Application of an Electrochemical Sensor Based on Multi-Walled Carbon Nanotubes Modified Platinum Electrode for Determination of Doxorubicin in Biological Fluids and Preliminary Study on Drug-DNA Interactions

In this work, an electrochemical sensor was fabricated based on multi-walled carbon nanotubes modified platinum electrode (Pt/MWCNTs) for determination of doxorubicin as a chemotherapydrug. Doxorubicin effectively accumulated on the surface of Pt/MWCNTs and caused a pair ofredox peaks at around 0.522 and 0.647 V (vs. Ag/AgCl) in Britton Robinson buffer (pH 4.0, 0.1M). The electrochemical parameters including pH, kind of buffer, accumulation time, amount ofmodifier and scan rate have been optimized. Under the optimum conditions, there was a linearcorrelation between cathodic peak current and concentration of doxorubicin in the range of 0.2 to 4.0 g L-1 with the detection limit of 0.02 g L-1. The number of electron transfers (n) andelectron transfer-coefficient (α) were estimated as 2.0 and 0.5 respectively. The constructed sensor displayed excellent precision, sensitivity, repeatability and selectivity in the determination of doxorubicin in plasma. Moreover, cyclic voltammetry studies of doxorubicin in the present of DNA showed an intercalation mechanism with binding constant (K) of 1.12 x 105 L mol-1.

Keywords:

Doxorubicin , MWCNTs , Electrochemical Sensor , Plasma , DNA study