Plant Mixture Mediated Biogenic Copper Nanoparticles: Antibacterial Assay

Synthesis of nanoparticles is an extensive area for the scientists and plant-mediated biological synthesis is one of the green approaches attracted to the researchers. Objective: This experiment revealed the biological synthesis of copper nanoparticles (CuNPs) using aqueous extract mixture of two plants named bark extract of Moringa pterygo sperma (Sargavo) and root extract of Boerhavia diffusa (Saatodi/Punarnava). Method: Biomolecules present in the plants act as a reducing agent as well as a capping agent. In this reduction reaction, copper (II) metal reduced by biomolecules present in plants leads to the formation of CuNPs. Biosynthesized CuNPs characterized by spectral analysis (XRD, FTIR, UVvisible) and imaging microscopy (FEG-SEM with EDS and HR-TEM). Results: X-ray Diffraction spectroscopy revealed that crystalline CuNPs possess face centred cubic structure with an average size 2.20 nm. Fourier Transmission Infra-red spectroscopy showed that biomolecules like proteins are responsible for the reduction of metal ion and forming encapsulating layer on the metal ions (capping of CuNPs). Morphology of the CuNPs studied using Field Electron Gun Scanning Electron Microscopy (FEGSEM) and showed an irregular spherical shape. Elemental composition and purity of the CuNPs were analysed by Energy Dispersive Spectroscopy (EDS). High- Resolution Transmission Electron Microscopy revealed that the size of the CuNPs was 2 to10 nm. Antibacterial study of the biosynthesized CuNPs was examined against gram-positive (Bacillus subtilis) and gram-negative (Escherichia coli) bacteria using agar well diffusion method and CuNPs exhibited an excellent inhibition zone against the mentioned bacteria.