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Electrochemical Deposition of Silver Amalgam Particles on Pyrolitic Graphite Electrode
Šebest, Peter ; Havranová-Vidláková, Pavlína ; Ligmajer, Filip ; Fojta, Miroslav ; Daňhel, Aleš
Silver solid amalgam represents suitable alternative electrode material to metallic mercury, Controlled electrodeposition of variable silver amalgam particles (AgAP) on the surface of pyrolitic graphite electrode from an electrolyte containing Agt It and Hg(II) ions is reported as a novel method suitable lot preparation of perspective supporting materials Scanning electron microscopy including energy-disperse X-ray spectrometer and image processing software were used for analysis of composition and morphology of AgAP on POE A model electrochemically reducible 4-niirophenol was used to test a potential applicability of AgAp-PGE in electroanalytical methods.
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Preparation and Characterization of Silver Amalgam Particles on Gold Electrode Surface
Havranová-Vidláková, Pavlína ; Šebest, Peter ; Ligmajer, Filip ; Fojta, Miroslav ; Daňhel, Aleš
This work is focused on the preparation of silver amalgam particles by its direct electrodeposition on gold surfaces using double pulse chronoamperometry from solution containing soluble Ag+ and Hg2+ ionts. During the electrodepositions of silver amalgam particles, different: i) parameters of chronoamperometry, ii) Ag/Hg ratio in solution and iii) gold electrodes were studied. All the prepared amalgam particles were characterized by scanning electron microscope with energy dispersive X-ray spectroscopy and electrochemical methods. Voltammetric application of the gold electrodes decorated by sliver amalgam particles was confirmed by analysis of model organic nitrocompound using cyclic voltammetry.
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Electrochemical Study of Osmium Tetroxide Comptests Reactivity to DNA Bearing Butylacrylate
Havran, Luděk ; Havranová-Vidláková, Pavlína ; Špaček, Jan ; Vítová, Lada ; Hermanová, Monika ; Fojta, Miroslav
Coniplexes of osmium tetroside with nitrogen ligands (Os,L e.g.. with 2,2'-bipyridine (bpy) find application in redox labelling of DNA.. probing of DNA structure, and in studies of DNA interaction with other molecules Os,L preferentially react with pyrimidines in single strand DNA producing electroactive adducts Primary reaction site for Os,L is C=C double bond in pyrimidine nucleobases. In this contribution we introduce a new two-step technique of DNA modification with Os,bpy, consisting in enzymatic construdion or DNA beating butyl acrylate (BA) moieties attached to uracil or T-deaza adenine, followed by chemical modification of a reactive C=C double bond in BA residue.
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Voltammetric Detection of Purine Nucleobases on Screen-Printed Graphite Electrodes Modified by Nanocarbon Materials
Hasoň, Stanislav ; Ostatná, Veronika ; Fojta, Miroslav
Recent studies have shown that the electrochemical oxidation of purine nucleobases (adenine and geaoine) at graphite electrodes is strongly dependent on the orientation of graphene sheets. their size and mutual distribution on the electrode surface. Edges and defects of graphene sheets affect the kinetics of oxidation processes, basal planes support the adsorption processes The aim of this study is to determine how model carbon nanomaterials including graphene, single-walled or multi-wailed carbon nanotubes. carbon nanofibres and mesoporous graphene affect the electrochemical oxidation or purine nuclebases on screen-printed carbon electrodes modified by these nanostructures in solution without and in the presence of copper.
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Electrochemical Investigation of Different Boron Cluster Compounds in Water-based Electrolytes
Fojt, Lukáš ; Vespalec, Radim ; Fojta, Miroslav ; Grüner, Bohumír
Boron cluster compounds (BCC) belongs to one or the proud sing compounds which ace used for medical treatment Their use for biochemical purposes is connected with use of water-based environments. Up to now, the BCC were predominantly characterized in non-aqueous milieus Therefore, we decided to undertake electrochemical research of BCC in water-based electrolytes. We have investigated several boron clusters with structures containing different number of vertexes (from 3 to 18), The structures were modified by endo- and exo- skeletal substituents. All used BCC were electrochemically active in broad potential region. which implies their possible use as biomarkers with tunable electrochemical response.
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Searching for Electrochemical Reduction Mechanism of Azidophenyl DNA Labels
Daňhel, Aleš ; Trošanová, Zuzana ; Balintová, Jana ; Hocek, Michal ; Fojta, Miroslav
This contribution brings new information to sporadic scientific results concerned to electrochemical reduction of aromatic azides. Selected compounds used as perspective DNA labels or their structural constituents such as, 4-azidophenyltrifluoroboronic acid, 4-azidophenyl modified deoxycytidine and next probable analogous compounds and/or products of their reduction, were voltammetrically studied and compared to each other in order to reveal a mechanism of their electrochemical reduction at mercury electrodes in aqueous media. Preliminary results obtained by cyclic voltammetry at mercury and carbon based electrodes and by mass spectrometry of the products isolated from batch electrolysis on mercury pool by preparative chromatography are discussed.
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Voltametrická analýza nukleosidtrifosfátů a oligonukleotidů značených antrochinonem na zlatých elektrodách
Vidláková, Pavlína ; Balintová, Jana ; Havran, Luděk ; Hocek, Michal ; Fojta, Miroslav
Elektrochemická aktivita nukleových kyselin byla objevena v 50. letech 20. století a od té doby je používána ke studiu struktury a interakcí přirozených i modifikovaných molekul nukleových kyselin i syntetických oligonukleotidů. Přestože je přirozená DNA sama o sobě elektrochemicky aktivní a je možné ji studovat na různých typech elektrod, je pro řadu analytických aplikací praktické použít DNA značenou elektroaktivními molekulami (například komplexy přechodných kovů, amino- nebo nitroskupinami, antrachinonem apod.). Tyto látky podléhají redoxním reakcím a dávají takto modifikované DNA nové elektrochemické vlastnosti, které je možné využít pro studium struktury a interakcí nukleových kyselin a v oblasti DNA diagnostiky.
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