Biomedical subjects

Daniela Zanchet

Publications and source records attributed to Daniela Zanchet.

4 recordsLinked to original sources

PubMed2006

A simple two-phase route to silver nanoparticles/polyaniline structures.

Novel silver nanoparticles/polyaniline composites were obtained through a two-phase water/toluene interfacial reaction. We show that by rigorously controlling the reaction time, different structures of the nanocomposites can be obtained, such as a thin sheet of polyaniline around the silver nanoparticles or a polymer mass with nanoparticles homogeneously embedded within it. Samples were characterized by FT-IR, UV-vis-NIR and Raman spectroscopy, X-ray diffraction, cyclic voltammetry, TEM, and HRTEM. Conductivity and current-voltage characteristics of the nanocomposites were measured, and the results indicate that different properties result from the different structures in which the nanocomposites were formed.

Journal Article↗

PubMed2005

Influence of synthetic parameters on the size, structure, and stability of dodecanethiol-stabilized silver nanoparticles.

Metal nanoparticles (NP) are very attractive because of their size- and shape-dependent properties. A widely used preparation of ligand-stabilized metal NP is the two-phase liquid-liquid method using dodecanethiol (DT) as ligand. This work presents various procedures to synthesize dodecanethiol-capped silver NPs, all of them based on a two-phase liquid-liquid method. Small alterations in the synthetic parameters lead to dramatic modifications in the nanoparticles' average size, size distribution width, stability, and structure, as well as in their ability to self-assemble.

Chemical Phenomena↗

PubMed2002

Synthesis of hcp-Co Nanodisks.

hcp Co disk-shaped nanocrystals were obtained by rapid decomposition of cobalt carbonyl in the presence of linear amines. Other surfactants, in addition to the amines, like phosphine oxides and oleic acid were used to improve size dispersion, shape control, and nanocrystal stability. Co disks are ferromagnetic in character and they spontaneously self-assemble into long ribbons. X-ray and electron diffraction, electron microscopy, and SQUID magnetometry have been employed to characterize this material.

Amines↗

PubMed2002

Sorting fluorescent nanocrystals with DNA.

Semiconductor nanocrystals with narrow and tunable fluorescence are covalently linked to oligonucleotides. These biocompounds retain the properties of both nanocrystals and DNA. Therefore, different sequences of DNA can be coded with nanocrystals and still preserve their ability to hybridize to their complements. We report the case where four different sequences of DNA are linked to four nanocrystal samples having different colors of emission in the range of 530-640 nm. When the DNA-nanocrystal conjugates are mixed together, it is possible to sort each type of nanoparticle by using hybridization on a defined micrometer-size surface containing the complementary oligonucleotide. Detection of sorting requires only a single excitation source and an epifluorescence microscope. The possibility of directing fluorescent nanocrystals toward specific biological targets and detecting them, combined with their superior photostability compared to organic dyes, opens the way to improved biolabeling experiments, such as gene mapping on a nanometer scale or multicolor microarray analysis.

DNA↗