Tomasz Rebis

One-step synthesis of lignosulfonate-stabilized silver nanoparticles

Softwood lignosulfonate (SLS) was used as a reducing agent for one-step synthesis of silver nanoparticles (SLS-AgNPs) in an aqueous solution at room temperature. In this reaction SLS acts also as a stabilizing agent and as a result, stable colloids of silver nanoparticles are formed during the reaction with the average particle size of 41 nm. The obtained SLS-AgNPs were characterized by UV-vis spectrophotometry, size distribution and AFM imaging after casting on mica. Due to metal ion complexing capability of lignosulfonates, the SLS-AgNPs appeared to be capable of colorimetric detection of metal ions (especially nickel). Additionally, the SLS-AgNPs could be assembled into thin films on conducting substrates (ITO glass) using electrophoretic deposition. XPS spectroscopy was used to characterize such films and revealed a strong interaction of silver atoms with some carbon atoms of the SLS.

Synthesis and Electroanalytical Performance of a Composite Material Based on Poly(3,4-ethylenedioxythiophene) Doped with Lignosulfonate

3,4-ethylenedioxythiophene (EDOT) was electropolymerized in the presence of sodium lignosulfonate (LS) at constant current density of 0.25 mA cm−2. As a result, a thin composite film consisting of poly(3,4-Ethylenedioxythiophene) and LS (PEDOT/LS) was deposited on the electrode surface. Unlike PEDOT, PEDOT/LS shows appreciable redox activity due to LS-derived quinone moieties with diffusion-like charge propagation across the film thickness. The film-modified gold electrodes can be used as voltammetric sensor of uric acid (UA) in the presence of ascorbic acid (AA). Interestingly, the UA response is catalysed by the presence of AA, and for high AA/UA concentration ratios more than 10-fold enhancement of the UA peak currents are apparent.

Magnesium(II) 1-(1-adamantylsulfanyl)phthalocyanine – synthesis, photochemical and electrochemical properties

A mixed macrocyclization reaction of 3-(1-adamantylsulfanyl)-1,2-dicyanobenzene and 1,2-dicyanobenzene led to unsymmetrical magnesium(II) 1-(1-adamantylsulfanyl)phthalocyanine. The novel macrocycle was characterized using UV-Vis, MS MALDI and NMR spectroscopy. The spectroscopic study of solvatochromic effects indicated that the changes observed in the electronic absorption spectra are mainly a result of solvation, and that the coordinating strength of the solvent had little influence on the red shift. The novel magnesium(II) phthalocyanine derivative revealed in DMF and DMSO the fluorescence quantum yield (Φf) values of 0.30 and 0.35, and singlet oxygen quantum yield (ΦΔ) values of 0.32 and 0.25, respectively. The magnesium(II) phthalocyanine derivative displayed in the voltammetric study four sets of redox peaks, two one-electron oxidations, and two one-electron reductions, which were assigned to ring based one electron processes.

Multiwalled carbon nanotube/sulfanyl porphyrazine hybrids deposited on glassy carbon electrode — effect of nitro peripheral groups on electrochemical properties

We report on the synthesis, MS, UV-vis, NMR, HPLC and electrochemical characterization of magnesium sulfanyl porphyrazine with 2-[2-(4-nitrophenoxy)ethoxy]ethylsulfanyl substituents in the periphery. The electrochemical properties of novel macrocycle were studied by cyclic voltammetry and differential pulse voltammetry in non-aqueous electrolyte. The experimental data indicated the occurrence of clearly defined four redox couples corresponded to one-electron reactions of the π-conjugated porphyrazine ring and substituents in the periphery. Multiwalled carbon nanotube/sulfanyl porphyrazine hybrids deposited on a glassy carbon electrode allowed for the evaluation of the effect of nitro peripheral groups on the electrochemical properties. The electrochemical behavior of immobilized nitro porphyrazine was consistent with the reduction mechanism for the various arylnitro compounds in aqueous media, with two processes characteristic of the redox transitions of the arylnitro group to the corresponding arylhydrox...