Electrochemical Biosensors Based on Native DNA and Nanosized Mediator for the Detection of Anthracycline Preparations

A novel electrochemical DNA-sensor based on glassy carbon electrode (GCE) modified with electropolymerized Neutral red (NR) and polycarboxylated thiacax[4]arene with covalently attached mediator and electrostatically adsorbed DNA was developed for sensitive detection of anthracycline preparations. Intercalation of doxorubicin, daunorubicin and idarubicin into DNA increases the charge transfer resistance and decreases the electron exchange resulted in decay of the cathodic peak of NR reduction. The DNA-sensor developed makes it possible to determine down to 0.05nM doxorubicin, o.1nM doxorubicin and 0.5nM idarubicin. The DNA-sensor was tested on detection of doxorubicin in pharmaceuticals and artificial blood plasma with 95-100% recovery.