Due to the wide range of applications, the green synthesis of nanoparticles has received considerable attention in recent years. Apart from their low cost and ease of preparation, metal oxide nanoparticles derived from plant extracts exhibit good prospect. Green nanoparticles enable the elimination of highly toxic compounds and the production of sustainable, environmentally friendly products. Nanoparticles are widely used in the medical field as an antimicrobial agent due to their unique properties at the nanoscale scale. Zinc oxide nanoparticles (ZnONPs) synthesized from agricultural waste have demonstrated remarkable antibacterial and photocatalytic properties due to their small particle sizes and high surface reactivity.

This study demonstrates a rapid green synthesis approach for the production of ZnONPs using Malaysian agricultural extracts such as oil palm leaf, roselle flower, lemongrass, and turmeric. ZnONPs with sizes ranging from 10-15 nm have been synthesised successfully and found to be spherical in shape. FTIR was used to determine the functional groups of biomolecules involved in the formation of ZnONPs. The UV-Vis spectra at 375 nm revealed a distinctive absorption peak, the ZnO intrinsic band-gap absorption. Green ZnONPs are attracted to environmental applications due to their strong and stable photocatalytic performance, particularly in the reduction of organic pollutants in wastewater. ZnONPs are critical as photocatalyst materials.

Photocatalysis is a promising wastewater treatment technology, particularly for those containing difficult-to-remove organic compounds. The results indicate that ZnONPs were successfully synthesised using an aqueous agricultural extract and demonstrated significant photocatalytic activity in the reduction of a synthetic dye of interest. Prior to its application as a photocatalyst, the aquatic model organism brine shrimp (Artemia Salina L) was used to assess nanotoxicity.

Our green synthesised ZnONPs were found to be safe and biocompatible. Using the disc diffusion method, ZnONPs demonstrated significant antimicrobial activity against gram-negative bacteria (Escherichia coli) and gram-positive bacteria (Staphylococcus aureus). The current approach implies that by cultivating a green chemistry process for large-scale production, low-cost, waste-to-wealth, and rapid synthesis of ZnONPs are feasible.

The research is unique in that it makes use of a variety of domestic waste materials. This is consistent with UPM's mission to be the leading institution of higher education and agricultural research. Currently, many material scientists are concentrating their efforts on green nanotechnology, which involves the use of environmentally friendly and non-toxic nanomaterials in environmental and health applications. Green nanomaterials also help agriculture sector reduce the cost of fertilization and greenhouse gas emissions.

Assoc. Prof. Dr. Che Azurahanim Che Abdullah and her student, Lau Gee Een, are conducting research on the development of metal oxide nanoparticles using local agricultural waste in collaboration with researchers from the Faculty of Health and Medical Science UPM and the School of Biomedical USM. The current approach suggests that developing a green chemistry process for mass scale production could result in low costs, waste to wealth, and rapid synthesis of ZnONPs.

The Kurita Water Environmental Fund (KWEF) in Japan selected and funded this project for environmental applications, specifically ZnONPs as a water purification agent. Additionally, this project received a gold award in a few innovation competitions (INIIC 2019, WIAC 2020, and VIDE 2020). The green synthesis of nanomaterials through use of plants is a significant branch of nanotechnology. It has grown in popularity and importance as a result of its environmental friendliness, low cost, biocompatibility, and lack of toxic chemicals. This enables nanomaterials to have a positive impact on modern agriculture, which emphasises human health and the environment in addition to food and nutritional security.

For further information, please contact:
Assoc. Prof. Dr Che Azurahanim Che Abdullah
azurahanim@upm.edu.my

Date of Input: 03/09/2021 | Updated: 06/10/2021 | roslina_ar