Search results for "nanoparticle"

Ferricytochrome c encapsulated in silica nanoparticles: structural stability and functional properties.

2004

Using a modified sol-gel technique, we have succeeded in encapsulating ferric cytochrome c in silica nanoparticles obtained from hydrolysis and polycondensation of tetramethylorthosilicate. Particles dimensions have been determined with dynamic light scattering; this technique yields an hydrodynamic radius of about 100 nm, each nanoparticle containing about 10(2)-10(3) proteins. If stored in the cold at low ionic strength, nanoparticles are stable for more than one week, even if a slow radius increase with time is observed. CD measurements show that encapsulated proteins exhibit substantially increased stability against guanidinium hydrochloride induced denaturation. Reduction kinetics of e…

Exploring the binding of Pt drugs to gold nanoparticles for controlled passive release of cisplatin.

2011

Bone-Targeted Cisplatin-Complexed Poly(γ-benzyl-L-glutamate)-Poly(glutamic acid) Block Polymer Nanoparticles: An Electrochemical Approach

2015

The voltammetric response of different osteotropic multifunctional nanoparticles based on cisplatin-complexed poly(γ-benzyl-L-glutamate)–poly(glutamic acid) block polymer (CDDP-PBLG-b-PGlu) copolymer, with or without poly(γ-benzyl-L-glutamate)–poly(ethylene glycol) block polymer (PBLG-b-PEG), and having bone-targeting properties is studied at biologically relevant pH. Significant differences in the cisplatin-centered voltammetric signals allow monitoring of the association of cisplatin to nanoparticles as well as release kinetics from them, in agreement with atomic absorption spectroscopy data. Electrochemical studies reveal that the cisplatin association is significant only if the proporti…

Multifunctional halloysite and hectorite catalysts for effective transformation of biomass to biodiesel

2023

Halloysite surface was modified with tetrabutylammonium iodide, and then the obtained nanomaterial was used as support for ZnO nanoparticles. After characterization, the nanomaterial was used as a catalyst for fatty acid methyl esters (FAMEs) production. The recyclability of the nanomaterial was also investigated, and the optimization of reaction conditions by the design of experiments approach was performed as well. In addition, the synthesized nanomaterial was tested as a catalyst for FAME production from a series of waste lipids affording biodiesel in moderate to good yields (35–95%), depending on the matrix. To fully exploit the feasibility of clay minerals as catalysts in biodiesel for…

Cloud point–dispersive μ-solid phase extraction of hydrophobic organic compounds onto highly hydrophobic core–shell Fe 2 O 3 @C magnetic nanoparticles

2012

Abstract A novel two-step extraction technique combining cloud point extraction (CPE) with dispersive micro-solid phase extraction (D-μ-SPE) is presented in this work for the first time. The method involves initial extraction of the target analytes by CPE in the micelles of a non-ionic surfactant medium; then highly hydrophobic polysiloxane-coated core–shell Fe 2 O 3 @C magnetic nanoparticles (MNPs) are used to retrieve the micellar phase. In that manner, the micellar phase containing the analytes is the target of the D-μ-SPE step rather than the analytes directly. MNPs are then collected by the application of an adscititious magnetic field overcoming the need for specific steps associated …

Impact of Ag and Co engineered nanoparticles on soil microbial community structure in a soil perturbed by Lumbricus rubellus

2014

Knowledge on the impact of engineered nanomaterials (ENMs) on both human and environment health is scarce. Several studies sustain that soil is the environmental compartment designed to be the major recipient of engineered nanoparticles (NPs). With the aim of investigating the impact of commercially relevant NPs on soil functioning, we compared the effect of Ag and Co NPs, as well as cobalt and silver ions, on soil microbial community in the presence of Lumbricus rubellus. Earthworms specimens were placed in a rich‐C soil and fed with horse manure spiked with Ag‐NPs, Co‐NPs, Ag+ and Co2+ for a total amount of 10 mg of single pollutant kg‐1 soil. At the end of acute exposure (4 weeks) to pol…

Photocatalytic coalescence of functionalized gold nanoparticles.

2009

A novel strategy for the synthesis of chromophore-functionalized AuNPs with a narrow size distribution is reported. It consists of increasing the size of preprepared NPs by means of a fast (second scale) and clean (light and an organic photocatalyst) method. The results agree with thiolate ligand liberation from the NP surface promoted by photogenerated radicals. This lets gold cores come together and finally coalesce.

Polyorganosiloxane nanoparticles as optical tracers

2007

Polyorganosiloxane microgels have been synthesized by polycondensation in a microemulsion of trimethoxysilanes. Highly crosslinked rather monodisperse particles of radius about 10 nm are obtained.

Chemical Routes Toward Multicompartment Colloids

2012

The search for mimicking natural living and non-living systems with synthetic products leads to the fabrication of advanced colloidal morphologies with hierarchical micro- and nanostructures. Different chemical routes toward the synthesis of colloids with complex morphologies are presented and a tentative analogy between these routes and the four basic arithmetic operations is proposed.

Overview of the Evolution of Silica-Based Chromo-Fluorogenic Nanosensors

2019

[EN] This review includes examples of silica-based, chromo-fluorogenic nanosensors with the aim of illustrating the evolution of the discipline in recent decades through relevant research developed in our group. Examples have been grouped according to the sensing strategies. A clear evolution from simply functionalized materials to new protocols involving molecular gates and the use of highly selective biomolecules such as antibodies and oligonucleotides is reported. Some final examples related to the evolution of chromogenic arrays and the possible use of nanoparticles to communicate with other nanoparticles or cells are also included. A total of 64 articles have been summarized, highlight…