Voltammetric DNA Sensor Based on Redox-Active Dyes for Determining Doxorubicin

We proposed a voltammetric DNA sensor based on glassy carbon modified with carbon black, pillar[5]arene, and electropolymerized Neutral Red. To increase signal sensitivity, Methylene Blue in monomeric and polymeric forms was introduced into the surface layer of the DNA sensor as a specific DNA intercalator and electron transfer mediator. The electrochemical characteristics of the coating are determined, depending on the composition and the preparation method; a consistent change in the peak currents of dyes is observed during the incubation of a DNA sensor in a solution of doxorubicin as a model anticancer drug. Under optimal conditions, the DNA sensor enables the determination of 10 nM to 0.1 mM of doxorubicin. Doxorubicin can also be determined in synthetic blood plasma.