Comparative Study of Catalytic Activity of Recyclable Au/FeO Microparticles for Reduction Of 2,4-Dinitrophenol and Anionic, Cationic Azo Dyes.

We synthesized Au/FeO microparticles. Initially, citrate-capped FeO micro-sized particles were synthesized by the co-precipitation method with an excess amount of trisodium citrate. Gold ions were reduced on the surface of citrate-capped FeO and grew as gold sub-microparticles with an average diameter of 210 nm on the surface.

Interactions between the antifungal drug myclobutanil and gold and silver nanoparticles in Penicillium digitatum investigated by surface-enhanced Raman scattering.

Surface-enhanced Raman scattering (SERS) of an antifungal reagent, myclobutanil (MCB), was performed on Au and Ag nanoparticles (NPs) to estimate the drug-release behaviors in fungal cells. A density functional theory (DFT) calculation was introduced to predict a favorable binding site of MCB to either the Ag or Au atom. Myclobutanil was presumed to bind more strongly to Au than to Ag in their most stable, optimized geometries of the N4 atom in its 1,2,4-triazole unit binding to the metal atom.

Gold nanorod-assembled PEGylated graphene-oxide nanocomposites for photothermal cancer therapy.

Gold nanorod-attached PEGylated graphene-oxide (AuNR-PEG-GO) nanocomposites were tested for a photothermal platform both in vitro and in vivo. Cytotoxicity of AuNR was reduced after encapsulation with PEG-GO along with the removal of cetyltrimethylammonium bromide (CTAB) from AuNR by HCl treatment. Cellular internalization of the CTAB-eliminated AuNR-PEG-GO nanocomposites was examined using dark-field microscopy (DFM), confocal Raman microscopy and transmission electron microscopy (TEM).

Temperature-dependent structural change of D-penicillamine-capped chiral gold nanoparticles investigated by infrared spectroscopy.

The structure and stability of D-penicillamine-capped gold nanoparticles (d-Pen Au NPs) were studied using spectroscopic tools. The synthesis of d-Pen Au NPs was examined using high-resolution transmission electron microscopy (HR-TEM), UV-vis absorption spectroscopy, and circular dichroism (CD). Temperature-dependent reversible structural changes of d-Pen Au NPs were observed using infrared spectroscopic tools.

Cytotoxicity of serum protein-adsorbed visible-light photocatalytic Ag/AgBr/TiO2 nanoparticles.

Photocytotoxicity of visible-light catalytic Ag/AgBr/TiO(2) nanoparticles (NPs) was examined both in vitro and in vivo. The Ag/AgBr/TiO(2) NPs were prepared by the deposition-precipitation method. Their crystalline structures, atomic compositions, and light absorption property were examined by X-ray diffraction (XRD) patterns, X-ray photoelectron (XPS) intensities, and ultraviolet-visible (UV-vis) diffuse reflectance spectroscopic tools.

Raman detection of localized transferrin-coated gold nanoparticles inside a single cell.

We investigated the cellular uptake behavior of non-fluorescent metal nanoparticles (NPs) by use of surface-enhanced Raman scattering (SERS) combined with dark-field microscopy (DFM). The uptake of Au NPs inside a single cell could also be identified by DFM first and then confirmed by z-depth-dependent SERS at micrometer resolution. Guided by DFM for the location of Au NPs, an intracellular distribution assay was possible using Raman dyes with unique vibrational marker bands in order to identify the three-dimensional location inside the single cell by obtaining specific spectral features.

Hydrogen bonding-induced color recovery of gold nanoparticles upon conjugation of amino acids.

Hydrogen bonding-induced redispersion of the aggregated Au nanoparticles upon N-hydroxysuccinimide ester bioconjugations may provide a simple and colorimetric tool as an optical sensor to detect a trace amount of amino acids as low as approximately 10(-6) M in an aqueous solution.

Infrared spectroscopy characterization of normal and lung cancer cells originated from epithelium.

The vibrational spectral differences of normal and lung cancer cells were studied for the development of effective cancer cell screening by means of attenuated total reflection infrared spectroscopy. The phosphate monoester symmetric stretching nu(s)(PO3(2-)) band intensity at ~970 cm(-1) and the phosphodiester symmetric stretching nu(s)(PO2(-)) band intensity at approximately 1,085 cm(-1) in nucleic acids and phospholipids appeared to be significantly strengthened in lung cancer cells with respect to the other vibrational bands compared to normal cells. This finding suggests that more extensive phosphorylation occur in cancer cells.

Adsorption changes of cyclohexyl isothiocyanate on gold surfaces.

The adsorption and structure of cyclohexyl isothiocyanate (CHIT) on gold surfaces has been investigated by surface-enhanced Raman scattering (SERS) and scanning tunneling microscopy (STM). Depending on the concentration, the spectral changes of the NCS stretching vibration on gold nanoparticles appeared to be more conspicuous than those of cyclohexyl ring modes. Both equatorial and axial chair conformers of CHIT were found to exist at low bulk concentrations near the monolayer coverage limit, whereas the equatorial chair conformer appeared to be dominant at high bulk concentrations.