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.