We have developed general, robust methodologies to wire up molecules into simple circuits on surfaces, using synthetic chemistry to modify and extend surface-bound molecular materials. We have demonstrated that the success of surface reactions can be probed at the single-molecule level using the scanning tunnelling microscope-based break-junction (STM-BJ) technique, by comparing the single-molecule conductance of molecules prepared in situ to the conductance of identical molecules prepared ex situ. Multiple different reactions, and even reversible, multi-step reactions have now been identified as suitable for modifying molecules in situ, where the STM-BJ has proved a remarkably sensitive and precise tool for surface analysis. Though efforts have been focused on thiol-based self-assembled monolayers on gold surfaces, they have also led us to explore the conductance of molecules terminated by other notable surface-binding linkers such as N-heterocyclic carbenes. To date, research supported by this fellowship has been disseminated through 7 articles in international, peer-review journals, as well as through presentation at over 10 scientific conferences and meetings.