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1.
Dalton Trans ; 44(19): 8833-8, 2015 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-25864923

RESUMEN

Ni-catalyzed electroreductive olefin perfluoroalkylation affords both monomeric and dimeric products depending on the reaction media. Recycling of the catalyst can be achieved by immobilization of a (bpy)NiBr2 complex on silica nanoparticles decorated with anchoring amino-groups. Switching the homogeneous and heterogeneous catalysts is found to be one more factor to control the product ratio. This catalytic technique is both green and atom economical and combines the advantages of nanoheterogeneous catalysis and electrocatalysis.

2.
Langmuir ; 31(1): 611-9, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25511410

RESUMEN

The present work introduces the easy modification of the water-in-oil microemulsion procedure aimed at the doping of the Tb(III) complexes within core or shell zones of the silica nanoparticles (SNs), which are designated as "core-shell", "shell", and "core". The dye molecules, chelating ligands, and copper ions were applied as the quenchers of Tb(III)-centered luminescence through dynamic or/and static mechanisms. The binding of the quenchers at the silica/water interface results in the quenching of the Tb(III) complexes within SNs, which, in turn, is greatly dependent on the synthetic procedure. The luminescence of "core" SNs remains unchanged under the binding of the quenchers at the silica/water interface. The quenching through dynamic mechanism is more significant for "core-shell" and "shell" than for "core" SNs. Thus, both "core-shell" and "shell" SNs have enough percentage of the Tb(III) complexes located close to the interface for efficient quenching through the energy transfer. The quenching through the ion or ligand exchange is most efficient for "core-shell" SNs due to the greatest percentage of the Tb(III) complexes at the silica/water interface, which correlates with the used synthetic procedure. The highlighted regularities introduce the applicability of "core-shell" SNs used as silica beads for phosphatidylcholine bilayers in sensing their permeability toward the quenching ions.


Asunto(s)
Nanopartículas/química , Dióxido de Silicio/química , Terbio/química , Cobre/química , Ligandos , Sustancias Luminiscentes/química , Mediciones Luminiscentes , Compuestos Organometálicos/química , Fosfatidilcolinas/química , Agua/química
3.
Colloids Surf B Biointerfaces ; 115: 93-9, 2014 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-24333558

RESUMEN

The work introduces the quenching of silica coated Tb(III) complexes by merocyanine 540 (MC540) and copper ions as a tool to reveal the adsorption of phosphatidylcholine (PC) and phosphatidylserine (PS) at various PS:PC ratio onto silica nanoparticles doped with Tb(III) complex. The binding of MC540 with PC-based bilayers and copper ions with PS-based ones are the basis of their use as organic and inorganic probes to sense PS:PC ratio in silica supported mixed bilayers. The enrichment of mixed bilayers by PS results in the displacement of MC540 anions, while it enhances the binding with copper ions. The displacement or binding of probe ions results in the diverse luminescence response of Tb(III)-centred luminescence. The reestablishment of the steady state and time resolved luminescence is observed, when MC540 anions are applied as probes. The use of copper ions as probes results in the opposite quenching effect. The developed route enables to discriminate the formation of the phospholipids bilayers onto silica surface from those in the bulk of solution under various concentration conditions.


Asunto(s)
Transferencia de Energía , Membrana Dobles de Lípidos/química , Fosfatidilcolinas/química , Fosfatidilserinas/química , Dióxido de Silicio/química , Absorción , Coloides/química , Cobre/química , Iones , Microscopía de Fuerza Atómica , Pirimidinonas/química , Soluciones , Espectrometría de Fluorescencia , Terbio/química
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