Ni(II)-Salophen-Comprehensive Analysis on Electrochemical and Spectral Characterization and Biological Studies.

New aspects of the Ni(II)-salophen complex and salophen ligand precursor were found during deep electrochemical and optical characterization, as well as biological studies for new pharmacological applications. Physicochemical and spectroscopic methods (1H- and 13C-NMR, FT-IR and UV-Vis, electrospray ionization mass spectroscopy, thermogravimetric analysis, and molar conductance measurements) were also used to prove that the salophen ligand acts as a tetradentate and coordinates to the central metal through nitrogen and oxygen atoms. The electrochemical behavior of the free Schiff salophen ligand (H2L) and its Ni(II) complex (Ni(II)L) was deeply studied in tetrabutylammonium perchlorate solutions in acetonitrile via CV, DPV, and RDE. Blue films on the surfaces of the electrodes as a result of the electropolymerization processes were put in evidence and characterized via CV and DPV. (H2L) and Ni(II)L complexes were tested for their antimicrobial, antifungal, and antioxidant activity, showing good antimicrobial and antifungal activity against several bacteria and fungi.

Nickel-foam-supported ß-Ni(OH)2 as a green anodic catalyst for energy efficient electrooxidative degradation of azo-dye wastewater.

Electrochemical oxidative degradation (EOD) is a particularly promising technique for removing organic pollutants from wastewater. However, due to the high overpotential of EOD in conventional anode materials, the energy cost of EOD is usually very high, which greatly promotes the search for highly active, stable, and energy-efficient anodic catalysts. Herein, we demonstrated that nickel-foam-supported (NF-supported) ß-Ni(OH)2 (NF/ß-Ni(OH)2) prepared via a facile hydrothermal method could be used as an energy efficient anode for EOD. The as-prepared 3D porous NF/ß-Ni(OH)2 exhibited high activity toward the electrochemical oxidation of methyl orange (MO) in the low potential region (<1.07 V vs. SCE). This property differs greatly from those of the conventional anode materials that require a high positive potential to keep them active for EOD, making NF/ß-Ni(OH)2 an energy-efficient and active anode material for EOD. With an oxidation current density of 0.25 mA cm-2, the decolorization of MO was completed within 30 min, and the COD removal after 3h of reaction was 63.0%. The normalized energy consumption for the 3 h degradation of MO was 22.2 kW h (kg COD)-1, which is only a fraction of (or even one tenth of) the values reported in the literature. Moreover, NF/ß-Ni(OH)2 had a good stability and recyclability for EOD. No activity decay was observed during 10 h of EOD and the COD removal remained almost unchanged after four consecutive reaction cycles. We demonstrated experimentally that the NF/ß-Ni(OH)2 anode could generate large amounts of hydroxyl radicals and that the oxidation of MO by hydroxyl radicals was the main mechanism during EOD. We believe that this work opens a new avenue for developing highly active and energy-efficient anode materials that can work in the low potential region for EOD.

Stochastic sensors designed for assessment of biomarkers specific to obesity.

Two stochastic sensors based on the following oleamides: 1-adamantyloleamide and N,N-dimethyl-N-(2-oleylamidoethyl)amine physically immobilized on graphite paste were designed. The sensors were able to determine simultaneously from the whole blood of Wistar rats three biomarkers specific to obesity: leptin, interleukin-6 (IL-6) and plasminogen activator inhibitor 1 (PAI-1). The whole blood samples were obtained from Wistar rats treated with oleoylethanolamide (OEA), (Z)-N-[(1S)-2-hidroxy-1-(phenylmethyl) ethyl]-9octadecenamide (OLA), and with the aqueous solution of 1% Tween 80 used as solvent for oleamides formulations (control samples). The proposed sensors were very sensitive and reliable for the assay of obesity biomarkers in whole blood of rats.

Permeability improvements of electropolymerized polypyrrole films using dissolvable nano-CaCO3 particle templates.

The electropolymerisation of N-substituted pyrroles on a dissolvable calcium carbonate nanoparticle template was investigated in order to improve the film permeabilities in aqueous solution. After deposition of CaCO3 nanoparticles on the electrode surface, poly(pyrrole-ammonium) or poly(pyrrole-NTA) (NTA: nitrilotriacetic acid) were electrogenerated around the template structures of the electrodes using potentiostatic methods. The dissolution of nanoparticles in acidic medium leads to the formation of nano-porous structures increasing, therefore, the polypyrrole permeability in aqueous solutions. Histidine-tagged glucose oxidase, chosen as an enzyme model, was immobilised on the modified polypyrrole-NTA via the NTA-Cu(2+)-histidine interactions to validate the proposed method. The described setup led to a twofold increase in the maximum current density from 5 to 10 µA cm(-2) after template dissolution.

Study of the complexation of 1,3-diethyl 2-(azulen-1-ylmethylene)propanedioate with lanthanide cations.

This work is devoted to the electrochemical characterization of 1,3-diethyl 2-(azulen-1-ylmethylene)propanedioate by cyclic voltammetry and differential pulse voltammetry. The redox processes are established, analyzed and assessed to the particular functional groups at which they take place. The complexation behavior towards lanthanide metal ions (Sm(3+), Eu(3+), Yb(3+), Tb(3+)) was studied by electrochemical methods and UV-Vis spectroscopy.