Green synthesis of copper oxide nanoparticles using christia vespertilionis aerial parts extract: A sustainable approach for antibacterial efficacy assessment

Abstract

Metal nanoparticles typically exhibit sizes ranging from 1 to 100 nanometers and can be produced by several techniques, such as green synthesis and chemical synthesis. This study focuses on the green synthesis of copper oxide nanoparticles (CuO-NPs) using aerial extract of Christia vespertilionis. The observation of CuO-NPs formation was made based on the variations in colour exhibited by the extract mixture following the introduction of copper (II) sulphate (CuSO4). The synthesised nanoparticles underwent characterization utilising various instrumentation techniques, including UV-Vis spectrophotometry, FTIR, TEM, SEM, EDX, and TGA. The antibacterial activity of these nanoparticles was assessed by using disc diffusion method, against selected Gram-positive and Gram-negative bacteria. The investigation also encompassed an examination of the combined effect of the nanoparticles and the antibiotic Ciprofloxacin on antibacterial activity. In this study, it was noted that the maximum absorbance of the CuO-NPs occurred at a wavelength of 253nm. The functional groups of the CuO-NPs were confirmed through FTIR spectrum. TEM analysis revealed the average particle size of the CuO-NPs as 62.16 nm. Additionally, examination of SEM images revealed that the particles exhibited irregular shapes while maintaining a homogeneous distribution. The nanoparticles exhibited enhanced antibacterial efficacy against Gram-positive bacteria in comparison to the Gram-negative bacteria that were examined. Significant synergistic effect was shown when the CuoNPs were used with the antibiotic against the bacteria tested. In conclusion, the study conducted demonstrates favourable outcomes as an antibacterial agent and recommended to conduct additional research to investigate the mechanism of action and toxicity of this agent.