Oxidation-Reduction Potentials Measured with the Dropping Mercury Electrode

1945 ◽  
Vol 87 (1) ◽  
pp. 441 ◽  
Author(s):  
Otto H. Müller
Keyword(s):  
Mercury Electrode ◽  
Reduction Potentials ◽  
Oxidation Reduction ◽  
Dropping Mercury Electrode

Absence of unwinding of double-helical DNA in the surface of mercury electrode charged to DNA reduction potentials at neutral pH

1979 ◽  
Vol 44 (2) ◽  
pp. 448-455 ◽  
Author(s):  
Emil Paleček ◽  
Sianette Kwee
Keyword(s):  
Conformational Changes ◽  
Electrode Surface ◽  
Mercury Electrode ◽  
Linear Sweep Voltammetry ◽  
Reduction Product ◽  
Potential Range ◽  
Acid Media ◽  
Reduction Potentials ◽  
Dropping Mercury Electrode ◽  
Neutral Media

The influence of adsorption of DNA on its double-stranded (ds) structure was studied with the aid of hanging mercury drop electrode (HMDE) in neutral media. Changes in DNA reducibility followed by linear sweep voltammetry served as an indication of the DNA conformational changes in the electrode surface. It has been shown that, due to contact of ds DNA with the electrode for periods many times longer than those which can be reached at the dropping mercury electrode, extensive surface denaturation of DNA can be detected only in a narrow potential range around -1.2 V. At potentials more negative than this region neither surface denaturation nor blocking of the electrode by the reduction product were observed. On the other hand, interaction of the denatured DNA with the mercury surface under the same conditions, resulted in blocking of the electrode surface by the reduction product. In agreement with the previous studies in acid media similar blocking of the surface was observed at pH 5 both with thermally denatured and ds DNAs. On the basis of the experimental data the following conclusions have been drawn: i) in neutral media the course of interfacial events of DNA is strongly dependent on DNA conformation and differs from the course suggested for acid media; ii) the deduction concerning the behavior of ds DNA on the electrode in neutral media made by other authors on the basis of their measurements in acid media is not justified.

Reduction and tensammetric pulse-polarographic currents of polynucleotides

1987 ◽  
Vol 52 (11) ◽  
pp. 2810-2818 ◽  
Author(s):  
Emil Paleček ◽  
František Jelen ◽  
Vladimír Vetterl
Keyword(s):  
Diagnostic Criteria ◽  
Pulse Width ◽  
Mercury Electrode ◽  
Pulse Amplitude ◽  
Single Strand ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode ◽  
Adenylic Acid ◽  
Drop Time

The behaviour of electrochemically reducible single-strand polynucleotides (poly(adenylic acid)) and poly(cytidylic acid)) was studied by the differential (derivative) pulse polarography (DPP) and by other methods. Measurements were performed with the help of the dropping mercury electrode under various conditions specified by the pulse width, pulse amplitude, drop time etc. For the faradaic and tensammetric DPP peaks the diagnostic criteria were proposed which make it possible to classify even very small DPP peaks of double helical polynucleotides.

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