Esther Ng Today Online 20 Mar 12;
SINGAPORE - An hour, instead of seven, is all it takes to detect bacteria in treated water with a device developed by a Nanyang Technological University (NTU) researcher, and it could prove to be a boon for countries fighting water-borne diseases.
Professor Liu Ai Qun's Parasitometer works by directing water through a tiny channel - about the width of a human hair - within a small chip and shining a laser though the treated water.
Microscopic contaminants like E.coli can be detected from the way laser bounces off the matter and through it.
Said Prof Liu: "We are able to identify cells by knowing their cell shape, the diameter and size, as well as their refractive index - how well they reflect light and let light through."
This is done with a camera sensor that captures the light refraction data.
In the case of testing for Cryptosporidium, which can cause diarrhoea in humans if present in drinking water, using the Parasitometer takes up only one-eighth the cost of the current industry-standard test.
It can also pick up a single such cell - four-hundredths the width of human hair - from a 10-litre sample in one hour, compared with seven days with the standard test, or up to two days for detecting E.coli.
The project, which ran for three years, received S$1.77 million in funding from the PUB's Environment and Water Industry Programme Office and was supported by the Singapore National Research Foundation.
The PUB plans to use this technology to test treated water at its labs - it currently uses another method - before deciding whether to extend the application to its plants, its spokesperson said.
Commercialisation of the technology is expected to begin in June.
Prof Liu and the NTU have set up a company called Water Optics Technology, and is looking for S$2 million in funding from businesses and venture capitalists.
There has been "some commitment" from investors, Prof Liu said.
The global water monitoring market is estimated to be US$7.4 billion.
Though the current prototype weighs 50kg and measures 60cm by 50cm by 50cm, Prof Liu estimates the commercialised device will only be half the size and weight, and cost around S$15,000.
