In the present study a chitosan/ionic liquid modified pencil graphite electrode (CHIT‐IL‐PGEs) was developed for the first time for enhanced electrochemical monitoring of nucleic acid, and the interaction of the anticancer drug Mitomycin C (MC) and calf thymus double stranded DNA (dsDNA) by measuring the oxidation signals of MC and guanine in the same voltammetric scale. Differential pulse voltammetry, cyclic voltammetry and electrochemical impedance spectroscopy techniques were used to evaluate the performance of the CHIT‐IL based biosensor on electrochemical monitoring of DNA, and drug‐DNA interaction. The experimental parameters, IL, dsDNA and MC concentration and the interaction time were then optimized.

In this paper, the application of a Graphene oxide (GRPox) integrated on single-use pencil graphite electrode (PGE) for the enhanced monitoring of nucleic acids and for the sensitive and selective detection of the label free DNA hybridization related to Hepatitis B virus (HBV) sequences is described. Electrochemical behaviors of GRPox modified PGEs were firstly investigated using electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). The sequence selective DNA hybridization was determined voltammetrically in the case of hybridization between amino linked probe and its complementary (target), or, noncomplementary (NC), or target/mismatch (MM) mixtures (1 : 1).