

ROURKELA: A team of researchers from the National Institute of Technology-Rourkela (NIT-R) has developed a safe and natural solution to fight drug-resistant bacteria using plant extracts.
The team, led by associate professor of Department of Life Science Suman Jha, along with research scholars Kumari Subham, Sonali Jena and Monalisha Ojha, used extracts from marigold, mango and eucalyptus to create a ‘herbal shield’ containing natural zinc oxide nanoparticles.
These nanoparticles enhance antibacterial action without relying on toxic chemicals. Remarkably, marigold-derived nanoparticles were found to be twice as effective as chemically-synthesised ones.
The overuse of antibiotics has led to the rise of ‘superbugs’, prompting global efforts to find alternative treatments. One promising approach involves zinc oxide nanoparticles, which attack bacterial cells, disrupting their functions and killing them. Electrically charged zinc ions damage bacterial cell membranes, produce reactive molecules that stress the bacteria, and block essential cellular processes. Conventional methods for synthesising these nanoparticles, however, use harsh chemicals that can be toxic to humans and the environment.
To address the challenge, the researchers used leaf and petal extracts to reduce zinc salts into zinc oxide nanocrystals with adsorbed phytocompounds from the extracts. The research stated that the natural plant extracts not only aid in nanoparticle synthesis but also stabilise them by forming a herbal shield or phytocorona.

This shield controls the release of zinc ions, ensuring steady antibacterial action. In addition, plant compounds such as flavonoids, alkaloids, tannins and phenolics provide a ‘double attack’ on bacterial cells.
“Our vision is to develop scalable, affordable, and environmentally-safe antimicrobial materials that can be integrated into healthcare, sanitation and food preservation applications. By harnessing India’s rich biodiversity and indigenous plant resources, we aim to create self-reliant innovations that contribute meaningfully to global health and sustainability goals,” Jha said.
The research findings have been published in the prestigious ‘Surfaces and Interphases’ journal.