Evaluation of the interactions of DNA with the textile dyes Disperse Orange 1 and Disperse Red 1 and their electrolysis products using an electrochemical biosensor

摘要

A disposable pencil graphite electrode modified with ds DNA was used in combination with square wave voltammetry in order to evaluate the interaction of DNA with the textile dyes Disperse Orange 1 (DO1) and Disperse Red 1 (DR1), and with the products of their electrolysis. Significant changes in the charac teristic oxidation peaks of the guanine and adenine moieties of immobilized dsDNA were observed after incubation of the modified electrode for 180 s in solutions of the dyes in their original forms. The same was observed using the electrolysis products obtained by oxidation and reduction conversions. The oxidation peak currents of the guanine and adenine moieties decreased when the concentrations of D01 and DR1 were increased up to 5.0 × 10~(-6) and 1.0 × 10~(-6)mol L~(-1), respectively; the signal decreases were more pro nounced after interaction with the oxidized dyes, compared to the reduced compounds. The interactions between DNA and DOl, DR1, and the electrolyzed dyes were further investigated by UV-vis spectropho-tometry in solution, and different effects such as hypochromism and hyperchromism were observed in the resulting DNA spectra. The investigated interactions showed clear evidence of changes in the DNA structure, and suggested a predominant intercalation mode leading to damage in the biomolecule.