Self-Polarized Piezoelectric Biosensor Array for Multiple Immunoassys Applications

This paper reports a novel microfabricated self-polarized piezoelectric biosensor array for simultaneous detection of 3 different types of antigens. This array consists of 8 individual circular sensors with a diameter of 1 mm and self-polarization because of the stress accumulated in the piezoelectric membrane during the fabrication process. HBsAg, HBcAg and alpha-Fetoprotein (AFP) were immobilized onto sensing surface as the probe molecules. Due to the mass sensitive nature of these sensors, their resonant frequencies were depressed after the target anti-bodies were captured by the probe molecules. A clear frequency depression was observed and the mass sensitivity of the device is estimated to be about 4.80 Hz/ng. The preliminary results demonstrate that the developed piezoelectric biosensor array has potential applications for multiple immunoassays.