Green Synthesis Of Zno & Cu Doped Zno Nanoparticles Using Leaf Extract Of Azadirachta Indica:Its Application On The Drug Resistant Bacteria

Abstract

The progress of green chemistry in the synthesis of nanoparticles using plants has attracted a great attention due to its low cost and non-toxic and environment-friendly nature. The present study focuses on the biological synthesis and characterization of pure and Cu-doped zinc oxide nanoparticles using different ratios of neem leaf extract and the nanoparticles for antibacterial application on the drug resistant bacteria. Zinc Nitrate hexahydrate and zinc acetate dihydrate were used as precursor to synthesize ZnO nanoparticles whereas zinc acetate dihydrate and copper nitrate trihydrate were used to synthesize Cu-doped ZnO nanoparticles. The synthesized nanoparticles were characterized by advanced techniques like Thermo Gravimetric Analysis (TGA), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive XRay Spectroscopy (EDX), Fourier Transform Infrared Spectroscopy (FT-IR), and UV-Visible spectroscopy. TGA was performed to study the thermal stability of pure & Cu doped ZnO nanoparticles and the results showed that the synthesized materials were stable above 400⁰C. The desired phase formation and crystal structure of the synthesized materials were followed by X – Ray Diffraction (XRD) analysis. The XRD analysis revealed that all the synthesized particles have pure hexagonal phase with particle size in the range of 16 – 24 nm. The SEM analysis indicated the spherical shape morphology for the samples that were calcinated at 400 0C and their grain size increased with the decrease of the concentration of the capping agents or leave extract. EDX spectra showed the elemental composition of the synthesized nanoparticles. The FT-IR technique has been used to study the interaction between the capping agents and the synthesized ZnO nanoparticle which was also confirmed by SEM studies. The UV-Visible investigation also confirmed the formation nanoparticle, the absorbance peak at 376 nm corresponding to the characteristic band of zinc oxide nanoparticles. The antibacterial activity studies of the synthesized materials against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Proteus mirabilis have better performance with the reference to the selected standards gentamicin and ciprofloxacin.