Chemist Juewen Liu is developing a new test to detect pathogens and contaminants in water

Wednesday, April 5, 2017

Juewen Liu will receive more than $100,000 over three years from the Ontario Ministry of Environment and Climate Change for research initiatives that test pathogens and chemical contaminants in water.

Liu and his team are developing DNA-based sensors to detect contaminants, particularly heavy metal ions, in water. Heavy metal contamination of water is of significant environmental and health concern, as these metals are bioaccumulative and highly toxic, especially to children. For the general population, drinking water is a main source of potential heavy metal intake.

Liu working in his lab to detect water contaminants.

Liu’s project aims to search for new DNA sequences that can selectively detect cadmium and mercury using DNAzyme technology. DNAzymes are DNA-based catalyst molecules. The heavy metal ions will activate a cleavage event in the DNAzymes, and such cleavage events will be converted to fluorescent signals.

“We aim to achieve low parts-per-billions or even lower detection limits for these two metals to meet the US Environmental Protection Agency (EPA) or World Health Organization (WHO) regulations.”

By complementing the current instrumentation–based detection and quantification of heavy metals in environmental water samples, biosensors are attractive for their cost-effectiveness and on-site and real-time detection capabilities. The team will use samples from a variety of sources such as Lake Ontario water, Grand River water and city tap water in this project.

This research is highly relevant to Ontario’s current and future environmental needs since it may provide a cost-saving new technology to address contamination problems from a very important class of contaminants.