The use of impedance spectroscopy for the characterization of protein-modified ISFET devicesaa:Application of the method for the analysis of biorecognition processes

摘要

Impedance spectroscopy is used to characterize the structure of biomaterial layers on the gate surface of ISFET devices,and toelucidate antigen-antibody binding interactions on the gate interface.The method is based on the redording of the transferfunction o fthe systemas a function of frequency and on the extraction of the respective #tau#_1 and#tau#_2 values of the systems.From the experimental values,thefilm thicknesses of the respective proteinlayers are estimated.The method is applied to elucidate the structures of a glucose oxidase,GOx,umltilayer assembly,and of a di-biotin-cross-linked avidin multilayer system.The method is also used to sense the dinitrophenyl antibody by following the formation of the antigen-antibody complex on the gate surface.