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Title: Development of luminescent labels for use in miniaturised diagnostic devices
Author: Edwards, Angharad Naomi
ISNI:       0000 0004 2724 147X
Awarding Body: Imperial College London
Current Institution: Imperial College London
Date of Award: 2012
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As scientific and technological advances impact on medical care, there has been a specific demand for low-cost, miniaturised diagnostic devices for use in GP surgeries and in the home. These so-called point-of-care (POC) technologies have been hailed as important for the future of medical treatment, not only in the developed world but also in the developing world where a highly portable format of diagnostic technology could revolutionise treatment methods. Removing the need for patient samples to be sent away for laboratory analysis speeds up the diagnosis procedure and allows for more immediate treatment, leading to greatly improved recovery rates for time-critical diseases. Many current POC devices utilise luminescence-based bioassays owing to their high sensitivity and quantitative capabilities and there is an urgent demand for new high performance luminescent labels suitable for use in these integrated bioassay technologies. Advances in organic light emitting materials along with microfluidic technologies have added to the promise of developing low-cost POC devices. This work has focussed on two promising long-lived, highly luminescent compounds: a ruthenium(II) complex and an inorganic silicate. Surface modification studies and size analysis of the inorganic silicate particles were carried out and the resulting photophysical properties assessed. Ruthenium dye-doped polymer beads were prepared using a facile precipitation method and a number of different polymer encapsulants tested. The effect of encapsulation on the photophysical properties of the dye was investigated and time-gated detection studies performed on the optimal beads. Luminescence lifetime measurements and SEM imaging were also used to characterise the particles. This work represents the first known use of polystyrene/ bisphenol A diglycidyl ether as a host matrix for luminophores to form highly photostable beads readily excited by low cost LEDs.
Supervisor: de Mello, John Sponsor: Engineering and Physical Sciences Research Council ; Molecular Vision Ltd
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral