the aim of this study is experimental assay of sensitivity and stability of a bimetallic silver/gold spr sensor chip. this chip utilizes the sensitivity of the silver and the stability of the gold. moreover, the silver layer (instead of usual cr or ti layer) was used as an adhesive intermediate layer between the gold layer and the glass substrate. the optimization of the gold/silver thickness u...

We demonstrate the utility of gold nanoparticles (AuNPs) as the basis of a stand-alone, inexpensive, and sensitive mercury monitor. Gold nanoparticles absorb visible light due to localized surface plasmon resonance (LSPR), and the absorbance changes when mercury combines with the gold nanoparticles. The sensitivity of the peak absorbance is proportional to the surface-area-to-volume ratio. We c...

In the Kretschmann configuration, the bulk metal is in the form of a thin film of uniform thickness, bounded on one side by a high–refractive–index dielectric material and on the other side by a low–refractive–index dielectric material. A plane wave is launched in the optically denser dielectric material towards the metal film, in order to excite a surface–plasmon wave at the interface of the m...

High quality nearly monodisperse colloidal WO3-x nanorods with an aspect ratio ∼18 were synthesized using the thermal decomposition technique. The effects of a capping agent and an activating agent on the nanorod aspect ratio have been studied. Excess carrier concentration due to large oxygen vacancy and smaller width of the nanorods compared to the Bohr exciton radius gives rise to an increase...

in this paper, scattering of a plane and monochromatic electromagnetic wave from a nano-wire is simulated using surface integral equations. first, integral equationsgoverning unknown fields on the surface is obtained based on stratton-cho surface integral equations. then, the interaction of the wave with a non-plasmonic as well as a palsmonic nano-wire is considered. it is shown that in scatter...

UNLABELLED Evenly separated crystalline CuIn0.8Ga0.2Se2 (CIGS) nanoparticles are deposited on ITO-glass substrate by pulsed laser deposition. Such CIGS layers are introduced between conjugated polymer layers and ITO-glass substrates for enhancing light absorbance of polymer solar cells. The P3HT:PCBM absorbance between 300 and 650 nm is enhanced obviously due to the introduction of CIGS nanopar...

The absorptive optical nonlinearity in nanoclusters of Au@hexanethiol and Au@dodecanethiol has been investigated. From the mass spectra, each cluster is estimated to contain about 140 atoms of gold. The optical absorption spectra of the clusters show a gradual increase in absorbance towards the UV region, over which an extremely weak surface plasmon resonance (SPR) is superposed. No plasmon ble...

A simplified synthesis of hollow gold nanoshells 20-50 nm in diameter via the well-established templated galvanic replacement reaction of silver for gold is presented. The surface plasmon resonance absorbance of the nanoshells is tuned using basic colloid chemistry to control the size of the silver templates. The gold nanoshells have an aqueous core and are varied in size and shell thickness de...

The hybridization kinetics for a series of designed 25mer probe-target pairs having varying degrees of secondary structure have been measured by UV absorbance and surface plasmon resonance (SPR) spectroscopy in solution and on the surface, respectively. Kinetic rate constants derived from the resultant data decrease with increasing probe and target secondary structure similarly in both solution...

Negative index metamaterials are demonstrated based on metal-dielectric nanocomposites prepared using a versatile bottom-up nanofabrication approach. The method involves the incorporation of vertically aligned metal nanowires such as Au and Ag inside dielectric aluminum oxide nanotemplates. Optical absorbance measurements show resonance peaks corresponding to the transverse and longitudinal sur...