The design and development of a biosensor for monitoring the levels of the protein amylase in saliva using a novel design is described. The biosensor-sensing elements comprise of a layer of salivary antibodies immobilized onto a transducer by covalent attachment. Molecular recognition between the salivary antibody and antigen is monitored by the oxidation and reduction of an electroactive indicator. Biosensor characteristics are compared for solution-based and self-assembled electroactive indicators.