Detection of enzyme activities on Self-Assembled Monolayers

The work described in this thesis has the goal of detecting enzyme activity on a Self-Assembled Monolayer (SAM). This required the synthesis of novel chemical tools and biochemical evaluation of these tools on a surface. A solid phase synthesis of novel functionalised alkanethiol-oliogethyleneglycols (AT-OEGs) has been described. This methodology has allowed the synthesis of a variety of functionalised AT-OEGs, which can form SAMs which are functionalised with (bio)molecules. This synthesis was used to construct AT-OEGs conjugated to peptidic substrates of the enzymes thrombin and sortase and an AT-OEG which was conjugated to a redox probe, methylene blue. The AT-OEGs that are conjugated to sortase substrate peptides have been used to detect enzyme activity on a SAM. This system represents a model system, which can inform future studies on clinically relevant enzymes. The AT-OEGs that are conjugated to thrombin substrates have yet to be used to detect thrombin activity. The AT-OEG conjugated to methylene blue has been used in preliminary biosensing studies and could potentially be used as a novel mode of biosensing in the future.