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Novel Reactive Groups for Modification DNA by Oxoosmium Complexes
Havran, Luděk; Vidláková, Pavlína; Špaček, Jan; Hermanová, Monika; Fojta, Miroslav
2017 - English
DNA is naturally electroactive moleclue producing several intrinsie voltammetric signals. Some of them found appliction in electrochemical analysis of DNA interactions and damage. In particular types of applictaions is a suitable use DNA labelling by redox active tags to increase selectivity and sensitivity of analysis.One type of long-term used tags are complexes of osmium tetroxide with nittrogen ligunds (Os,L). These complexes preferentially react with pyrimidines in single stand DNA producing electractive adducts. primary reaction site for Os,L is C-C double bond in pyrimidine nucleobases. In this contribution will be presented results acquired with DNA containing chemically modified nuclebase.
Keywords:
nucleic-acids; osmium; Chemically modified DNA; Oxoosmium complexes
Available at various institutes of the ASCR
Novel Reactive Groups for Modification DNA by Oxoosmium Complexes
DNA is naturally electroactive moleclue producing several intrinsie voltammetric signals. Some of them found appliction in electrochemical analysis of DNA interactions and damage. In particular types ...
2D Condensation of 5-Fluorocytosine in Different Electrolytes
Fojt, Lukáš; Fojta, Miroslav
2017 - English
Two-dimensional (2D) condensation and adsorption of 5-fluorocytosine on hanging mercury drop electrode in differnt electrolytes was investigated. We have used different sodium halide salts as basic electrolytes. The influence of electrolytes composition was displayed using differential capacitance measurements. Effects of ions present in used electolytes solution was remarkable. We observed huge change in 2D condensed layers in dependence on ions type.
Keywords:
2-dimensional condensation; mercury-electrode; adsorption; interface
Available at various institutes of the ASCR
2D Condensation of 5-Fluorocytosine in Different Electrolytes
Two-dimensional (2D) condensation and adsorption of 5-fluorocytosine on hanging mercury drop electrode in differnt electrolytes was investigated. We have used different sodium halide salts as basic ...
Limitations and Possibilities of Nanostructurized Silver Amalgam
Daňhel, Aleš; Šebest, Peter; Vidláková, Pavlína; Ligmajer, Filip
2017 - English
Variability of silver amalgam offers a row of opportunities for its application in electrochemical and spectroelectrochemical methods, thanks to its chemical, mechanical, electrochemical and spectrometric properties. This work briefly revews preparation possibilities and limitations of nanostructurized crystalas and nanopartices pf silver amalgam at different forms of carbon metals (Ag, Au, Pt) and transparent materials (ITO, FTO). These detection sysytems are in the scope of ongoing systematics research with the potential to indevelopment of novel working (micro)electrodes and spectroelectrochemical cells, potentially utilizable in modern (bio)analytical applictions.
Keywords:
nanoparticles based electroanalysis; voltammetric determination; electrochemical sensors; chemical carcinogens
Available at various institutes of the ASCR
Limitations and Possibilities of Nanostructurized Silver Amalgam
Variability of silver amalgam offers a row of opportunities for its application in electrochemical and spectroelectrochemical methods, thanks to its chemical, mechanical, electrochemical and ...
Effect of Thymine and Cytosine Nucleobase Sequence on the Two-Dimensional Condensation of Pyrimidine Oligodeoxynucleotides at Mercury Surface
Hasoň, Stanislav; Fojta, Miroslav
2017 - English
The aim of this contribution is study the effect of thymine and cytosine nucleobase composition (different lengths and/or repeat segments of either thymine or cytosine units or their combinations) within a set of the oligodeoxynucleotide (ODN) chains on the two-dimensional of homo- and hetero-pyrimidine ODNs at mercury electrode surface. It was shown that pyrimidine ODNs containing eight and more pyrimidine nucleobases can form, at negatively charged Hg surface (around1.32 V vs. Ag/AgCl), two different 2D condensed films characterized by the differential capacitances of about 9.4 (I-2D) and 7.6 mu F cm(-2) (II2D) respectively.
