Development of a test strip based on DNA-functionalized gold nanoparticles for rapid detection of mercury(II) ions

A rapid,sensitive,selective and reliable strip assay based on DNA-functionalized gold nanoparticles for Hg²⁺ detection has been developed,with a detection limit 5 nmol/L.The measurement principle was based on thymine-Hg²⁺-thymine(T-Hg²⁺-T) coordination chemistry and streptavidin-biotin interaction.The major advantages of this assay are that results can be read visually without any instrument in less than 10 min and that it does not require any sample pretreatment.     

Quantitative Separation of Hg(11) From Several Metal Ions on Zr(IV) Antimonate Papers

Abstract

The chromatographic behaviour of 32 metal ions has been studied on paper Impregnated with Zirconium(IV) antimonate in aqueous HCI and mixed solvent system containing dimethyisul phoxide and dioxane. Several Important binary and ternary separations have been achieved. Quantitative separation of Hg(ll) from Ni²⁺, Pb²⁺, Pd²⁺, Ru³⁺, Rh³⁺, Bi³⁺, Co²⁺, Cd²⁺ and Gd³⁺ is described.     

On the redox reactions of radicals with AlIII(phthalocyaninate) pendants covalently bonded to poly(ethyleneamide). Mechanistic alterations when radicals are formed inside pockets of micelle‐like polymer aggregates

The mechanisms of the redox reactions between a polymer containing Al(III) sulfonated phthalocyanine pendants, (Al^III(^?NHS(O₂)trspc)^2?)₂, and radicals have been investigated in this work. Pulse radiolysis and photochemical methods were used for these studies. Oxidizing radicals, OH^?, HCO₃^?, (CH₃)₂COHCH₂^?, and N₃^?, as well as reducing radicals, e_aq^?, CO₂^??, and (CH₃)₂C^?OH, respectively accept or donate one electron forming pendent phthalocyanine radicals, Al^III(^?NHS(O₂)trspc ^?)^{? or 3?}. The kinetics of the redox processes is consistent with a mechanism where the pendants react with radicals formed inside aggregates of five to six polymer strands. Electron donating radicals, that is, CO₂^?? and (CH₃)₂C^?OH, produce one‐electron reduced phthalocyanine pendants that, even though they were stable under anaerobic conditions, donated charge to a Pt catalyst. While the polymer was regenerated in the Pt catalyzed processes, 2‐propanol and CO₂ were respectively reduced to propane and CO. The reaction of SO₃^?? radicals with the polymer stood in contrast with the reactions of the radicals mentioned above. A first step of the mechanism, the coordination of the SO₃^?? radical to the Al(III), was subsequently followed by the formation of a SO₃^?? ‐ phthalocyanine ligand adduct. The decay of the SO₃^?? ‐ phthalocyanine ligand adduct in a ～10² ms time domain regenerates the polymer, and it was attributed to the dimerization/disproportionation of SO₃^?? radicals escaping from the aggregates of polymer. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

PbII 4,4,4-trifluoro-1-naphthyl-1,3-butanedione complexes of 1,10-phenanthroline and 2,2′-bipyridine ligands

Lead(II) 4,4,4-trifluoro-1-naphthyl-1,3-butanedione (Htfnb) complexes of 1,10-phenanthroline (phen) and 2,2′-bipyridine (bpy), [Pb₂(bpy)₂(tfnb)₂] (1) and [Pb₂(phen)₂(tfnb)₂] (2), have been synthesized and characterized by elemental analysis, IR, spectroscopy and X-ray crystallography. The self-assembly of 1 and 2 is likely to be caused by C–H ··· F–C, C–H ··· O and π–π stacking interactions.     

Spectroscopic studies and crystal structure of a dimeric Zn(II) complex with diethyl (pyridin-2-ylmethyl)phosphate

The crystal structure of [Zn₂(2-pmOpe)₂Cl₄] (2-pmOpe?=?diethyl (pyridin-2-ylmethyl)phosphate) was determined by X-ray-diffraction method. The compound was also characterized by IR, far-IR, 1H, and ³¹P NMR spectroscopy. In this compound, 2-pmOpe is a bidentate N,O-bridging ligand and Zn(II) are slightly distorted tetrahedral ZnNOCl₂. Zn(II) ions are doubly bridged by the 2-pmOpe ligands, resulting in a dinuclear species. The structure is stabilized by intermolecular C–H?···?O and C–H?···?Cl hydrogen bonds. The spectral properties are in agreement with the structural data.     

Synthesis,structure, spectral and magnetic properties of 4-methoxy- and 3-methylsalicylatocopper(II) complexes with 2-pyridylmethanol

The synthesis and characterization of [Cu(4-MeOsal)₂(2-pyme)₂] (1) and [Cu(3-Mesal)₂(2-pyme)₂] (2) (where 4-MeOsal?=?4-methoxysalicylate, 3-Mesal?=?3-methylsalicylate and 2-pyme?=?2-pyridylmethanol) are reported. The composition and stereochemistry as well as the mode of coordination have been determined by elemental analysis, IR, electronic and EPR spectra as well as magnetization measurements over the temperature range 1.8–300?K. The crystal structures of Cu(4-MeOsal)₂(2-pyme)₂ and Cu(3-Mesal)₂(2-pyme)₂ have been determined.     

Antibacterial activity assays of a new cadmium complex with o-phenanthroline and cyanoguanidine: crystal structure,fluorescence properties,and chemical speciation studies

A new coordination complex, aqua bis(o-phenanthroline) cadmium(II) sulfate cyanoguanidine pentahydrate, [Cd(o-phen)₂(SO₄)(H₂O)](cnge)?·?5H₂O, was synthesized and characterized. The crystal structure was solved by X-ray diffraction methods. It crystallizes in the monoclinic space group P2₁/n with a?=?13.7650(2) Å, b?=?10.2796(2) Å, c?=?21.4418(3) Å, β?=?90.106(2)°, and Z?=?4 molecules per cell unit. The cadmium(II) is in a distorted octahedral environment coordinated to two nearly planar and mutually perpendicular o-phenanthrolines, one oxygen atom of sulfate, and a water molecule. Non-bonded and planar cyanoguanidine and five crystallization water molecules complete the asymmetric unit. Vibrational (FT-IR and FT-Raman) spectroscopies and thermogravimetric determinations support this structure. Intensity enhancement of the fluorescence spectrum may be a demonstration of the interaction of the metal with phenanthroline. In solution the coordination behavior is rather different, and the speciation studies point to coordination of both cnge and phenanthroline to cadmium. The improvement of the antibacterial activity of cadmium upon complexation has been determined.