phi YeO3-12 phage tail fiber Gp17 as a promising high specific tool for recognition of Yersinia enterocolitica pathogenic serotype O : 3

Yersiniosis is an infectious zoonotic disease caused by two enteropathogenic species of Gram-negative genus Yersinia: Yersinia enterocolitica and Yersinia pseudotuberculosis. Pigs and other wild and domestic animals are reservoirs for these bacteria. Infection is usually spread to humans by ingestion of contaminated food. Yersiniosis is considered a rare disease, but recent studies indicate that it is overlooked in the diagnostic process therefore the infections with this bacterium are not often identified. Reliable diagnosis of Yersiniosis by culturing is difficult due to the slow growth of the bacteria easily overgrown by other more rapidly growing microbes unless selec-tive growth media is used. Phage adhesins recognizing bacteria in a specific manner can be an excellent diagnostic tool, es-pecially in the diagnosis of pathogens difficult for culturing. In this study, it was shown that Gp17, the tail fiber protein (TFP) of phage phi YeO3-12, specifically recognizes only the pathogenic Yersinia enterocolitica serotype O:3 (YeO:3) bacteria. The ELISA test used in this work confirmed the specific interaction of this protein with YeO:3 and demonstrated a promising tool for developing the pathogen recognition method based on phage adhesins.Peer reviewe

Hydrogen Peroxide Generation at Liquid|Liquid Interface under Conditions Unfavorable for Proton Transfer from Aqueous to Organic Phase

The charge transfer processes across the interface between two immiscible electrolyte solutions (ITIES) can be employed for energy storage and conversion, solvent extraction, or sensing or in life sciences. Among them are catalytic reactions, which have only been recently studied. Here H2O2 generation is studied with decamethylferrocene (DMFc) as electron donor at the interface between tetrahexylammonium perchlorate solution in 1,2- dichloroethane (1,2-DCE) and aqueous HClO4. These conditions are unfavorable for proton transfer across ITIES because of positive Galvani potential difference. Voltammetry with 1,2-DCE droplet modified electrode shows that DMFc oxidation is accompanied by ClO4− insertion into the organic phase. The reaction progress was followed by UV−vis spectroscopy, voltammetry, and scanning electrochemical microscopy (SECM). In the first and last method, horseradish peroxidase was used as catalyst. It is concluded that O2 is reduced to H2O2 at the liquid|liquid interface not only under conditions when proton transfer to organic phase is strongly favored, namely, when Galvani potential difference is negative (Angew. Chem., Int. Ed. 2008, 47, 4675−4678)

Ion transfer processes at ionic liquid based redox active drop deposited on an electrode surface

International audienc

Hydrogen Peroxide Generation at Liquid|Liquid Interface under Conditions Unfavorable for Proton Transfer from Aqueous to Organic Phase

The charge transfer processes across the interface between two immiscible electrolyte solutions (ITIES) can be employed for energy storage and conversion, solvent extraction, or sensing or in life sciences. Among them are catalytic reactions, which have only been recently studied. Here H₂O₂ generation is studied with decamethylferrocene (DMFc) as electron donor at the interface between tetrahexylammonium perchlorate solution in 1,2-dichloroethane (1,2-DCE) and aqueous HClO₄. These conditions are unfavorable for proton transfer across ITIES because of positive Galvani potential difference. Voltammetry with 1,2-DCE droplet modified electrode shows that DMFc oxidation is accompanied by ClO₄^– insertion into the organic phase. The reaction progress was followed by UV–vis spectroscopy, voltammetry, and scanning electrochemical microscopy (SECM). In the first and last method, horseradish peroxidase was used as catalyst. It is concluded that O₂ is reduced to H₂O₂ at the liquid|liquid interface not only under conditions when proton transfer to organic phase is strongly favored, namely, when Galvani potential difference is negative (Angew. Chem., Int. Ed. 2008, 47, 4675−4678)

Characterisation of biphasic electrodes based on the liquid N,N-didodecyl-N ' N '-diethylphenylenediamine redox system immobilised on porous hydrophobic silicates and immersed in aqueous media

Biphasic electrodes based on the water-insoluble redox liquid N,N-didodecyl-N,N'-diethylphenylene-diamine (DDPD) neat and dissolved in di-(2-ethyl-hexyl)phosphate (HDOP) deposited onto silicate matrices were prepared and studied in aqueous electrolyte media. As electrode substrates (i) bare gold, (ii) a gold surface covered with a hydrophobic silicate film, and (iii) a hydrophobic silicate carbon composite were employed. Both hydrophobic silicate based materials act as a host for the organic redox liquid and modify the electrochemical response in characteristic manner. The electrooxidation of DDPD occurs at the organic phase\aqueous phaselelectrode triple phase boundary and is accompanied by the transfer of the anion from the water into the organic phase. In the presence of an organic acid, HDOP, the oxidation process is accompanied by the expulsion of protons instead. This electrochemically driven proton exchange process results in a shift of redox potentials, which can be described by Nernst-type dependence with a slope strongly dependent on the electrode/host material and the deposition method. The formation of an DDPD-HDOP acid-base complex within microdroplets deposited deposited on gold surfaces is confirmed by IR reflectance spectra. (C) 2005 Elsevier B.V. All rights reserved