Reach 2025: Water, Water Everywhere
By Ty Burke
Illustration by Cornelia Li
CIFAR quantum researchers want to put water testing technologies in the palm of your hand.
Clean drinking water is a basic necessity. Yet, according to the World Bank, nearly 2 billion people around the world don't have access to reliably clean drinking water. Each year, 3.5 million people die from water-borne diseases like dysentery and cholera. Contaminants like plastics, arsenic and hazardous chemicals can contribute to long-term health problems like cancer.
Researchers in CIFAR’s Quantum Information Science program want to change this. They're developing hand-held quantum sensors to identify contaminants in water to help people identify risks before it's too late.
Ajoy is collaborating with Christine Muschik of the University of Waterloo’s Institute for Quantum Computing to develop a nuclear magnetic resonance spectroscopy device. It's capable of identifying trace amounts of contaminants by measuring their effect on the spin of electrons. In this device, infinitesimally small droplets of water are embedded in a drop of oil and circulated through a tiny channel at high speed. The liquid flows past a sensor made of nanoparticles of diamond.
And their magic is in their defects, called nitrogen vacancy centres. These centres fluoresce – or light up – when exposed to magnetism.
“These defects are what make a diamond pink,” says Ajoy. “And if you shine green light on them, they fluoresce red. This fluorescence is property of the spin of the electron in the defect centre. The amount of fluorescence is a function of the electron’s spin, and can be measured with very high precision.”
This paves the way to identifying specific contaminants like plastics or agricultural chemicals based on their unique magnetic signature. And Ajoy and Muschik’s device is highly sensitive – able to detect levels of magnetism just one-millionth the strength of Earth’s magnetic field.
The device that Ajoy and Muschik are developing promises precision and portability, and would be a dramatic improvement on the technologies currently used to identify contaminants. One such machine is the mass spectrometer, a kind of atomic scale that has been around for decades.
Mass spectrometry can detect vanishingly small quantities of a material by measuring atomic weights. But these devices can be as large as a room and cost millions of dollars. There is no way to take one to a rural village well, or a disaster zone where the water supply has been compromised.
“In principle, the device could be made very small, and the costs are low too,” says Ajoy. “People often think it is expensive because it uses diamonds, but the diamonds we use are very cheap. In one recent experiment, the diamonds in the device cost less than the oil we used. And the laser could be a low-cost diode. There is nothing fancy in this device, and the entire thing could be made at a relatively low cost.”
Like many other quantum sensing technologies, nuclear magnetic resonance technology is more evolutionary than revolutionary. Quantum sensors can be more sensitive, cheaper or portable, unlocking new applications and putting the technology in the hands of people who don’t currently have access to them.
Ajoy credits the flexibility of CIFAR funding with advancing this research. It allowed him to attend molecular sensing conferences that deepened his understanding of droplet technology. And CIFAR’s twice-annual Quantum Information Science program meetings connected Ajoy with leading researchers like Muschik, who brought a theoretical lens to the work.
Related Articles
-
CIFAR launches new exploration on “The Future of Food”
July 15, 2025
-
CIFAR Distinguished Fellow W. Ford Doolittle appointed Companion of the Order of Canada
July 08, 2025
-
New and returning AI talent at CIFAR
July 03, 2025
-
In Memoriam: Raymond Laflamme
June 24, 2025