Modified screen-printed electrodes for the investigation of the interaction of non-electroactive quinazoline derivatives with DNA

Five morpholino-quinazoline derivatives have bern investigated voltammetric ally using a competition with the tris(o-phenanthroline) cobalt(III) redox marker for the accumulation at dsDNA modified screen-printed electrodes. An association of quinazolines with DNA was observed at the modified electrod es polarized by the negative potential of -0.4 V vs. AE/AgCl. This was conf irmed by a potentiometric stripping analysis based on the DNA guanine signa l. Calibration curves for quinazolines within a concentration range of mu m ol/L were obtained with DP voltammetry using 5 x 10(-7) mol/L Co(phen)(3)(3 +) marker. The quinazolines exhibit no effect on the DNA complex with the f luorescent thiazole orange derivative TO-PRO-3. The role of the accumulatio n potential in the association interaction with DNA is discussed.