Preparation of an electrochemical biosensor for the study of DNA interaction with Flutamide using hemin

Flutamide is the first discovered compound that meets the criteria of a pure antiandrogen[1]. It is of particular interest to investigate the effect of this drug on the DNA structure as it is widely used for the treatment of prostate cancer nowadays [2, 3]. Development of DNA biosensors for the understanding of DNA interactions with molecules has been raised in recent years [4]. An improved performance for DNA biosensors could be achieved by modifying the electrode surface using different nano materials which lead to an increase in electrochemical signal. One of these candidates is mesoporous silica material that showed good aspect for surface modification in fabrication of DNA biosensors. MCM which was discovered in 1992 [5, 6] is a promising candidate for the immobilization of various bio and nano materials and can be used to develop stable biosensing systems owing to their unique properties such as high surface area, porosity, uniform pore size distributions, thermal stability and also the high stickness stability after immobilization on the electrode surface which lead to a stable and steady response. In this study, the electrochemical biosensor was prepared by modifying screen-printed graphite electrode (SPE) with mesoporous structure of MCM41 to immobilize DNA structure. The mesoporous structure introduces a significant surface area and can increase the amount of adsorbed DNA on the surface. The interaction of Flu as the anticancer drug with ssDNA and dsDNA was studied in Tris-HCl buffer and also in the presence of Hemin (HEM) as a suitable electroactive redox label. The differential pulse voltammetry (DPV) current of HEM reduction peak decreases with the increasing concentrations of drug due to the interaction of DNA/Flu. The peak current of HEM linearly decreased with the 13th Annual Electrochemistry Seminar of Iran Materials and Energy Research Center (MERC), 22- 23 Nov, 2017 89 concentration of Flu in the range 0.7 to 10 M (R2 = 0.9907), with a detection limit of 0.1 M.