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چکیده
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For the first time consecutive cyclic voltammetry was used to immobilization of Guanine oxidation products onto Zinc Oxide nanoparticles. Electrochemical studies have showen well known redox couple corresponding to 8-oxo-guanine/2-amino-1H-purine redox couple on the surface of ZnO nanoparticles. Further investigations indicated that zinc oxide nanoparticles prevent the guanine and 2 amino-1H-pirine from hydrolysis. The ab initio density functional theory (DFT) was used to examine the interaction of guanine oxidation products with the ZnO surfaces using a Zn3O3 cluster model. Geometry optimization, frequencies and adsorption energies for complexes, were calculated at the Density functional theory (DFT) method at the B3LYP/LANL2DZ level of theory. The theorical studies shows that the hydrolysis of 2-amino purine only take place only throw the 2-amino-6H-purine-6,8(9H)-dione and doesn’t take place throw its other tautomer ,” 2-amino-1H-purine-6,8-dione”. We found that 8-Oxo-Guanine and 2-amino-1H-purine-6,8-dione strongly adsorbed by ZnO nanoparticles. The interaction consists of the combination of a Zn-N bond between the Lewis acid Zn and the amine base from Guanine oxidation productes and additional Vander Waals interactions and H bonds. The result of the adsorbtion of guanine oxidation products is a fixed redox couple which prevent from hyrolysis by Zinc oxide.
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