Projects have focused on identification of the methodology and design and synthesis of molecules for use in electrochemically based medical diagnostic assays incorporating ferrocene. Multifunctional ferrocenyl-fatty acid conjugates were designed and synthesised to establish the key properties required for use in biomolecular binding studies between fatty acids and human serum albumin. This powerful modular design strategy can be applied to other electrochemical probe systems in order to investigate biomolecular interactions.