Straightforward phase-transfer route to colloidal iron oxide nanoparticles for protein immobilization

© The Royal Society of Chemistry 2015. We report for the first time the effective transfer of hydrophobic oleate-capped iron oxide nanoparticles to an aqueous phase upon treatment with a base bath cleaning solution. We discuss the mechanism of the phase transfer, which involves the elimination of the organic capping agent followed by ionic stabilization of the nanoparticles due to negatively charged Fe-O- surface species. The resultant superparamagnetic aqueous nanocolloid shows excellent protein immobilization capability.status: publishe

Gold nanorods 3D-supercrystals as surface enhanced Raman scattering spectroscopy substrates for the rapid detection of scrambled prions

Highly organized supercrystals of Au nanorods with plasmonic antennae enhancement of electrical field have made possible fast direct detection of prions in complex biological media such as serum and blood. The nearly perfect three-dimensional organization of nanorods render these systems excellent surface enhanced Raman scattering spectroscopy substrates with uniform electric field enhancement, leading to reproducibly high enhancement factor in the desirable spectral range

Facile synthesis and electrochemical properties of octahedral gold nanocrystals

High-yield octahedral gold nanocrystals of *45 nm in size have been facilely synthesized by one-pot reduction of HAuCl4 using formic acid in cetyltrimethylammonium bromide (CTAB) aqueous solution. The results showed that CTAB can promote the formation of single-crystalline nucleation and preferentially adsorb on the (111) planes of gold nanocrystals, resulting in the formation of octahedral gold nanocrystals. Formic acid acted as not only a mild reducing agent, but also could promote the formation of (111) facet. The octahedral gold nanocrystals exhibited similar cyclic voltammetry (CV) curves to single-crystal Au (111) electrode and excellent electrocatalytic activity for methanol oxidation. This synthetic strategy may open new route for facile synthesis of shape-controlled metal nanoparticles