Keywords:
phase transients; water interface; nucleic-acids; adsorption
Available at various institutes of the ASCR
Effect of Thymine and Cytosine Nucleobase Sequence on the Two-Dimensional Condensation of Pyrimidine Oligodeoxynucleotides at Mercury Surface
The aim of this contribution is study the effect of thymine and cytosine nucleobase composition (different lengths and/or repeat segments of either thymine or cytosine units or their combinations) ...
Determination of a Novel Antimycobacterial Agent in a Single Drop of a Solution by Voltammetry at a Glassy Carbon Electrode
Gajdar, J.; Goněc, T.; Jampílek, J.; Brázdová, Marie; Bábková, Zuzana; Fojta, Miroslav; Barek, J.; Fischer, J.
2017 - English
One of the novel antimycobacterial agents from the group of hydroxynaphthalene carboxamides (namely I-hydroxy-X-(4-nitrophenyl)naphthalene-2-carboxamide) was investigated using voltammetric methods for the first time. The study was carried out at a glassy carbon electrode by methods of cathodic and anodic differential pulse voltammetry in micro volumns (20 mu L) of an aqueous solution at pH 7 containing 10% dimethyl sulfoxide and in a real matrix of a bacterial growth medium. The miniaturized method was compared with the macro volume determination. The presence of oxygen in micro volumes presents the biggest obstacle for the miniaturized method.
Keywords:
herbicidal activity; antibacterial; system; I-hydroxy-N-(4-nitrophenyl)naphthalene-2-carboxamide
Available at various institutes of the ASCR
Determination of a Novel Antimycobacterial Agent in a Single Drop of a Solution by Voltammetry at a Glassy Carbon Electrode
One of the novel antimycobacterial agents from the group of hydroxynaphthalene carboxamides (namely I-hydroxy-X-(4-nitrophenyl)naphthalene-2-carboxamide) was investigated using voltammetric methods ...
Electrochemically Switchable DNA Tags
Vidláková, Pavlína; Havran, Luděk; Fojta, Miroslav
2017 - English
DNA labelling is used for the improvement of sensitivity and selectivity of its electrochemical detection. Attachment of a new electroactive group into DNA strand can give rise to a new electrochemical signal. For analysis of label DNA is often advantageous to use redox tags giving reversible redox signal because of the possibility of performing several repeated measurements with one sample. Some redox tags give reversible redox signal directly in their introduced forms. Reduction/oxidation of other redox tags is irreversible but reduction/oxidation of these groups can give rise to new groups that yield reversible electrochemistry.
Keywords:
nucleoside triphosphates; enzymatic incorporation; Voltammetry; dna
Available at various institutes of the ASCR
Electrochemically Switchable DNA Tags
DNA labelling is used for the improvement of sensitivity and selectivity of its electrochemical detection. Attachment of a new electroactive group into DNA strand can give rise to a new ...
Constant Current Chronopotentiometry as a Method for Detection of Singlet Oxygen Protein Damage
Ostatná, Veronika; Vargová, Veronika; Černocká, Hana; Paleček, Emil
2016 - English
Proteins are one of the major targets for oxidative damage in the cell.Indirect non-radical oxidation of the protein via formation and subsequent reaction with single oxygen (O-1(2))is one of the major processes.In this work we studied the single oxygen(O-1(2))-mediated oxidation of bovine serum albumin (BSA) by constant current chronopotentiometry in combination with mercury electrode.Our chronopotentiometric data show that photo-oxidized BSA was more susceptible to the electric field-induced denaturation than non-oxidized native BSA. Our method utilizing intrinsic electrochemical signal of proteins provides a sensitive detection methods for minor damages in various proteins.
Keywords:
carbon electrodes; affinity tags; mercury; purification
Available at various institutes of the ASCR
Constant Current Chronopotentiometry as a Method for Detection of Singlet Oxygen Protein Damage
Proteins are one of the major targets for oxidative damage in the cell.Indirect non-radical oxidation of the protein via formation and subsequent reaction with single oxygen (O-1(2))is one of the ...
