OPTIMIZED CAPACITIVE SENSOR FOR CHEMICAL ANALYSIS AND MEASUREMENT

摘要

An apparatus for detecting the presence and/or measuring the concentration of an analyte (24) in the fluid medium (22) is disclosed. The apparatus relies on biospecific binding between a biochemical binding system (20) and the analyte (24) to change the dielectric properties of a capacitive affinity sensor. The biological affinity sensor is optimized by: adjusting the thickness and dielectric properties of a passivation layer (16) to generally match the impedance of the biological binding system (20, 21); and minimize the double layer capacitance so that bulk capacitance changes associated with the biological binding system (20, 21) are maximized.