A CMOS capacitive biosensor array for highly sensitive detection of pathogenic avian influenza DNA

This work presents a CMOS capacitive biosensor array for detection of the pathogenic avian influenza virus DNA. Sensing resolution is significantly enhanced by monolithic integration to reduce the parasitic effect and the use of a thin dielectric layer as the sensing interface. The array contains both planar and interdigitated electrode designs with the same CMOS readout to compare their sensing capabilities. Both designs show highly sensitive detection. The interdigitated electrode design shows more sensitive detection with a larger capacitance change, illustrating a limit of detection near 10 aM level. Detection of the hepatitis B virus DNA is also demonstrated to show similar detection limit.