A Sensitive Electrochemical DNA Biosensor for Anticancer Drug Topotecan Based on Graphene Carbon Paste Electrode

A main anti-cancer medicine is topotecan (TPT), which is a water-soluble derivative of camptothecin. TPT is so effective for treatment of human ovarian cancer, cervical and small cell lung cancer [1].Some methods have been applied to determine topotecan and only a few voltammetric methods was used to study the electrochemical behavior of topotecan. The study of interactions between drug and DNA is of present overall interest and importance, particularly to design novel DNA-targeted medicines. Among the methods used to study the interaction between DNA and drug, electrochemical techniques are particularly promising because of their high sensitivity and selectivity along with reasonably low costs [2]. Graphene is a low-cost substance with excellent mechanical, electrical and thermal features and it has been recently considered considerably. Owing to mentioned features, graphene is a good alternative for using in electrochemical biosensor [3].In current research, the interaction of topotecan with DNA is investigated with a graphene paste electrode and in solution phase via DPV. Based on the interaction between dsDNA and topotecan, topotecan was determined by a simple, fast, reliable, and sensitive DNA biosensor. After optimizing the main experimental parameters, This DNAcoated GPE was fabricated to evaluate its performance analytically. A linear dynamic range of 7.0×10-7– 9.0×10-5 M was obtained for topotecan. Ultimately, the proposed biosensor was found to be capable of successfully analyzing human serum and urine samples.