PubMed Health⌕ Search

Biomedical subjects

Fangqiong Tang

Publications and source records attributed to Fangqiong Tang.

8 recordsLinked to original sources
PubMed2006

A simple solution route to single-crystalline Sb2O3 nanowires with rectangular cross sections.

We report a simple solution route to large-scale synthesis of uniform, single-crystalline, and well-faceted orthorhombic antimony trioxide (Sb(2)O(3)) nanowires with rectangular cross sections by direct air oxidation of bulk metal antimony (Sb) in a mixed solution made of ethylenediamine (EDA) and deionized water (DIW). The as-synthesized products were analyzed by range of methods, such as XRD, SEM, EDX, TEM, SAED, HRTEM, FTIR, Raman, UV-vis absorption, and photoluminescence (PL) spectra. The as-synthesized Sb(2)O(3) nanowires with rectangular cross sections are usually hundreds of micrometers in length, typically 80-100 nm in width, and 60-80 nm in thickness. The novel room temperature photoluminescence properties of Sb(2)O(3) nanowires with rectangular cross sections displayed a significant UV luminescence with a strong emission band at 374 nm, which was reported for the first time, indicating the as-synthesized products with an optical band gap E(g) = 3.3 eV. It is expected that as-synthesized Sb(2)O(3) nanowires would be a new member of functional materials and used in the manufacture of advanced nanodevices.

Antimony↗
PubMed2005

A new route to zinc-blende CdSe nanocrystals: mechanism and synthesis.

We report the possible mechanism of forming of CdSe nanocrystals in the high boiling point solvents with long alkane chains and a novel Non-TOP-Based route to zinc-blende CdSe nanocrystals. A new mechanism shows that there exits a redox reaction in the long alkane chain solvents: Se is reduced to H2Se gas; at the same time, the long alkane chains are oxidated to alkene chains; then, the Cd complex reacts with H2Se to form CdSe nanocrystals. Possible chemical reaction equations involved in the process of forming the CdSe nanocrystals have been discussed. The alkene chain and H2Se were detected respectively by a series of experiments to support the new mechanism. Under the guidance of this mechanism, we have developed a much cheaper and greener Non-TOP-Based route for the synthesis of a size series of high-quality zinc-blende (cubic) CdSe nanocrystals. Low-cost, green, and environmentally friendlier reagents are used, without use of expensive solvents such as trioctylphosphine (TOP) or tributylphosphine (TBP). The new route enables us to achieve high-quality CdSe nanocrystals with sharp ultraviolet and visible (UV-vis) absorption peaks, controllable size (2.0-5.0 nm), bright photoluminescence (PL), narrow PL full width of half-maximum (fwhm) (29-48 nm), and high PL quantum yield (up to 60%) without any size sorting.

Cadmium↗
PubMed2005

Shape-controlled synthesis of copper colloids with a simple chemical route.

The new electrical and optical properties of nanomaterials depend sensitively on both size and shape, which are of both fundamental and technological interest. This paper introduces a simple chemical method to produce copper particles, which has the ability to shape the particle without using any capping agent or template. In our synthetic procedure, the reactant concentration and temperature exerted a strong influence on the shape of the copper particles. At low reactant concentrations, the particles were cubic; at high reactant concentrations, obtained particles were spherical. The number of hollow particles greatly increased when the synthesis was performed at low temperature. We also synthesized a copper cubic ring at lower temperature, and it has been rarely reported. The absorption spectrum of hollow particles showed obvious red shifts, which suggests the possible assembly of novel optical materials.

Journal Article↗
PubMed2005

Preparation, structure, and magnetic properties of mesoporous magnetite hollow spheres.

Preparation of mesoporous Fe3O4 (magnetite) hollow spheres has been reported using hydrothermal synthesis and calcinations. The carboxyl-functionalized PS spheres were used as the templates coated by Fe3O4 particles and ethylene glycol (EG) as an organic structure directing agent. PS and EG were removed by calcinations method. The surface area after calcination at 500 degrees C is found to be 74 m(2) g(-1). The hollow spheres exhibited the weak ferromagnetism.

Journal Article↗
PubMed2004

Using silver nanoparticle to enhance current response of biosensor.

In this paper, we present a simple procedure to increase the sensitivity of a glucose biosensor. The feasibility of an amperometric glucose biosensor based on immobilization of glucose oxidase (GOx) in silver (Ag) sol was investigated for the first time. GOx was simply mixed with Ag nanoparticles and cross-linked with a polyvinyl butyral (PVB) medium by glutaraldehyde. Then a platinum electrode was coated with the mixed solution. The effects of the amount of the Ag particles used, with respect to the current response for enzyme electrodes, were studied. A set of experimental results indicate that the current response for the enzyme electrode containing hydrophobic Ag sol increased from 0.531 to 31.17 microA in the solution of 10 mmol/L beta-D glucose. The time reaching the steady-state current response reduced from 60 to 20s, three times less than those without Ag particles involved.

Biosensing Techniques↗
PubMed2004

Preparation, structure, and magnetic properties of polystyrene coated by Fe3O4 nanoparticles.

A novel method of fabricating core-shell structure particles, comprising nearly monodisperse polystyrene (PS) spheres as cores and Fe3O4 as shells, is submitted. In this research, the magnetite (Fe3O4) shell was prepared by seeded growth from the reaction of FeCl2 with diethylene glycol (DEG) in aqueous solutions. The thickness of the shell were controlled in the range of 0-60 nm by using slow injection. The composition and the structure of the shell were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TG), and vibrating-sample magnetometry (VSM). It is found that there are some differences between the magnetic composite spheres shelled with Fe3O4 and pure Fe3O4 particles, such as the size of the magnetites and the ferromagnetic property. Furthermore, the spheres exhibited the superparamagnetic characterization when the thickness of the Fe3O4 shell was less than 15 nm.

Journal Article↗
PubMedDate not supplied

Controlled drug delivery system based on magnetic hollow spheres/polyelectrolyte multilayer core-shell structure.

A novel controlled drug delivery system was fabricated by coating chitosan/PAA multilayer onto magnetic hollow spheres via a "Layer-by-Layer" (LBL) assembly approach. Cefradine was used as a model drug to evaluate the drug release characteristics of this core-shell hollow structure and the results show that it exhibits a sustained release of the drug and the release rate can be regulated by the pH environment of release medium. It is believed that this core-shell hollow structure, which combines the advantage of controlled delivery as well as magnetic targeting, has commendable potential in drug delivery therapeutics.

Acrylic Resins↗