Applications of Anion Binding

This thesis describes the development and exploration of chemosensing systems for phosphates and their applications to specific biological challenges. Investigation of the sensing abilities of a peptide-based bis-Zn(DPA) chemosensor, is detailed. Building on existing research aimed at developing selective sensors of phosphate species (PPi, ADP and ATP), the properties of this sensor were thoroughly investigated in a variety of buffered aqueous systems. The chemosensor exhibited a large, selective, turn on in emission in the presence of pyrophosphate but this response was modulated by additives including magnesium(II) and calcium(II) that are commonly found in biological systems. However, a range of conditions were identified that allowed the sensor to be successfully applied to the challenge of monitoring multiple enzymatic reactions. Cross reactive chemosensors are discussed and applied to discriminate between multiple similar phosphate species including inorganic, nucleoside phosphates and phosphorylated amino acids. Using two array-based sensing approaches and two different methods for diversification of array elements, the sensing of phosphates in an array format was investigated. The resultant arrays represent an improvement on the breadth of phosphates previously classified using an array-based sensing approach. Finally, the principles of selective and cross reactive chemosensors are combined to address a diagnostic challenge – diagnosis of rheumatological disease. By targeting pyrophosphate and uric acid, a strategy to diagnose crystal arthritis was developed. Proof of concept studies showed promising results however challenges remain for the analysis of clinical samples. The work in Chapter 4 was affected by the Covid-19 pandemic and details of further planned studies are included