Green Synthesis of Nickel Oxide Nanoparticles using Populus ciliata Leaves Extract and their Potential Antibacterial Applications

Muhammad Hafeez,Sirajul Haq,Zain- Ul-Abdin,Muhammad Abdullah Khan,Bilal Akram,Salah Ud Din,Ruzma Shaheen,Maryum Zeb,Muhammad Naeem Ahmed

doi:10.17159/0379-4350/2021/v75a21

Abstract

ABSTRACT Green synthesis of nanoparticles has received a lot of attention from scientists globally because it is eco-friendly, relatively rapid, and a cost-effective method. This work presents a method for the green synthesis of nickel oxide nanoparticles (NiO-NPs) using leaf extracts of Populus ciliata as a reducing and stabilising agent. The synthesised NiO-NPs were characterised by ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. It was found that the synthesised NiO-NPs shapes varied, were highly crystalline, and had a face-centred cubic geometry. The calculated crystallite size of the synthesised nanoparticles was 44 nm. Moreover, the antibacterial activity of the synthesised NiO-NPs was also conducted against Gram-positive bacteria (Bacillus subtilis, Bacillus licheniformis) and Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae). Bacillus subtillus showed a maximum inhibition zone of 28.1±1.6 mm, whereas Klebsiella pneumonia showed a minimum inhibition zone of 9.2±0.5 mm. It was also found that the antibacterial activity increased with an increase in the concentration of NiO-NPs. Keywords: antibacterial activity, green synthesis, nanoparticles, NiO, Populus ciliata.

Highlights

IntroductionThe synthesis or fabrication of metal oxide nanoparticles (NPs) has received a great amount of attention from scientists globally.[1,2] These NPs bear unique properties (e.g. biological, mechanical, thermal, electrical, catalytic, and optical properties) compared to bulk materials with similar chemical compositions
The synthesis or fabrication of metal oxide nanoparticles (NPs) has received a great amount of attention from scientists globally.[1,2] These NPs bear unique properties compared to bulk materials with similar chemical compositions
It has been reported that the phytochemicals present in the extracts from the leaves are responsible for the reduction of metals ions into neutral metal atoms (Figure 2).[32]

Summary

Introduction

The synthesis or fabrication of metal oxide nanoparticles (NPs) has received a great amount of attention from scientists globally.[1,2] These NPs bear unique properties (e.g. biological, mechanical, thermal, electrical, catalytic, and optical properties) compared to bulk materials with similar chemical compositions. The toxic chemicals used during such synthetic procedures remain on the surface of NPs, and such NPs cannot be used for biomedical applications. Green synthesis can use bacteria, fungi or plant extracts to synthesise metal-based NPs.[12,13,14] Plant extract-based methods are usually low-cost and require less time to synthesise NPs. Green synthesis can use bacteria, fungi or plant extracts to synthesise metal-based NPs.[12,13,14] Plant extract-based methods are usually low-cost and require less time to synthesise NPs These methods usually involve one-step reaction procedures and are environmentally friendly. Such attributes make these methods the preferable choice for the synthesis of NPs.[15,16,17,18]

Methods

Results

Conclusion