A personal bioaerosol sampler for Canada’s armed forces
“It’s exciting to see our aerosol collection technology gaining the international recognition it deserves. This collaboration with Dstl and our Canadian partners is a unique opportunity to rigorously test the technology, push its capabilities to the limit, and explore new applications and avenues for further development.”
Loic Coudron
Professor of Digital Microfluidics and Aerosol Detection, University of Hertfordshire.
What advances are we aiming for?
DRDC and the NRC have developed a handheld electrochemical biosensor that has the potential to classify pathogens, including those causing emerging diseases, in near real time with a low false alarm rate. They are exploring its integration with a novel bioaerosol collection system developed at UH under contract with Dstl.
UH’s miniaturised system leverages electrostatic precipitation and electrowetting on dielectric (ESP-EWOD) technologies. The ESP air sampler creates an electric field to attract particles onto a hydrophobic surface, separating them from the surrounding air. The sample is placed in a digital microfluidic liquid handling system, also developed at UH in contract with Dstl, which uses an electrowetting process to manipulate microscale liquid droplets and elute the collected particles into a liquid medium for further analysis. This automated process minimises the need for user training, as operators do not require proficiency in handling filters for sample extraction, elution and concentration.
We are evaluating the performance of the ESP-EWOD system, comparing it with commonly used air samplers, and exploring how the collected samples can seamlessly integrate with DRDC’s biosensor for accurate, near-real-time analysis.
What have we achieved so far?
Initial trials involving three types of bacteria in a controlled bioaerosol chamber have shown that the ESP-EWOD device is a promising technology for integration within a fully automated bioaerosol detector system.
Results showed that ESP-EWOD has comparable collection and elution efficiency to standard collection systems for two of the bacteria, but reduced elution efficiency for the other. Even then, ESP-EWOD outperformed the standard techniques in providing highly concentrated samples, with a sample concentration 1,000 times higher for E. coli and P. agglomerans, and 33 times higher for B. atrophaeus spores. This is a significant result as a highly concentrated sample increases the likelihood of detection and is key to faster, more accurate analysis.
Where next, through the Hub?
The consortium is conducting further field testing, comparing traditional equipment with the novel detection system that integrates UH’s collection technology with the electrochemical biosensor. While final results are pending, preliminary on-site analysis indicates high levels of performance.
Future plans for the technology include additional field trials in complex environments, such as animal barns or wastewater treatment plants. DRDC is also evaluating the integration of the technology on uncrewed aerial vehicles for remote sensing applications.
