Abstract:
© 2015 Elsevier B.V. All rights reserved. New approach of the detection of anthracycline preparations intercalating native DNA has been proposed and realized in the assembly of electrochemical sensor. Glassy carbon was covered with polyaniline obtained by electropolymerization in the presence of native DNA and oxalic acid as doping agents. As was shown by impedimetric and voltammetric measurements, the surface coating obtained showed extended pH range of electrochemical activity and retained ability to interact with specific intercalators. The incubation of the sensor with anthracycline preparations resulted in regular decrease of electron transfer resistance and suppression of redox probe current (ferricyanide anion). In optimal conditions, the detection limits of 0.01 nM doxorubicin, 0.1 nM daunorubicin and 0.2 nM idarubicin were achieved. The replacement of oxalic acid with sulfuric acid as polymerization media as well as thermal denaturation of DNA resulted in disappearance of the response. The selectivity of DNA interaction detection was higher in weakly acidic media for impedimetric measurements and in HEPES, pH 7.0, for voltammetric detection. Albumin, blood plasma electrolytes and sulfanylamides do not interfere with anthracycline measurements. The electrochemical sensor developed was tested in the determination of doxorubicin in commercial preparation with 91-93% recovery.
