Project Lead(s): Stephanie Willerth
Unsafe water supplies represent one of the leading causes of death in developing countries.
Approximately 1.8 million deaths worldwide are a result of exposure to waterborne bacterial pathogens.
In developing countries, waterborne pathogen detection requires outsourcing samples to labs with expensive equipment, taking 2–6 weeks to obtain results.
The project sought to develop an affordable, long-term water quality detection device using microsphere-based technology.
The device consisted of three parts: lysozyme-releasing microspheres to lyse bacteria present in a water sample; microspheres that release DNA probes to detect contaminating bacteria; and a detector region consisting gold nanoparticles.
In the device, the detector region would change colour from blue to red if bacteria were present, providing an easy visual output indicating water quality.
Microspheres also allow for easy scale-up during the manufacturing and the system eliminates the need for an expensive detection system.
The successful development of a working prototype for affordable and stable water quality detection was the main accomplishment of the project.
This involved the development of three components:
1) Microspheres that can release DNA probes over time – polymer-based microspheres were used to encapsulate E. Coli DNA probes (hairpin probes) necessary for detecting E. Coli using a double emulsion process
2) Microspheres that can release bioactive lysozyme over time (up to 28 days) – confirmed cell lysis using the microspheres with E.coli and a lysis kit
3) The aggregation of gold nanoparticles in the presence of E. Coli DNA complexes was confirmed and demonstrated a concentration-dependent change in colour.
Laboratory analysis provided evidence of successful water quality detection.
Results were prepared for submission to a materials chemistry journal that focuses on sustainability.
The team also wrote a Natural Sciences and Engineering Research Council of Canada (NSERC) Idea to Innovation grant request to translate their prototype into a device suitable for mass manufacturing, by fine-tuning the concentrations of microspheres necessary for successful detection of bacteria, making the microsphere fabrication process more reproducible using microfluidics, and determining detection limits for the device.
Additional funding was received from the British Columbia Innovation Council.