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Electrochemical reduction of oxygen on the copper electrode with adsorbed polymers is investigated. The polymers serve as models of hydrophilic sides of bio-membranes and namely are: polyacrylamide (PAA), albumin and poly aniline (PANI). It is determined that adsorption of PANI and PAA decreases the double electric layer capacity of the copper cathode and adsorption of albumin increases it. It is shown that the PANI and PAA adsorbed on an electrode, unlike the albumin, facilitate reduction of molecular oxygen by accelerating formation of its active forms (AFO). Suggestions about the mechanism of influence of nature of polymers on the process of electrochemical reduction of oxygen and AFO are expressed and discussed. [ABSTRACT FROM AUTHOR]

In this paper, we propose to use nanocrystalline ZnO electrodes, obtained through zol-gel and electrochemical methods, as a sensitive element of dissolved oxygen sensor. We elucidate that electrodes have stable characteristics at electroreduction O2 in biological solutions. The average size of the obtained particles d makes up ~ 102 nm. We determine the quantity of electrons on the discharge stage and the total quantity of electrons, participating in restoration reaction of oxygen. Furthermore, we study the influence of environment on characteristics of the obtained electrodes and choose the material for additional electrode of oxygen sensor. Relying on the research results, we create the laboratory model of an electrochemical sensor for measuring the concentration level of oxygen in biological liquids. Taking into consideration the level of electrochemical noise, we estimate the sensor sensitivity to the dissolved oxygen ((6-15)·10-8 mol/l). The accuracy of concentration measurements O2 made 5-8 %, speed -- 5-7 s. [ABSTRACT FROM AUTHOR]