Ex situ Voltammetry and Chronopotentiometry of Doxorubicin at a Pyrolytic Graphite Electrode: Redox and Catalytic Properties and Analytical Applications

Ex situ (adsorptive transfer stripping) electrochemical techniques in connection with basal‐plane PGE have been applied to the study of redox and catalytic properties of doxorubicin (DOX). Cyclic and square‐wave voltammetry and constant current chronopotentiometric stripping (CPS) analysis were used to follow reversible reduction of DOX quinone moiety around ?0.5 V and its coupling to catalytic oxygen reduction. CPS was for the first time used for sensitive ex situ determination of the DOX using the catalytic signal around ?0.5 V in the presence of oxygen, allowing detection of femtomole amounts of DOX. We show that specific interaction of DOX with double‐stranded DNA can easily be monitored using the catalytic CPS signal.