Benzoxaboroles and Boronic Acids for Sensing Applications

Student thesis: Doctoral ThesisPhD

Abstract

All the work in this thesis is based on the boronic acid functionality, and its applications in different sensing systems.Chapter 1 introduces the concept of sensors. Different types of sensing mechanisms are introduced, and the applications of some chemical sensors are discussed. Boronic acids and esters have been widely employed in self-assembly and supramolecular chemistry, and the reversible binding of diols with boronic acids to form boronic esters has been exploited in the development of new chemical sensors for carbohydrates, including glucose. Boronic acid-containing molecules have found uses in a wide range of important sensing applications, including optical and electrochemical sensors for an array of biologically relevant materials. Benzoxaboroles, a distinct type of boronic acid with enhanced sugar binding properties, are also introduced.Chapter 2 describes the synthesis of a benzoxaborole-functionalised acrylamide monomer for applications in membrane separations. The high affinity of benzoxaboroles for the diol functionality has led to the utilisation of this functional group in many areas of materials chemistry. A new route to the benzoxaborole-functionalised monomer has been developed from readily available precursors. The new route is suitable for larger scale synthesis, giving the desired product in higher yields compared to previously published syntheses.Chapter 3 describes the use of a dye displacement assay for the detection of monosaccharides. A series of blank, benzoxaborole-functionalised and phenylboronic acid pinacol ester-functionalised hydrogels were prepared and their relative saccharide binding affinities were determined. The benzoxaborole-functionalised hydrogels showed enhanced binding affinity for all the reducing monosaccharide sugars studied. The enhanced binding to ᴅ-glucose is of particular importance, due its implications in type 2 diabetes, driving the need for new methods of detection for this particular sugar. The binding affinity of the hydrogels for non-reducing sugars is also investigated.Chapter 4 describes the synthesis and fluorescence properties of probes for the detection of hydrogen peroxide. Hydrogen peroxide is a member of a class of compounds called reactive oxygen species. Reactive oxygen species are important mediators in the pathological processes of many diseases including cerebral and cardiovascular diseases, inflammatory diseases, neurodegenerative diseases, diabetes and cancer. Because of the broad physiological and pathological consequences of these species, the development of new and better methods for their detection are required. A series of boronic acid pinacol ester probes were synthesised and analysed for their ability to detect hydrogen peroxide. The structure of the probes was altered using different substituents on the aromatic ring, and a novel oxazole probe was also synthesised.
Date of Award12 Jan 2018
LanguageEnglish
Awarding Institution
  • University of Bath
SupervisorTony James (Supervisor) & Steven Bull (Supervisor)

Cite this

Benzoxaboroles and Boronic Acids for Sensing Applications
Lampard, E. (Author). 12 Jan 2018

Student thesis: Doctoral ThesisPhD