Development of enhanced performance luminescence-based optical sensor systems for single-analyte and multii-analyte applications

摘要

Luminescence-based sensors are widely used and are the subject of considerableudattention from both a research and a commercial perspective. This work detailsudthe development of enhanced-performance luminescence-based sensor systems.udDevelopment eorts have focussed on three areas: instrumentation electronics, en-udhanced luminescence capture-based optical platforms, and multi-parameter sens-uding using numerical techniques.udThree instrumentation electronics systems were developed using a progressiveuddesign process that culminated in the development of a DSP-based system whichudis capable of multi-frequency operation and can be used to obtain intensity, phaseudor ratiometric-intensity measurements.udWhen a luminophore is placed close to a dielectric interface it exhibits anudanisotropic emission prole. An optical probe that exploits this phenomenonudto achieve enhanced luminescence capture was designed previously, however, itudsuered from a number of shortcomings. A range of design improvements wereuddeveloped and implemented which addressed a number of robustness and reliabil-udity related issues and which facilitated ratiometric mode operation. In addition,udan enhanced capture element that was optimised for general sensing as opposed toudbio-sensing applications was designed using a combined ray tracing/optimisationudapproach.udThe detection of multiple parameters using a single luminescent sensor ele-udment is desirable in many applications. A multi-parameter technique was devel-udoped that achieves this through the use of numerical techniques. This approachudaddresses a number of limitations that are associated with alternative techniques.udA key part of this work was the development of sensor systems for a number ofudspecic applications. Sensor systems were developed for the following: real-timeudmeasurement of oxygen concentration in breath, measurement of dissolved oxygenudand dissolved carbon dioxide, and the simultaneous measurement of oxygen andudtemperature using a single sensor element.