"Sensor-in-fibre" optical probes for molecular sensing in the gastrointestinal tract of murine models

Authors: Azzi, Victor
Advisor: Boudreau, DenisMarette, André
Abstract: Obesity and cardiometabolic diseases (CMD) are major public health issues among Canada’s northern population and throughout the world. It is believed that the exponential rise in CMD incidence is due to numerous environmental factors, which are driving important changes in the gut microbiome. This microbial community which populates our intestinal tract plays a key role in nutrient and energy metabolism, but can also drive pathogenic mechanisms when its interaction with the host is disrupted. This understanding has highlighted the lack of predictive tools and biomarkers for rapid and efficient diagnostic of various diseases within the medical field. Current analysis of the gut microbiota is mostly based on sequencing technologies to determine microbial composition and gene expression, while functional analyses are limited to surrogate markers of microbial activities through stool metabolites. The goal of this study is to develop a “Sensor-in-Fibre” probe with the capacity to detect key microbiome-derived molecules relevant to CMD pathogenesis in real time in vivo. The optical probe takes advantage of evanescent fields generated on its peripheral interface to excite species-selective surface-grafted sensing nanomaterials that have varying fluorescent properties based on the target molecules present in the surrounding environment. As a model system, FITC functionalized with (3-aminopropyl)triethoxysilane was grafted on the periphery of an optical fiber, leading to qualitative pH measurements revealed through fluorescence emission qualities. These measurements are possible due to the use of a mobile signal collection apparatus in conjunction with custom software made to enable a non-expert technician to use it. The experimental results demonstrate that, with the appropriate preparation, it is possible to quantitatively measure pH with this probe structure in vitro and preliminary studies suggest that the probe is also capable of measuring pH in vivo in real time.
Document Type: Mémoire de maîtrise
Issue Date: 2019
Open Access Date: 20 December 2019
Permalink: http://hdl.handle.net/20.500.11794/37631
Grantor: Université Laval
Collection:Thèses et mémoires

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