are typically inferior to scaffolds of pure poly(l-lactide acid) due to agglomeration of the particles and weak interfacial component interaction. Fabrication strategies like double sonication of hydroxyapatite or increasing the amount of this inorganic filler do not effectively enhance the mechanical performance. In this study, poly(l-lactide acid) composites combining two types of fillers, mesoporous silica (SiO2) nanoparticles and hydroxyapatite, were developed to reinforce the poly(l-lactide acid) scaffold without any loss of bioactivity. A 5%…
Mesoporous Silica Nanoparticles in Chemical Detection: From Small Species to Large Bio-Molecules
2021
A recompilation of applications of mesoporous silica nanoparticles in sensing from the last five years is presented. Its high potential, especially as hybrid materials combined with organic or bio-molecules, is shown. Adding to the multiplying effect of loading high amounts of the transducer into the pores, the selectivity attained by the interaction of the analyte with the layer decorating the material is described. Examples of the different methodologies are presented.
Thermally Induced Structural Modification of Silica Nanoparticles Investigated by Raman and Infrared Absorption Spectroscopies
2010
We report an experimental investigation by Raman and infrared (IR) absorption spectroscopies on the structural modifications induced by isochronal thermal treatments on amorphous SiO2 nanoparticles (fumed silica). In particular, three different commercial types of this material, characterized by particle mean diameters of 7, 14, and 40 nm, were subjected to thermal treatments from 100 up to 1000 °C. We found that some properties of fumed silica, such as the SiOSi mean bond angle, ring size distribution, and surface adsorbed water content, are drastically different from those of common bulk silica materials and intimately related to the particles' dimension. The SiOSi mean bond angle, probed…
Selective, Highly Sensitive, and Rapid Detection of Genomic DNA by Using Gated Materials:MycoplasmaDetection
2013
The coupling of gated-indicator delivery with highly specific biochemical recognition is an innovative strategy for the detection of DNA sequences, able to compete with classical methods which need PCR amplification, in important areas such as point-of-care diagnostics or detection of specific biological contaminations with pathogens. Such comparatively simple and cheap yet highly selective and sensitive assays hold promise for use in less-developed areas of the world.
Flotillin-involved uptake of silica nanoparticles and responses of an alveolar-capillary barrier in vitro
2013
AbstractDrug and gene delivery via nanoparticles across biological barriers such as the alveolar-capillary barrier of the lung constitutes an interesting and increasingly relevant field in nanomedicine. Nevertheless, potential hazardous effects of nanoparticles (NPs) as well as their cellular and systemic fate should be thoroughly examined. Hence, this study was designed to evaluate the effects of amorphous silica NPs (Sicastar) and (poly)organosiloxane NPs (AmOrSil) on the viability and the inflammatory response as well as on the cellular uptake mechanisms and fate in cells of the alveolar barrier. For this purpose, the alveolar epithelial cell line (NCI H441) and microvascular endothelial…
Selective and Sensitive Chromofluorogenic Detection of the Sulfite Anion in Water Using Hydrophobic Hybrid Organic-Inorganic Silica Nanoparticles
2013
[EN] In water and wine: Chromofluorogenic detection of the sulfite anion in pure water was accomplished by using a new hybrid organic-inorganic material that contained a probe entrapped in hydrophobic biomimetic cavities. This material was used for the detection of sulfite in red wine. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.