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Electrochemical properties of thiol monolayers at surfaces of different electrodes
Josypčuk, Bohdan ; Mareček, Vladimír
Solid amalgam electrodes covered by a mercury meniscus or by mercury film (m-AgSAE, MF-AgSAE, m-CuSAE, m-BiAgSAE and m-CdSAE) are convenient for obtaining thiol films which are bound to different metals. By choosing an appropriate metal for the amalgam preparation, a thiol monolayer can be created which is stable in the given potential range. After a short accumulation time (1-2 min), the area of the reduction peak (charge) practically does not change it the monolayer is created from 1 nM thiol solution. Statistical results based on many times repeated formation and desorption of thiol monolayers (RSD = 2-3 %) attest that the stationary SAEs are convenient tools for study of electrochemical properties of thiol films.
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Preparation and Properties of Mercury Films on Solid Amalgam Surface
Josypčuk, Bohdan
There have been suggested a simple electrolyzer and a reliable procedure for preparation of mercury films with precisely defined thickness on a conducting surface. A small volume of electrolyte which can be used more times and a paste amalgam which cannot spill substantially decrease a risk of environment contamination. Measurements were parallelly performed on a liquid mercury free silver solid amalgam electrode (AgSAE), on a mercury meniscus modified AgSAE and on HMDE for comparing their properties with those of the mercury film electrodes (MF-AgSAE). A current response of the film electrodes is the biggest. The peak width, which determines the method resolution, is smallest on the film electrodes. Range of working potentials on MF-AgSAE is comparable with one on HMDE in different supporting electrolytes.
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Electrochemical detection of trace amounts of nitrated explosives
Barek, J. ; Fischer, J. ; Vyskočil, V. ; Pecková, K. ; Navrátil, Tomáš ; Josypčuk, Bohdan
Nitrated organic compounds belong to the group of the most frequently used explosives. Detection of low levels of such compounds is very attractive in these days. Due to the easy reducibility of the nitro group, voltammetry seems to be very suitable method for these purposes. For these determinations the following electrodes were used: were used hanging mercury drop electrode, meniscus modified silver solid amalgam electrode, miniaturized paste silver amalgam electrode, paste electrode on the basis of silver amalgam powder and proper organic liquid were used.
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Voltametrické stanovení sloučenin dusíku pomocí stříbrné pevné amalgámové elektrody
Daňhel, A. ; Barek, J. ; Josypčuk, Bohdan ; Pecková, K.
Silver amalgam is a good electrode material for construction of new types of electrodes. In this work a silver solid amalgam paste electrode was prepared. The pastes were mixed from a silver solid amalgam powder and a mineral oil, silicone oil, paraffin oil and tricresylphosphate, stuffed into a Teflon body of electrode. The silver paste amalgam electrodes are expected to provide new possibilities for determinations of electrochemically reducible compounds by modern voltammetric methods. The main expected advantage is the possibility of easily renewable surface as in the case of carbon paste electrodes.
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The use of prototype of multichannel device for electrochemical detection of DNA hybridization
Brázdilová, P. ; Navrátil, Tomáš ; Josypčuk, Bohdan ; Fojta, Miroslav
The article presents newly constructed 8-channel device, which enables sequential analysis realized on up to 8 different or equal sensors. The device is computer controlled. The screen-printed carbon electrodes (SPCE) were connected to the device. DNA hybridization was detected. DNA present in the sample spontaneously adsorbed on the surface of SPCE and free surface was subsequently blocked using beef serum albumin. The adsorbed DNA was then hybridized with the probe marked with biotin and streptavidin conjugated with enzyme alkaline phosphatase (SALP). This enzyme catalyzes the transformation of electrochemically inactive 1-naphtylphosphateone 1-naphtol, which anodic signal was detected DC voltammetry (DCV).
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Composite solid amalgam electrodes
Lukina, A. ; Josypčuk, Bohdan ; Navrátil, Tomáš ; Pecková, K. ; Barek, J.
Preparation and first results achieved by composite silver solid amalgam electrodes (AgSA-CE) are presented. Polished, film as well as mercury meniscus modifications of these electrodes were studied by determination of p-nitrophenol, lead, cadmium, iodades, adenine, ascorbic acid and other compounds.
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Determination of herbicide dinoseb with amalgam and carbon electrodes
Fischer, J. ; Barek, J. ; Pecková, K. ; Zima, J. ; Kücükkolbasi, S. ; Ersöz, M. ; Kara, H. ; Josypčuk, Bohdan ; Navrátil, Tomáš
Dinoseb, systematically 2-(1-methylpropyl)-4,6-dinitro-phenol, is phenolic, commonly used herbicide and insecticide. Dinoseb has two very easy reducible nitro-groups in its structure and one electrochemically oxidizable hydroxy group. Differential pulse voltammetry was applied for its determination in water. The nitro group reduction was used for voltammetric determination with hanging mercury electrode (HMDE), mercury film electrode (MFE) and modified carbon paste electrode (MCPE) and carbon paste electrode (CPE) as well as meniscus modified silver solid amalgam electrode (m-AgSAE).
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