Affinity biosensors based on thin organic films on a metal microsystem support

Protein films (PF) on gold microsystem support were used for construction affinity biosensor for detecting human IgE. Antigen Q-SwaHU/IgE was bound with cysteamine or with cystramine-bovine serum albumin (BSA) complex by means of glutaraldehyde and immobilized to the thin gold support working electrode by means of chemisorption. The interaction of IgE with affinity biosensor has been detected by means of conductance. Addition of IgE to the electrolyte contained biosensor with BSA resulted in decrease membrane conductance, which that with BSA resulted in increase of sensor conductance in logarithm shape. in both cases the sensitivity of affinity biosensor was nM level. The mechanisms of biosensor response are discussed.