University of Guelph
On-site diagnostic tools are an essential part of emergency management given that early detection of the hazard leads to rapid containment and corrective action. However, current diagnostic devices for on-site testing are lacking, expensive or require multiple step protocols and technical expertise. The proposed research will develop fluorescence optical sensors based on molecular imprinted polymers (MIPs) modified with quantum dots. MIPs are artificial antibodies that can be produced to have affinity for a diverse range of targets. Unlike antibodies, MIPs are stable, easy to produce and low cost. The proposed work will focus on the detection of viruses that could be potentially devastating to agriculture, in addition to dioxins- a stable toxic agent that can be readily acquired by the would-be terrorist. The sensors will be fabricated by polymerization of the polymer around a suitable template (structural analoge). Upon template removal, voids are left on the polymer surface with affinity towards the target analyte (virus or dioxin in the current study). To report the binding event of analyte with the imprints the decrease in fluorescence of quantum dots will be used. The quantum dots will be introduced into the polymer either pre- or post-polymerization. Imprinting polymers onto the surface of quantum dots will also be investigated. The optimized quantum dot:MIP combination will be introduced onto the walls of a microfluidic cell where non-specific binding will be controlled through inducing electroosmotic flow.The microfluidic system will permit larger volumes of sample to be processed, in addition, to reducing the number of steps required by the operator. The sensors will be optimized in terms of polymer fabrication and operating perameters of the microfluidic chip. Sensor performance will be verified through by detecting viruses in artificially infected plants and ability to detect dioxins in complex sample matrices (e.g. milk) At the end of the research will produce a sensor that could readily be incorporated into a handheld device and will provide a powerful tool for Federal agencies inspectors for screening food and environmental samples. In addition, the sensors should be affordable to use by producers and processors to routinely screen for potential chemical or biological hazards within food production systems.