Search results for " NANOPARTICLES"
showing 10 items of 794 documents
Antibacterial Properties of Nanoparticles in Dental Restorative Materials. A Systematic Review and Meta-Analysis
2020
Background and Objectives: Nanotechnology has become a significant area of research focused mainly on increasing the antibacterial and mechanical properties of dental materials. The aim of the present systematic review and meta-analysis was to examine and quantitatively analyze the current evidence for the addition of different nanoparticles into dental restorative materials, to determine whether their incorporation increases the antibacterial/antimicrobial properties of the materials. Materials and Methods: A literature search was performed in the Pubmed, Scopus, and Embase databases, up to December 2018, following PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) …
Stir bar sorptive-dispersive microextraction mediated by magnetic nanoparticles-nylon 6 composite for the extraction of hydrophilic organic compounds…
2016
A new and sensitive analytical method based on the recently developed approach termed stir bar-sorptive dispersive microextraction (SBSDME) using a magnetic CoFe2O4@SiO2-nylon 6 composite as sorbent material is presented for the extraction of hydrophilic organic compounds. The simultaneous determination of four hydrophilic UV filters in environmental water samples has been chosen as a model analytical application due to the increasing awareness regarding the occurrence of sunscreen residuals in natural waters. The developed SBSDME approach combines the principles and benefits of stir bar sorptive extraction (SBSE) and dispersive solid phase extraction (DSPE) but allows for lower extraction …
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.
Use of gold nanoparticle-coated sorbent materials for the selective preconcentration of sulfonylurea herbicides in water samples and determination by…
2012
Abstract Two new gold nanoparticle (NP) coated materials (silica supported on gold NP with and without ionic liquid) were synthesized for solid phase extraction of sulfonylurea herbicides (SUHs), such as bensulfuron-methyl (BSM), metsulfuron-methyl (MSM), pyrazosulfuron-methyl (PSM), thifensulfuron-methyl (TFM) and triasulfuron (TS), from water samples, followed by capillary liquid chromatography coupled to diode array detection (CLC–DAD). Several factors influencing the preconcentration efficiency of SUHs and its subsequent determination, such as pH of the sample, eluent and reusability of sorbents, have been investigated. Under the optimum conditions, the developed method allowed the dete…
Polydopamine-coated magnetic nanoparticles for the determination of nitro musks in environmental water samples by stir bar sorptive-dispersive microe…
2021
Magnetic-based microextraction approaches have gained popularity in recent years due to the magnetic properties of the extraction phases allowing to handle them easier and more efficiently. This work describes a magnetic-based analytical method for the determination of the family of nitro musks in environmental water samples. These compounds have been of great concern due to their environmental impacts and potential health effects. The method is based on stir bar sorptive-dispersive microextraction (SBSDME) as extraction approach, prior to thermal desorption coupled to gas chromatography-mass spectrometry analysis (TD-GC-MS). For this purpose, polydopamine-coated cobalt ferrite magnetic nan…
Development of stir bar sorptive-dispersive microextraction mediated by magnetic nanoparticles and its analytical application to the determination of…
2014
A novel microextraction technique combining the principles of stir bar sorptive extraction (SBSE) and dispersive micro-solid phase extraction (DμSPE) is presented. The main feature of the method is the use of a neodymium-core stirring bar physically coated with a hydrophobic magnetic nanosorbent. Depending on stirring speed, the magnetic sorbent either acts as a coating material to the stir bar, thus affording extraction alike SBSE, or as a dispersed nanosorbent medium for the collection and extraction of the target analytes, in close analogy to DμSPE. Once the stirring process is finished, the strong magnetic field of the stir bar prevails again and rapidly retrieves the dispersed MNPs. Al…
Application of stable isotopes and AF4/ICP-SFMS for simultaneous tracing and quantification of iron oxide nanoparticles in a sediment–slurry matrix
2016
One major challenge in nanomaterial analysis, especially in complex environmental matrices, is the unambiguous differentiation between natural and engineered nanomaterials (ENMs). Particularly with regard to the investigation of ENM's/engineered nanoparticle's (ENPs) fate, analytical methods are needed allowing for tracing and sensitive quantification. Several ENPs are metal-based and contain elements being omnipresent in environmental matrices (e.g., Al, Ti, Zn, Fe and non-metal Si) – hence, high background levels of these elements are expected, compromising sensitive detection. In this work we developed successfully a combined approach of stable isotope labeling (tracing) and reverse post…
Multifunctional two-photon active silica-coated Au@MnO Janus particles for selective dual functionalization and imaging.
2014
Monodisperse multifunctional and nontoxic Au@MnO Janus particles with different sizes and morphologies were prepared by a seed-mediated nucleation and growth technique with precise control over domain sizes, surface functionalization, and dye labeling. The metal oxide domain could be coated selectively with a thin silica layer, leaving the metal domain untouched. In particular, size and morphology of the individual (metal and metal oxide) domains could be controlled by adjustment of the synthetic parameters. The SiO2 coating of the oxide domain allows biomolecule conjugation (e.g., antibodies, proteins) in a single step for converting the photoluminescent and superparamagnetic Janus nanopar…
Fabrication of silver nanoparticles by a diethylene triamine-hyaluronic acid derivative and use as antibacterial coating
2022
In this work a synthetic protocol for the functionalization of hyaluronic acid with diethylenetriamine (DETA) was standardized. HA-DETA derivatives were characterized by NMR and proton carbon correlation analysis HSQC and HMBC to confirm chemical structure. A selected derivative was used to set up a green fabrication procedure for HA-DETA capped silver nanoparticles with the aim to achieve a polymeric based coating with potential application in the treatment of medical devices associated infections. Data from UV-visible spectroscopy, electron scanning and transmission microscope (STEM), photoelectric spectroscopy (XPS) and rheological characterization were combined to characterize the HA-DE…
Apoferritin-encapsulated Ni and Co superparamagnetic nanoparticles
2006
Ni and Co nanoparticles (average diameters 3 and 3.5 nm) have been prepared within the apoferritin cavity. The protein shell prevents bulk aggregation of the metal particles, rendering them water soluble. X-Ray diffraction, transmission electronic microscopy and magnetization measurements have been used for characterizing the nanoparticles. The magnetic study of both nanoparticles confirmed the expected superparamagnetic behavior.