Abstract

Luminescence-based sensors are widely used and are the subject of considerable attention from both a research and a commercial perspective. This work details the development of enhanced-performance luminescence-based sensor systems. Development eorts have focussed on three areas: instrumentation electronics, en- hanced luminescence capture-based optical platforms, and multi-parameter sens- ing using numerical techniques. Three instrumentation electronics systems were developed using a progressive design process that culminated in the development of a DSP-based system which is capable of multi-frequency operation and can be used to obtain intensity, phase or ratiometric-intensity measurements. When a luminophore is placed close to a dielectric interface it exhibits an anisotropic emission prole. An optical probe that exploits this phenomenon to achieve enhanced luminescence capture was designed previously, however, it suered from a number of shortcomings. A range of design improvements were developed and implemented which addressed a number of robustness and reliabil- ity related issues and which facilitated ratiometric mode operation. In addition, an enhanced capture element that was optimised for general sensing as opposed to bio-sensing applications was designed using a combined ray tracing/optimisation approach. The detection of multiple parameters using a single luminescent sensor ele- ment is desirable in many applications. A multi-parameter technique was devel- oped that achieves this through the use of numerical techniques. This approach addresses a number of limitations that are associated with alternative techniques. A key part of this work was the development of sensor systems for a number of specic applications. Sensor systems were developed for the following: real-time measurement of oxygen concentration in breath, measurement of dissolved oxygen and dissolved carbon dioxide, and the simultaneous measurement of oxygen and temperature using a single sensor element.