Water nanostructures disinfect air


The EWNS can disinfect air but start off as nothing more than atmospheric water vapour

Engineered water nanostructures (EWNS), the latest weapons for tackling airborne pathogens, start off as nothing more than atmospheric water vapour.

Despite advances in antibiotics, vaccines and infection control, infectious diseases continue to affect hundreds of millions of people each year and the number of antibiotic resistant bacteria is on the rise. Therefore, there is an urgent need for innovative, effective and low-cost technologies in the battle against airborne infections. Upper-room UV irradiation, air filtration, photocatalysis and biocidal gases are the current methods most commonly used for air disinfection. However, these methods come with a variety of drawbacks such as potential health risks and high costs.

Philip Demokritou and colleagues from the Harvard School of Public Health and the National Institute of Occupational Safety and Health in the US, have designed a system that transforms atmospheric water vapour into EWNS. With a size of only 25nm, the nanostructures are highly mobile and remain in room air for a long time due to their high electric charge. Disinfection of the air is achieved as the nanostructures contain reactive oxygen species, such as hydroxyl and superoxide radicals, which interact with the outer membranes of bacteria, rendering them inactive.

Toxicological studies on mice by Demokritou’s team have shown that the EWNS have minimal toxicological effects. No respiratory tract toxicity was found at exposure levels and times higher and longer than those needed to inactivate the bacteria. Demokritou explains that the radicals are harmless to cell membranes in the lungs of test animals because ‘the organic matter in the lung lining fluid which covers the epithelial cells neutralises the reactive oxygen species, so they never reach the cells.’

‘The proposed method has the potential to transform the way we currently control infectious diseases,’ says Demokritou, ‘if proven effective in practice, it could be used to create “shields” to protect people in their microenvironments.’

Vishal Shah, an expert in microbiology from Dowling College in New York, US, agrees that the research presents ‘a proof-of-concept for an interesting technology that could help improve air quality, particularly in high moisture indoor environments.’ Shah adds that in the future, he would ‘look forward to seeing results describing the efficiency of the technology to inactivate other viruses and gram positive bacteria like streptococci and staphylococcus.’

The team now intend to extend their research to ascertain if EWNS can disinfect fresh produce.


Related Content

Clever comestibles

28 July 2011 Feature

news image

Controlling the microscopic structure of foods could make diet products that help you feel fuller for longer. Emma Davies get...

Chemists on a mission

21 February 2014 Feature

news image

The dramatic footage from a humanitarian crisis rarely features chemists, but they can play a vital role. Fiona Case is inspi...

Most Read

Better batteries with pure lithium anodes

28 July 2014 Research

news image

Protective carbon nanosphere coating overcomes lithium problems, pointing the way to improved capacity

Takeover battle pushes Allergan to cut R&D jobs

28 July 2014 Business

news image

Besieged by serially acquisitive Valeant, the Botox maker will lay off 1500 staff to propel earnings growth

Most Commented

Bubble wrap could send lab costs packing

23 July 2014 Research

news image

Potential bubbles up across wide range of uses as storage and test vessels, especially for poor countries

Relativity behind mercury's liquidity

21 June 2013 Research

news image

First evidence that relativistic effects are indeed responsible for mercury's low melting point