Objective: In the present study copper oxide (CuO) nanoparticles were synthesized and characterized. The antibacterial activity of CuO nanoparticles was carried out against Escherichia coli, Proteus vulgaris, Staphylococcus aureus and Streptococcus mutans. Methods:The synthesis was carried out by coprecipitation method using copper sulfate and sodium hydroxide as precursors. The synthesized copper oxide nanoparticles were characterized by using X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), UV-vis spectroscopy and scanning electron microscope (SEM) with Dept of Physics, acharya Nagarjuna University, NH16, Nagarjuna Nagar, Guntur, Andhra Pradesh 522510 Email: peddikiranmayi@gmail.comEnergy Dispersive X-ray Analysis (EDX) techniques. Besides, this study determines the antibacterial activity and minimum inhibitory concentration (MIC) of CuO nanoparticles against gram-positive (Staphylococcus aureus and Streptococcus mutans) and gram-negative (E. coli and Proteus vulgaris) bacteria. Results:The average crystallite size of CuO nanoparticles was found to be 19 nm by X-ray diffraction. FT-IR spectrum exhibited vibrational modes at 432 cm -1 , 511 cm -1 and 611 cm -1 Keywords: CuO nanoparticles, XRD, FTIR, SEM, EDS, Antibacterial activity were assigned for Cu-O stretching vibration. According to UV-Vis spectrum, two bands were observed at 402 nm and 422 nm. ED's spectrum shows only elemental copper (Cu) and oxide (O) and no other elemental impurity was observed. The antimicrobial assay revealed that Proteus vulgaris showed a maximum zone of inhibition (37 mm) at 50 mg/ml concentration of CuO nanoparticles. Conclusion:In conclusion, copper oxide is a good antibacterial agent against both gram positive and gram-negative organisms.

Objective: In the present study the antibacterial activity of zinc oxide (ZnO) nanoparticles was investigated against gram negative (Escherichia coli and Proteus vulgaris) and gram positive (Staphylococcus aureus and Streptococcus mutans) organisms.Methods: The synthesis of ZnO nanoparticles was carried out by co-precipitation method using zinc sulfate and sodium hydroxide as precursors. These nanoparticles were characterized by XRD (X-Ray Diffraction), FTIR (Fourier Transform Infrared Radiation), UV-Visible spectroscopy and SEM (Scanning Electron Microscope) with EDX (Energy Dispersive X-ray analysis). As well as antibacterial activity and minimum inhibitory concentration of the nanoparticles were carried out by agar well diffusion method and broth dilution method respectively against gram negative (Escherichia coli and Proteus vulgaris) and gram positive (Staphylococcus aureus and Streptococcus mutans) bacteria.Results: The average crystallite size of ZnO nanoparticles was found to be 35 nm by X-ray diffraction. The vibration bands at 450 and 603 cm-1 which were assigned for ZnO stretching vibration were observed in FTIR spectrum. The optical absorption band at 383 nm was obtained from UV-Visible spectrum. Spherical shape morphology was observed in SEM studies. The antibacterial assay clearly expressed that E. coli showed a maximum zone of inhibition (32±0.20 mm) followed by Proteus vulgaris (30±0.45 nm) at 50 mg/ml concentration of ZnO nanoparticles.Conclusion: Zinc oxide nanoparticles have exhibited good antibacterial activity with gram negative bacteria when compared to gram positive bacteria.

Objective: In the present study, synthesized alumina (Al2O3) Methods:The synthesis was carried out by coprecipitation method using aluminium sulfate and NaOH as precursors. The synthesized aluminium oxide nanoparticles were characterized by using X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) with nanoparticles were characterized and their antibacterial activity against gram positive and gram negative organisms were studied.Energy Dispersive X-ray Analysis (EDX) techniques. Besides, this study determines the antibacterial activity and minimum inhibitory concentration (MIC) of Al2O3Results: The average crystallite size of Al nanoparticles against gram-positive (Staphylococcus aureus and Streptococcus mutans) and gram-negative (E. coli and Proteus vulgaris) bacteria.2 O3 nanoparticles was found to be 35 nm by X-ray diffraction. FT-IR spectrum exhibited the peaks at 615 and 636 were assigned to the aluminium oxide stretching. The EDX measurements indicated the presence of Al along with O peaks. It indicates the purity of the sample. The antimicrobial assay revealed that E. coli showed a maximum zone of inhibition (39 mm) at 50 mg/ml concentration of Al2O3 Conclusion:In conclusion, aluminium oxide is a good antibacterial agent against both gram positive and gram-negative organisms.nanoparticles.