Green synthesis of copper oxide nanoparticles using Carica papaya and their antimicrobial activity

Abstract

In the field of nanotechnology, copper oxide nanoparticles (CuO NPs) are regarded as one of the most significant transition metal oxides due to their fascinating properties. Various methods such as the sol–gel method, chemical vapour deposition, spray pyrolysis, etc are available for the synthesis of copper oxide nanoparticles. Among these, the eco-friendly green synthesis method was used to prepare copper oxide nanoparticles. Green synthesis is the process of preparing nanoparticles using plant materials, microorganisms and various biowastes. However, this method aids an eco-friendly, simple and cost-efficient method to synthesise nanoparticles. Owing to their antimicrobial properties, CuO NPs are widely used in the field of medical textiles. The current study proposes a method for environmentally acceptable CuO nanoparticle synthesis employing a non-toxic, eco-friendly Carica Papayaleaf extract. The component of Papain present in the Carica papaya leaves is responsible for the greater antimicrobial activity. X-ray Diffraction (XRD) studies reveal the crystalline nature of the CuO NPs. Fourier Transform Infrared (FTIR) spectrum confirms the presence of copper bonds. Scanning Electron Microscopy (SEM) image shows that the synthesized NPs are spherical in shape and agglomerated due to the absence of a capping agent. Antimicrobial activity was tested against Escherichia coli and Staphylococcus aureus.Prepared CuO NPs nanoparticle coated on medical fabrics like gauze, facemask and gloves test for their zone of inhibition on three significant materials. It was found that the E. coli bacterium shows an increased rate of inhibition and provides better antimicrobial activity than S. aureus.