Ag-Au alloy nanoparticles with tunable shape and composition were prepared by a replacement reaction between Ag nanoparticles and chloroauric acid at one hundred and fifty degree celsius temperature under oilbath heating. The replacement reaction between silver nanostructures and chloroauric acid solution has recently been demonstrated as a versatile method for generating Au-Ag alloy nanostruct...

Titanium dioxide (TiO(2)) is one of the most widely studied and important materials for catalysis, photovoltaics, and surface science applications, but the ability to consistently control the relative exposure of higher surface energy facets during synthesis remains challenging. Here, we present the repeatable synthesis of highly reactive, rutile {001} or {101} facets on broad, sword-shaped TiO...

We show that naturally occurring chitinous nanostructures found on the wings of the Graphium butterfly can be used as substrates for surface-enhanced Raman scattering when coated with a thin film of gold or silver. The substrates were found to exhibit excellent biocompatibility and sensitivity, making them ideal for protein assaying. An assay using avidin/biotin binding showed that the substrat...

An environmentally friendly method using a cell-free extract (CFE) of Rhodopseudomonas capsulata is proposed to synthesize gold nanowires with a network structure. This procedure offers control over the shapes of gold nanoparticles with the change of HAuCl4 concentration. The CFE solutions were added with different concentrations of HAuCl4, resulting in the bioreduction of gold ions and biosynt...

Nanoscale localization of electromagnetic fields near metallic nanostructures underpins the fundamentals and applications of plasmonics. The unavoidable energy loss from plasmon decay, initially seen as a detriment, has now expanded the scope of plasmonic applications to exploit the generated hot carriers. However, quantitative understanding of the spatial localization of these hot carriers, ak...

Toroidal structures based on self-assembly of predesigned building blocks are well-established in the literature, but spontaneous self-organization to prepare such structures has not been reported to date. Here, organic-inorganic hybrid microtoroids synthesized by simultaneous coordination-driven assembly of amphiphilic molecules and hydrophilic polymers are reported. Mixing amphiphilic molecul...

Silver nanocrystals have been prepared by reacting silver nitrate with ascorbic acid in aqueous solution containing a low concentration of a commercial polynaphthalene sulfonate polymer (Daxad 19). Various crystalline morphologies have been obtained simply by tuning the reaction temperature. We have investigated the nanoparticle formation mechanism at three different temperatures by in situ and...

Here we report the wet-chemical synthesis of asymmetric one-dimensional (1D) silver "nanocarrot" structures that exhibit mixed twins and stacking fault domains along the <111> direction. Oriented attachment is the dominant mechanism for anisotropic growth. Multipolar plasmon resonances up to fourth order were measured by optical extinction spectroscopy and electron energy-loss spectroscopy (EEL...

Using picosecond excitation at 1064 nm, surface-enhanced hyper-Raman scattering (SEHRS) spectra of the nucleobases adenine, guanine, cytosine, thymine, and uracil with two different types of silver nanoparticles were obtained. Comparing the SEHRS spectra with SERS data from the identical samples excited at 532 nm and with known infrared spectra, the major bands in the spectra are assigned. Due ...

Plasmonic near-field coupling can induce the enhancement of photoresponsive processes by metal nanoparticles. Advances in nanostructured metal synthesis and theoretical modeling have kept surface plasmons in the spotlight. Previous efforts have resulted in significant intensity enhancement of organic dyes and quantum dots and increased absorption efficiency of optical materials used in solar ce...