Monolayer-protected Au, Ag, and Au:Ag alloy nanoclusters have been synthesized using octanethiol and octadecanethiol as capping agents. The particle-size distribution is narrow with an average core size of 3–4 nm. Optical nonlinearity induced by 35 ps pulses at 532 nm has been investigated in these samples using the Z-scan technique. It is found that in general, they behave either as saturable ...

Pigmentation of the oral mucosa is relatively common and has a wide variety of etiologies. Although most pigmented lesions of the oral mucosa are associated with deposition of melanin and accidental displacement of a dental alloy, accurate differential diagnosis of a pigmented lesion is important, especially in the case of malignant melanoma. We report two cases of oral mucosal pigmentation ass...

Nanotechnology has dynamically developed as an important field of modern research with potential effects in electronic and medicine (Glomm 2005, Chan 2006, Boisselier and Astruc 2009). Nanotechnology can be defined as a research for the design, synthesis, and manipulation of structure of particles with dimension smaller than 100nm. A new branch of nanotechnology is nanobiotechnology. Nanobiotec...

Fathoming the principles underpinning the structures of monolayer-coated molecular metal nanoparticles remains an enduring challenge. Notwithstanding recent x-ray determinations, coveted veritable de novo structural predictions are scarce. Building on recent syntheses and de novo structure predictions of M3Au x Ag17-x (TBBT)12, where M is a countercation, x = 0 or 1, and TBBT is 4-tert-butylben...

A microfluidic setup which enables on-line monitoring of residues of malachite green (MG) using surface-enhanced Raman scattering (SERS) is reported. The SERS active substrate was prepared via laser induced synthesis of silver or gold nanoparticles spot on the bottom of a 200 μm inner dimension glass capillary, by focusing the laser beam during a continuous flow of a mixture of silver nitrate o...

Gold-core/silver-shell nanoparticles featuring core diameters of 13 or 25 nm were prepared in aqueous solution. Silver-coated gold nanoparticles have two distinct plasmon absorption bands whose relative intensities depend on the shell thickness – features that are captured well by classical Mie theory. The core/shell spectra are not simply linear combinations of the pure-component spectra. Theo...

The aim of this one-year project is to develop synthetic methods to form well-defined colloidal assemblies of metal nanoparticles and to understand their unique optical properties focusing on magnetic resonance scattering and surface enhanced Raman scattering (SERS). Our synthetic approach is based on the templated surfactant-assisted seed growth method, where polymer particles decorated with s...

Nanotechnology is new form of technology which has produced a great development in variousfields. Nanoparticles are of the great scientific interest as they are effectively a bridge between bulk material and atomic & molecular structures. Nanoparticles are the particle that have size 1 to 100 nm and possess due to large surface area to volume ratio & smaller size. Different types of nanom...

We demonstrate that the fluorescence rate from a single molecule with near-unity quantum yield can be enhanced by a factor of ≈10 by use of a single laser-irradiated noble metal nanoparticle. The increased fluorescence rate is primarily the result of the local field enhancement. However, at particle–molecule distances shorter than 2 nm, nonradiative decay of the excited molecule due to energy t...

Gold nanoparticles are one of the most used nanomaterials. They are usually synthesized by the reduction of gold(III) chloride. However, the presence of halide ions in the reaction mixture is not always welcome. In some cases, these ions have detrimental influence on the morphology and structure of resulting nanoparticles. Here, we present a simple and halogen-free procedure to prepare gold nan...