*1.2.1 Selectivity*

This is usually the most important feature of a biosensor. A bioreceptor detects a specific analyte in a sample containing other admixtures and contaminants. The interaction of an antigen with the antibody depicts an example of this selectivity of a biosensor. Antibodies act as bioreceptors and are immobilized on the surface of the transducer. A solution (usually a buffer containing salts) containing the antigen is then exposed to the transducer where antibodies interact only with the antigens [2].
