Is this water safe to drink?

UBC researchers hope to patent a device to detect water-borne pathogens in real time – a technology that currently doesn’t exist, and one that could potentially help prevent human illness caused from dangerous organisms that can infiltrate treated water systems.

“Currently, plant operators can’t actually detect a pathogen in water on location at treatment facilities,” says Debbie Roberts, principal co-investigator and Associate Director of the School of Engineering at UBC’s Okanagan campus. “They send samples away to labs for testing, and quite often that doesn’t happen until after people have started to get sick.

“The fact is, if I wanted to find out what is in my water to determine at that very moment if it is safe to drink, I couldn’t do it. So I want to develop the technology that can.”

The device is a portable, box-like system called a capture cell that passes a stream of treated water over a series of plates that contain capture molecules, such as antibodies. The capture molecules have an ability to bind to pathogens present in the water.

Once the sample is collected, the plates are removed and dipped into a solution that contains signal molecules – known as micro retro-reflectors – that also contain an antibody. The result is an organism between two molecules, one of which has a reflector on it. This is then put into a detector and light is shone on it. If any light bounces back, the sample contains a pathogen. If no light bounces back, it is a clean sample.

The micro retro-reflector technology was developed by colleagues of Roberts at the University of Houston, although they didn’t have

a practical application for it at the time.

“The technology was really all there, it just needed to be brought together. The biggest challenge was developing the actual capture device or sample cell,” says Roberts.

Mina Hoorfar, Assistant Professor of Engineering at UBC’s Okanagan campus and co-investigator in the project, was able to use her knowledge in fluid mechanics to put the last piece in the puzzle.

“And now,” says Roberts, “we are confident we have a prototype that will help us show proof of concept, so we can secure funding and move the project forward.”

Roberts expects the capture cell will have important practical applications for developing countries, as well as developed countries. With this in mind, researchers are working to make the capture cell a fairly inexpensive portable device with reusable pieces. Potentially, it could function as a water-quality detection device after a natural disaster such as an earthquake or tsunami.

To make the detection system a practical tool for developing countries, some tweaking is necessary to address concerns related to temperature stability and potential lack of power sources. However, Roberts believes once the basic concept is proven, the device can be manipulated to serve

a number of objectives.

“For example, take the earthquake in Haiti,” says Roberts. “This device could determine fairly quickly, in real time, what water sources contain the least amount of pathogens, or hopefully be clean and thus suitable for drinking with the least amount of treatment.”

And although the prototype focuses specifically on detecting the microscopic water-borne parasite Cryptosporidium, the capture cell could eventually contain an array of plates and capture molecules that are able to detect any organism, or even chemical, for which a capture molecule exists.

“We are working to detect Cryptosporidium right now because it is a well-known pathogen that has a history of causing sickness in communities, and because there is a current technology using these antibodies, so we know they are commercially available and accepted by regulatory agencies,” says Roberts.