Investigation of copper oxidation states in plasmonic nanomaterials by XAS and Raman spectroscopy.

Plasmonic core-shell-isolated nanoparticles are promising nanoplatforms for photocatalysis and for low detection analysis. This paper describes the characterization of a 2,2'-bipyridine phosphonate functionalized Ag@TiO nanocomposite which complexes copper ions by enhanced Raman spectroscopy and X-ray absorption (XANES and EXAFS). We distinguished Cu(i) from Cu(ii) complexes using shell-isolated nanoparticle enhanced Raman (SHINERS) combined with XAS spectroscopy.

Functionalized core-shell Ag@TiO nanoparticles for enhanced Raman spectroscopy: a sensitive detection method for Cu(ii) ions.

This paper demonstrates the use of surface plasmon resonance of core-shell Ag@TiO2 particles in SHINERS experiments. A copper(ii) complex grafted onto Ag@TiO2 surface was probed by Raman spectroscopy using resonance excitation profiles vs. excitation wavelengths (514, 633 and 785 nm) to tune the Raman signals.

Non-photochemical catalytic hydrolysis of methyl parathion using core-shell Ag@TiO nanoparticles.

Highly water-dispersible core-shell Ag@TiO nanoparticles were prepared and shown to be catalytically active for the rapid degradation of the organothiophosphate pesticide methyl parathion (MeP). Formation of the hydrolysis product, -nitrophenolate was monitored at pH 7.5 and 8.

Phosphonate-Mediated Immobilization of Rhodium/Bipyridine Hydrogenation Catalysts.

RhL complexes of phosphonate-derivatized 2,2'-bipyridine (bpy) ligands L were immobilized on titanium oxide particles generated in situ. Depending on the structure of the bipy ligand-number of tethers (1 or 2) to which the phosphonate end groups are attached and their location on the 2,2'-bipyridine backbone (4,4'-, 5,5'-, or 6,6'-positions)-the resulting supported catalysts showed comparable chemoselectivity but different kinetics for the hydrogenation of 6-methyl-5-hepten-2-one under hydrogen pressure. Characterization of the six supported catalysts suggested that the intrinsic geometry of each of the phosphonate-derivatized 2,2'-bipyridines leads to supported catalysts with different microstructures and different arrangements of the RhL species at the surface of the solid, which thereby affect their reactivity.

Comparison of Zirconium Phosphonate-Modified Surfaces for Immobilizing Phosphopeptides and Phosphate-Tagged Proteins.

Different routes for preparing zirconium phosphonate-modified surfaces for immobilizing biomolecular probes are compared. Two chemical-modification approaches were explored to form self-assembled monolayers on commercially available primary amine-functionalized slides, and the resulting surfaces were compared to well-characterized zirconium phosphonate monolayer-modified supports prepared using Langmuir-Blodgett methods. When using POCl3 as the amine phosphorylating agent followed by treatment with zirconyl chloride, the result was not a zirconium-phosphonate monolayer, as commonly assumed in the literature, but rather the process gives adsorbed zirconium oxide/hydroxide species and to a lower extent adsorbed zirconium phosphate and/or phosphonate.