Národní úložiště šedé literatury Nalezeno 4 záznamů.  Hledání trvalo 0.02 vteřin. 
Amalgam Electrodes Pretreatment and Electrochemical Analysis of DNA
Daňhel, Aleš ; Fojta, Miroslav
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.
Effect of Thymine and Cytosine Nucleobase Sequence on the Two-Dimensional Condensation of Pyrimidine Oligodeoxynucleotides at Mercury Surface
Hasoň, Stanislav ; Fojta, Miroslav
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.
Reduction of the DNA at a Pyrolytic Graphite Electrode:Opening of the Second Half of the Potential Window
Špaček, Jan ; Daňhel, Aleš ; Hasoň, Stanislav ; Hejduková, M. ; Fojta, Miroslav
The pyrolytic graphite electrode (PGE) can be used at highly negative potentials, providing reduction signals known from mercury-based electrodes. Use of the negative part of the potential window more than doubled the number of analytically useful signals provided by unlabelled DNA on PGE. It enables selective analysis of all canonical DNA bases,5-methylcytosine and uracil It also allows for distinction of overlapping signals cathodic polarization can selectively ´switch off´ DNA anodic signals and rice versa. Newly observed signals corresponding to oxidation of reduced bases and reduction of oxidized bases are also described.
Study of Synthetic Oligonacleotides Containing Guanine by Voltammetry on a Graphite Electrode
Hejduková, M. ; Špaček, Jan ; Fojta, Miroslav ; Havran, L. ; Renciuk, D.
Electrochemical oxidation of specifically designed DNA hexamers containing guanine has been studied in aqueous acetate buffet (pH 5) at a pyrolytic graphite electrode (PGE) by linear sweep voltammetry (LSV) Influence of the oligonucleotide composition and concentration was investigated It seems that short oligonucleotides containing guanine produce oxidation signals. which are sensitive to their structural properties Simple electrochemical techniques us may be useful tool for monitoring of structural changes of DNA.