Development of a chromium speciation probe based on morphology-dependent aggregation of polymerized vesicle-functionalized gold nanoparticles.

In this work, a new approach for visual sensing of Cr3+ in aqueous solutions is presented, based on the morphological changes induced by Cr3+ on (4-carboxybenzyl)bis[2-(undec-10-enyloxycarbonyl)ethyl]methylammonium bromide (4-CBUAB)-polymerized vesicles. CTAB-stabilized gold nanoparticles (GNPs) react with 4-CBUAB-polymerized vesicles to form aggregates via vesicle-micelle interactions, which does not proceed further because of vesicle-vesicle repulsive forces, creating a large polymerized vesicle-gold nanoparticle (PV-GNP) conjugate. The incorporation of Cr3+ through the 4-CBUAB polymeric membrane induces structural perturbations on the polymerized vesicle morphology by swelling of the lamellar phase which is reflected in the morphology of the polymerized vesicle-gold nanoparticle conjugate assembly.

Indirect chemiluminescence-based detection of mefenamic acid in pharmaceutical formulations by flow injection analysis and effect of gold nanocatalysts.

A highly sensitive flow injection-chemiluminescence detection (FI-CL) method based on periodate oxidation of two popular luminescent compounds for the determination of mefenamic acid (MFA) is presented. The method is an indirect CL detection method based on the CL emission generated during the oxidation of Pyrogallol (Pg) or Luminol (Lu) with the excess of periodate that remains after oxidation of MFA within the time period of 15 min. The MFA calibration curves obtained with either luminescent compounds were linear over a wide concentration range, depending on the system employed, offering detection limits in the range of low to ultra-low microg L(-1) levels.

Coacervation of surface-functionalized polymerized vesicles derived from ammonium bromide surfactants. Application to the selective speciation of chromium in environmental samples.

The potential of polymerized vesicle coacervates made up of ammonium bromide surfactants for the extraction of metallic ions from natural waters was examined for the first time. Linear linked polymerized vesicles prepared by UV excitation of (4-carboxybenzyl)bis[2-(10-undecenoyloxy)ethyl]methylammonium bromide monomer were characterized, and several factors affecting their phase behavior were investigated. Evidently, the permeation of metallic elements through the polymeric membrane was found to be sensitive to ionic radius excluding ions larger than the interbilayer space of the vesicle assembly.

Polyoxomolybdenum(V/VI)-sulfite compounds: synthesis, structural, and physical studies.

Reaction of Na(2)Mo(VI)O(4) x 2H(2)O with (NH(4))(2)SO(3) in the mixed-solvent system H(2)O/CH(3)CN (pH = 5) resulted in the formation of the tetranuclear cluster (NH(4))(4)[Mo(4)(VI)SO(16)] x H(2)O (1), while the same reaction in acidic aqueous solution (pH = 5) yielded (NH(4))(4)[Mo(5)(VI)S(2)O(21)] x 3H(2)O (2). Compound {(H(2)bipy)(2)[Mo(5)(VI)S(2)O(21)] x H(2)O}(x) (3) was obtained from the reaction of aqueous acidic solution of Na(2)Mo(VI)O(4) x 2H(2)O with (NH(4))(2)SO(3) (pH = 2.5) and 4,4'-bipyridine (4,4'-bipy).