In the present study, the synthesized aluminium oxide nanoparticles were characterized and their antibacterial activity against gram positive and gram negative organisms were studied. We  have used Combustion Synthesis technique for synthesis of Aluminium Oxide nanoparticle using Urea as an fuel and Aluminium Nitrate as an Oxidizer. This method is found to be easy & economical route & is able to produce Nano phase Alumina powder.  The synthesized aluminium oxide nanoparticles were characterized by using X-ray diffraction (XRD), This study also determines the antibacterial activity of

Al₂O₃nanoparticles against gram-positive (Staphylococcus aureus) and gram-negative (E. coli) bacteria.The average crystalline size of aluminium oxide nanoparticles was found to be 55 nm by

X-ray diffraction. Among the tested bacteria, 500 micro grams was found to be most resistant with a inhibition zone of 8.5 and 9.5 mm for Aluminium Nanoparticles against E. coli and S. aureus . Similarly 3 and 5.5 mm for Aluminium Nanoparticles at 250 µg/well against E. coli and S. aureus. The study clearly reveals that Aluminium Nanoparticles that can be used for topical application against bacteria.

Keywords: Al₂0₃ nanoparticles, Antibacterial activity, Fuel combustion synthesis, XRD.