Researchers develop nanocoating that kills bacteria on contact

A team of researchers from the Institute of Bioengineering and Nanotechnology (IBN) have created a nanocoating that can spontaneously kill bacteria upon contact.

The team, led by Dr Yugen Zhang, were inspired by the wings dragonflies and cicadas which contain nanopillars that prevent bacterial growth. The natural structure of the wings means that when bacteria comes into contact with them, their cell membranes get ripped apart, immediately killing them.

The technology is intended to be particularly useful in hospital settings where sterilisation is important to help control the spread of infections.

To create the nanocoating, the researchers grew nanopilllars of zinc oxide, a compound known for its anti-bacterial and non-toxic properties. The zinc oxide nanopillars can kill a broad range of germs like E. coli and S. aureus that are commonly transmitted from surface contact.

Tests on various surfaces showed that the coating effectively killed up to 99.9% of germs. More so, because the bacteria are killed mechanically rather than chemically, the use of the nanocoating would not contribute to environmental pollution. Bacterial will also not be able develop resistance as they are completely destroyed when their cell walls are pierced by the nanopillars.

IBN executive director Professor Jackie Y. Ying, said: “There is an urgent need for a better way to disinfect surfaces without causing bacterial resistance or harm to the environment. This will help us to prevent the transmission of infectious diseases from contact with surfaces.”

Further studies showed that the nanocoating proved to work best on zinc surfaces, due to how the nanopillars catalysed the release of superoxides which could even kill nearby free-floating bacteria that were not in direct contact with the surface.

Dr Zhang said: “Our nano coating is designed to disinfect surfaces in a novel yet practical way. This study demonstrated that our coating can effectively kill germs on different types of surfaces, and also in water. We were also able to achieve super bacteria killing power when the coating was used on zinc surfaces because of its dual mechanism of action. We hope to use this technology to create bacteria-free surfaces in a safe, inexpensive and effective manner, especially in places where germs tend to accumulate.”

The study was recently published in the journal Small. IBN has recently received a grant from the National Research Foundation to further develop the coating technology over the next five years.