Study of a piezoelectric SAW immunosensor for the detection of alpha-fetoprotein

Piezoelectric biosensor combines the sensitivity of piezoelectric sensor and specificity of biological reaction. Compared with traditional biochemical assay, it has the features of simple structure, having no use of label and fast detection speed. In recent years, piezoelectric biosensor has been applied in the area of clinical analysis, biological technology and food sanitary detection. In this paper, we designed a piezoelectric immunosensor with SAW vibration mode. The measurements utilized the dual-channel system to eliminate noise environment. Here, the SAW biosensor was employed in the immune detection of alpha-fetoprotein (AFP), which was very important in clinical diagnosis. From the experimental results, we derived the quantitative relation between frequency shift and mass adsorption. The results also showed that the SAW immunosensor has good reproducibility, selectivity and sensitivity, and it must have good prospect in practical assay. © 2007 IEEE.