1IntroductionElectrochemical investigationo ft he interaction between anticancer drugs and DNAh as been of growing interest becauset he pre-and postelectrochemical signalso ft he surface confinedi nteraction between DNAa nd drugs provideg ood evidencef or the interaction mechanism to be clarified. Anticancer drugs interactw ith DNAi ns everal ways such as non-covalent groove binding, covalent binding/cross-linking, DNAc leaving and nucleosideanalog incorporation [1][2][3].T hese interaction mechanisms have been researched using different techniques [4][5][6]. Electrochemical approaches have been successfully utilized since discovery of electrochemistry of nucleic acids [7].E lectrochemical techniques offera nalyzingo ft he target not only sensitively and selectively but also more practical and in as horter time compared to the conventional methods [3].T hus,e lectrochemicalt echniques have been widely used for development of DNAb iosensors includingm onitoring of drug-DNAi nteractions [2,8,9]."Nanotechnology" term was introduced in the middle of 20 th century by Richard Feynman. Aftert hen, different forms of nanomaterials such as nanoparticles,n anofibers, nanowires,n anorods and nanotubesh ave been developed by researchers usingn anotechnology [10].D evelopment of nanomaterials based biosensing platforms have been an attractive topicdue to their unique electrical, mechanical, optical and physochemical properties.M oreover, they providet od etect the target sensitively regarding their high surface area. In this manner,c arbon nanotubes have been widely studied for development of biosensors due to their high surface area, hollow geometry,e lectrical, mechanical properties [11][12][13].Thea pplications of carbon nanotube modified electrochemical biosensor for the purpose of monitoring of drug-DNAi nteraction have been reported [14][15][16][17].M oreover, the combinations of carbonn anotubes with different polymers have been reported in the literature [18][19][20][21][22][23][24][25][26][27].Chitosan (CHIT)i sal inear hydrophilic polysaccharide and biological cationic macromolecule with primary amines.Its good biocompatibility,n on-toxicity,b iodegradability and film-forming ability [28] promote its usage in biomedical applications,especially biosensors [22][23][24].Thea ntibiotic mitomycin C(MC) is an antitumor agent usedi nc linical chemotherapya gainst ab road spectrum of solid tumors.E arly studies indicatedt hat the primary target of the MC action is DNA, as evidenced by its ability to bind covalently to DNA, both mono and bifunctionally [29].M onitoring the MCÀDNAi nteraction process was reported in earlier studies in literaturew ith different electrochemicald etection methods and transducers [30-Abstract:Amultiwalled carbonn anotubes (CNT)-chitosan (CHIT) modified pencil graphite electrode( CNT-CHIT/PGE) wasd eveloped for the first time herein for electrochemical monitoring of the interaction of an anticancer drug,m itomycin C( MC) and DNA. Thec haracterization of unmodified PGE, CHIT/PGE,C NT/PGE and CHIT-C...

In this present study, ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate (IL)) modified pencil graphite electrode (IL-PGEs) was developed for electrochemical monitoring of DNA hybridization related to Microcystis spp. (MYC). The characterization of IL-PGEs was performed using microscopic and electrochemical techniques. DNA hybridization related to MYC was then explored at the surface of IL-PGEs using differential pulse voltammetry (DPV) technique. After the experimental parameters were optimized, the sequence-selective DNA hybridization related to MYC was performed in the case of hybridization between MYC probe and its complementary DNA target, noncomplementary (NC) or mismatched DNA sequence (MM), or and in the presence of mixture of DNA target: NC (1:1) and DNA target: MM (1:1).