DNA sensor for o-dianisidine.

J Jasnowska; M Ligaj; B Stupnicka; M Filipiak

doi:10.1016/j.bioelechem.2004.03.004

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DNA sensor for o-dianisidine.

J Jasnowska·M Ligaj·B Stupnicka·M Filipiak

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Abstract

o-Dianisidine (3,3'-dimethoxybenzidine) is applied in the production of some dyes and also used in analytical tests. However, this compound is anticipated to be a human carcinogen. An analytical strategy utilizing square wave voltammetry for the determination of o-dianisidine is presented. An electrochemical system was consisted of three electrodes: carbon paste working electrode, platinum wire counter electrode and silver-silver chloride (Ag/AgCl) reference electrode. However, square wave voltammograms of direct measurements of o-dianisidine were found to be hardly reproducible, exhibiting few peaks due to some labile short-lived intermediates with the only exception of a quite stable peak at +0.7 V vs. Ag/AgCl. Quantitative determination of o-dianisidine gave satisfactory results only when the carbon paste working electrode was replaced by deoxyribonucleic acids (DNA) electrode obtained by immobilization of double-stranded (ds) DNA on carbon electrode. Square wave voltammogram of DNA showed two peaks attributed to adenine and guanine and the latter was used as analytical signal. After interaction with o-dianisidine, guanine oxidation peak was reduced to the extent related to the concentration of the analyte. Initial reduction of guanine peak took place already at the concentration of o-dianisidine equal to 0.4 microM; high concentrations (above 100 microM) of the analyte quenched completely a guanine response. The presented electrochemical system enables a specific detection of o-dianisidine by the presence of an oxidation peak at +0.7 V and its quantitative determination by measuring a reduction of guanine peak by means of a DNA sensor.

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Adenine Animals Biosensing Techniques Calibration Carbon Coloring Agents DNA Dianisidine Electrochemistry Electrodes Guanine Humans Oxidation-Reduction Potentiometry Silver Silver Compounds Journal Article

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J Jasnowska, M Ligaj, B Stupnicka, M Filipiak. 2004. DNA sensor for o-dianisidine.. https://doi.org/10.1016/j.bioelechem.2004.03.004

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