Preparation of conducting nano composite electrodes and examination of availability in DNA base analysis

Chemically modified electrodes have been obtained by immobilization of various organic and inorganic modifiers on the electrode surface. Modified elctrodes are designed to aim for the improvement of stability, sensitivity and selectivity in analytical applications as voltammetric, amperometric and potantiometric sensors. In this work, electropolymeric nanocomposite electrodes have been prepared on glassy carbon electrode surface by using aniline, N-methylpyrrole, aniline-2-sulfonic acid monomers and gold nanoparticles with cyclic voltammetry. The electrocatalytic effect to guanine, adenine, dopamine and uric acid of prepared gold nanoparticle modified polyaniline, poly(N-methylpyrrole) and poly(aniline-2-sulfonic acid) composite electrodes has been investigated by DPV technique. Then, the parameters affecting sensor characteristics (polymeric film thickness, monomer, supporting electrolyte, gold nanoparticle concentration, film thickness of gold nanoparticles and pH) of electropolymeric nanocomposite electrodes were systematically optimized. The stability tests of the optimized sensors indicated that nano-Au/PA/GCE ve nano-Au/PNMPy/GCE are stable at 90 days, nano-Au/PASA/GCE is stable at 60 days. The base ratios in fish sperm DNA were determined by standart addition method. The ratio of G/A was calculated with 1,74% error for nano-Au/PA/GCE and 1,36% error for nano-Au/PASA/GCE