A disposable copper (II) ion biosensor based on self-assembly of L-cysteine on gold nanoparticle-modified screen-printed carbon electrode was fabricated. The electrode was modified by attaching gold nanoparticles onto the surface of screen-printed carbon electrode through seed mediated growth method followed by self-assembly of L-cysteine. As demonstrated by differential pulse voltammetry, the ...

The structure of [Cu(tpen)](ClO4)2 (tpen = N,N,N',N'-tetrakis(2-pyridylmethyl)-1,2-ethanediamine) has been identified by X-ray crystallography. The copper(II) ion is surrounded by two amine N atoms and three pyridine N atoms of the ligand, making a distorted trigonal-bipyramid. Among the six potential N donor atoms (two amine N and four pyridine N atoms), only one pyridine N atom remains uncoor...

A simple and rapid spectrophotometric method for the determination of oxalate ion was established by the fading of a colored complex between N,N'-diethyl-N,N'-[[4,4'-dihydroxy-1,1'-binaphthalene]-3,3'-diyl]bisbenzamide and copper(II). Beer's law was obeyed in the concentration range of 0.1 - 2.0 microg cm(-3) for oxalate ion, with an effective molar absorptivity at 533 nm and the relative stand...

The copper(II) complex [Cu(pic)2]·2H2O was synthesized with 2-picolinic acid (Hpic) and copper acetate as reactants by room temperature solid-solid reaction. The composition and structure of the complex was characterized by elemental analyses, single crystal X-ray diffraction, X-ray powder diffraction, FT-IR spectroscopy and thermogravimetry-differential scanning calor...

in this paper, two double helical dinuclear copper(ii) complexes of bis-n,o-bidentate schiff base ligands bis(3-methoxy-n-salicylidene-4,4'-diaminodiphenyl)sulfone (l1) and bis(5-bromo-n-salicylidene-4,4'-diaminodiphenyl)sulfone (l2) were prepared and characterized by elemental analyses (chn), as well as thermal analysis. elemental analyses (chn) suggested that the reaction between ligands and ...

Copper (II) is a biologically active essential ion and it forms the active centers in several metalloenzymes and proteins. Its chelating ability and positive redox potential allow participation in biological transport reactions. The copper atom transforms between the Cu(I) and Cu(II) oxidation states in redox reactions involving copper containing enzymes. This is an essential factor for many of...

Replacement of the catalytic Zn(II) in horse liver alcohol dehydrogenase (HLADH) with copper produces a mononuclear Cu(II) chromophore with a ligand set consisting of two cysteine sulphurs, one histidine nitrogen plus one further atom. The fourth ligand to the metal ion and the conformation of the protein may be altered by addition of exogenous ligands and/or the cofactor NADH. Absorbance, CD, ...

Copper has many roles in biology that involve the change of coordination sphere and/or oxidation state of the copper ion. Consequently, the study of copper in heterogeneous environments is an important area in biophysics. EPR is a primary technique for the investigation of paramagnetic copper, which is usually the isolated Cu(II) ion, but sometimes as Cu(II) in different oxidation states of mul...

In this article, preparation of polypyrrole and its nanocomposites as adsorbents werediscussed and the capability of separation of copper ions from aqueous solution were studied.Polypyrrole was prepared by chemical oxidative polymerization method of pyrrole usingFeCl3 as an oxidant. The removal of Cu (II) was investigated using PPy, PPy/TiO2 andPPy/TiO2/DHSNa nanocomposites. The products were i...

Evidence is growing to support a functional role for the prion protein (PrP) in copper metabolism. Copper ions appear to bind to the protein in a highly conserved octapeptide repeat region (sequence PHGGGWGQ) near the N terminus. To delineate the site and mode of binding of Cu(II) to the PrP, the copper-binding properties of peptides of varying lengths corresponding to 2-, 3-, and 4-octarepeat ...