Green Synthesis of Bismuth Oxide Nanoparticles and Its In Vitro Antimicrobial Study Using Red River Gum (Eucalyptus camaldulensis) Leaf

Abstract

Nanotechnology has been stated as research and development at the atomic, molecular or macromolecular 
scales. Nanoparticles are considered to be the building blocks for nanotechnology, and are referred to 
particles with at least 1 to 100 nm dimension. The green synthesis of Bi2O3 nanoparticles was demonstrated 
in this work by employing an extract from Red River Gum (Eucalyptus camaldulensis) leaf as a reducing 
agent. The existence of bioactive chemicals, which were essential to the formation of Bi2O3 nanoparticles, 
was discovered by phytochemical analysis of the leaf extract. FTIR confirms the presence of Bi-O bond at 
1043.65459 cm-1, SEM revealed the morphological characteristics of the synthesized Bi2O3 nanoparticles, 
displaying the presence of some crystalline substances within an amorphous, XRD shows that, the 
synthesized Bi2O3 nanoparticles is in an amorphous state, and UV-Vis spectroscopy the excitation of 
electrons of Bi2O3 nanoparticles from the valence band to the conduction band was responsible for the 
absorption peaks at 480 nm and 580 nm, with a band gap energy of 2.58eV and 2.13eV respectively were 
used to characterized the synthesized Bi2O3 nanoparticles, and confirmed their synthesis. Bi2O3 
nanoparticles and red river gum leaf extract showed antimicrobial activity against gram positives 
staphylococcus epidermis and staphylococcus aureus and gram negatives pseudomonas aeruginosa, and 
escherichia coli bacteria, Bi2O3 nanoparticles were more effective, and both exhibited increased activity 
with higher concentration. This study demonstrates the potential of extract’s from red river gum (Eucalyptus 
camaldulensis) leaf assistance in green synthesis of Bi2O3 nanoparticles.