Citrate-capped gold nanoparticles with different colours and diameters were prepared by the reduction of HAuCl4 using sodium citrate. With increasing the size of gold particles, the plasmon absorption peaks were shifted to longer wavelength and the intensity of resonance light scattering was enhanced. The resonance light scattering of gold nanoparticles in the range of 500–600nmwas quenched by ...

A simple and effective method is proposed to improve spectral sensitivity anddetection limit of long period gratings for refractive index or chemical sensing, where thegrating surface is modified by a monolayer of colloidal gold nanoparticles. Thetransmission spectra and optical properties of gold nanospheres vary with the differentrefractive index of the environment near the surface of gold na...

Different functions were imparted to ramie fibers through treatment with noble metal nanoparticles including silver and gold nanoparticles. The in situ synthesis of silver and gold nanoparticles was achieved by heating in the presence of ramie fibers in the corresponding solutions of precursors. The unique optical property of synthesized noble metal nanoparticles, i.e., localized surface plasmo...

In this study the influence of dicarboxy acetone (DCA), as an oxidation product of sodium citrate, was evaluated by ‘reversed Turkevich’ method in this study. Gold nanoparticles (GNPs) were synthesized systematically at various sodium citrate to HAuCl4 molar ratio and temperature. TheseThe GNPs were characterized by UV-vis spectroscopy, DLS and TEM techniques. The results showed that by reversi...

Hybrid materials of polyacrylamide networks and gold nanoparticles were prepared by directly heating an aqueous solution containing HAuCl(4), acrylamide, N,N'-methylenebis-acrylamide, and sodium sulfite (Na(2)SO(3)). Acrylamide, N,N'-methylenebis-acrylamide, and Na(2)SO(3) were used as monomers, crosslinking agent, and initiator, respectively. In the process of polyacrylamide network synthesis,...

The selective desorption/ionization of analytes using nanomaterials is investigated using metallic nanoparticles. By replacing the sodium citrate capping of gold nanoparticles with self-assembled monolayers, we are able to both enhance analyte ionization and selectively capture analytes. Capping gold nanoparticles with a monolayer of 4-mercaptobenzoic acid enhances analyte ionization while grea...

Well-defined gold nanobelts as well as unique gold nanocombs made of nanobelts were readily synthesized by the reduction of HAuCl4 with ascorbic acid in aqueous mixed solutions of the cationic surfactant cetyltrimethylammonium bromide (CTAB) and the anionic surfactant sodium dodecylsulfonate (SDSn). Single-crystalline gold nanobelts grown along the <110> and <211> directions were prepared in mi...

background: the particles in the range of 1-100 nm are called nanoparticles56t. gold nanoparticle is one of the most important metal nanoparticles with wide usage56t.objective: 56tthis study investigated the effects of gold nanoparticles on sperm parameters and chromatin structure in mice56t.materials and methods: 56tin this experimental study, 72 male bulb-c mice were divided into 9 groups inc...

Sodium borohydride or sodium tetrahydroborate is used as a reducing agent in many organic and inorganic reactions. Therefore, the determination of sodium borohydride present in the system is of great importance. Borohydride releases hydrogen under appropriated conditions in the presence of a suitable catalyst. Since the amount of hydrogen emitted is proportional to the amount of borohydride, th...

We compare the activity and relevant gold species of nanostructured gold–cerium oxide and gold–iron oxide catalysts for the CO oxidation by dioxygen and water. Well dispersed gold nanoparticles in reduced form provide the active sites for the CO oxidation reaction on both oxide supports. On the other hand, oxidized gold species, strongly bound on the support catalyze the water-gas shift reactio...