An azo complex was prepared from the reaction of Zn(II) with the ligand 8- [(4-hydroxyphenyl) azo] guanine. A reaction with Zn(II) gave a new complex Bis(8- [(4-hydroxyphenyl) azo] guanine) zinc (II) chloride at pH = 8. Spectrophotometry of the prepared complex was performed using UV-Visible and infrared spectra and micro-elemental analysis. Zinc oxide nanoparticles were then prepared from the prepared complex by thermal decomposition method. The nano particles characteristic to know its structural properties was conducted by using a scanning electron microscope, atomic force microscopy and X-ray diffraction. The biological activity of the azo-zinc complex and the zinc oxide nanoparticles was studied against E. coli, Ps. aeruginosa and S. aureus. The iso-zinc oxide nanocomplex was more effective than the iso-zinc complex against these genera of bacteria.
Key words: ZnO , Nanoparticles , Complex , Biological , guanine