Voltammetric determination of 1-hydroxy-N-(4-nitrophenyl)naphthalene-2-carboxamide by voltammetry at a glassy carbon electrode in microvolumes of dimethyl sulfoxide
Gajdar, J.; Goněc, T.; Jampílek, J.; Brázdová, Marie; Bábková, Zuzana; Fojta, Miroslav; Barek, J.; Fischer, J.
2016 - English
Voltammetric reduction and oxidation of 1-hydroxy-N-(4-nitrophenyl) naphthalene-2-carboxamide was investigated at glassy carbon electrode in dimethyl sulfoxide. Cyclic voltammetry was used to investigate the mechanism of reduction of nitro group and oxidation of hydroxyl group. The analyte was successfully determined in dimethyl sulfoxide by differential pulse voltammetry and the whole voltammetric procedure was miniaturised. Square wave voltammetry was employed to reduce the interference from dissolved oxygen. Determination in one drop (20 mu L) of 0.1 mol L-1 tetrabutyl-ammonium tetrafluoroborate in dimethyl sulfoxide provided very similar results compared to determination in the bulk solution. Limits of quantification were 5.0 mu mol L-1 for cathodic voltammetry and 5.3 mu mol L-1 for anodic voltammetry.
Keywords:
herbicidal activity; antibacterial; oxidation
Available at various institutes of the ASCR
Voltammetric determination of 1-hydroxy-N-(4-nitrophenyl)naphthalene-2-carboxamide by voltammetry at a glassy carbon electrode in microvolumes of dimethyl sulfoxide
Voltammetric reduction and oxidation of 1-hydroxy-N-(4-nitrophenyl) naphthalene-2-carboxamide was investigated at glassy carbon electrode in dimethyl sulfoxide. Cyclic voltammetry was used to ...
Amalgam Electrodes Pretreatment and Electrochemical Analysis of DNA
Daňhel, Aleš; Fojta, Miroslav
2016 - English
Mercury meniscus silver solid amalgam electode (m-AgSAE) represents the most suitable and perspective alternative to mercury electrodes which excel in sensitivity to biopolymers and their structural changes. This work briefly summarizes factors influencing electrochemical analysis of DNA at mercury and amalgam electrodes and it is mainly devoted to development of suitable pretreatment procedure, which could securte repeatable and reliable measurements of DNA at m-AgSAes. The results are essential for further utilization of amalgam electrodes in developement of biosensors, since DNA samples are very strongly adsorbed at the electrodes, and none pretreatment procedure was found to be successful in their complete desorption.
Keywords:
double-helical polynucleotides; electrically charged surfaces; mercury-electrode; silver amalgam
Available at various institutes of the ASCR
Amalgam Electrodes Pretreatment and Electrochemical Analysis of DNA
Mercury meniscus silver solid amalgam electode (m-AgSAE) represents the most suitable and perspective alternative to mercury electrodes which excel in sensitivity to biopolymers and their structural ...
Voltammetry of 1-Hydroxy-N-(4-nitrophenyl)naphthalene-2-carboxamide at a Glassy Carbon Electrode
Gajdar, J.; Goněc, T.; Jampílek, J.; Brázdová, Marie; Bábková, Zuzana; Fojta, Miroslav; Barek, J.; Fischer, J.
2016 - English
This electrochemical study is aimed at an investigation of a reaction mechanism and determination of 1-hydroxy-N-(4-nitrophenyl)naphthalene-2-carboxamide in media with various amount of an organic solvent (dimethyl sulfoxide or methanol). The studied analyte is a model substance from a group of recently prepared drugs with antibiotic characteriss Mechanism of reducible nitro group and oxidisable hydroxyl group is compared with studies of substructures and structurally similar compounds. Preliminary comparison of different media was carried out to find the best parameters for the determination.
Keywords:
herbicidal activity; antibacterial; nitrobenzene; oxidation
Available at various institutes of the ASCR
Voltammetry of 1-Hydroxy-N-(4-nitrophenyl)naphthalene-2-carboxamide at a Glassy Carbon Electrode
This electrochemical study is aimed at an investigation of a reaction mechanism and determination of 1-hydroxy-N-(4-nitrophenyl)naphthalene-2-carboxamide in media with various amount of an organic ...
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