Grant: Discovery Grants Program - Individual

Conventional methods for monitoring organic compounds in contaminated sites rely on sample collection, transportation, storage, preparation and instrument analysis by gas chromatography (GC) or high performance liquid chromatography (HPLC). Although the conventional laboratory analysis provides high accuracy, sensitivity and selectivity, it is expensive, time-consuming and discontinuous. To address this issue, cavity enhanced fibre optic sensors will be developed for detection of organic contaminants. The proposed sensors are capable of real-time and on-site measurements. The short-term objective of the proposed research is to design, construct and characterize prototypes in the laboratory. The long-term objective will focus on miniaturization of the instrumentation, followed by on-site field measurements and remote site deployment. In the proposed optical fibre sensors, subtle optical attenuation will be detected using fibre-cavity ring-down spectroscopy (FCRDS), a sensitive absorption technique where the optical cavity can be formed by two dielectric coatings on both fibre ends or a simple fibre loop. The effective optical path length can be increased by two orders of magnitude in such a cavity configuration. Chemical sensing blocks will be introduced using a number of approaches. In summary, the proposed research will bring the laboratory to the samples rather than the samples to the laboratory. The proposed research will deliver new insight on the environmental impacts of organic contaminants and a new level of surveillance and safety that is required by commercial labs, decision makers and the public. Initial applications will focus on (i) air quality monitoring where the loss of sample during transport is problematic and (ii) drinking water monitoring where real-time data acquisition is critical.