Label-free detection of p53 antibody using a microcantilever biosensor with piezoresistive readout

We report the detection of p53 antibody as a biomarker for early-stage cancer diagnosis using a microcantilever biosensor with piezoresistive readout. The accumulation of p53 antibody in human sera is found strongly involved in a variety of human cancers, thus simple and fast detection of the level of p53 antibody is of importance in clinical application. In this work, p53 antigen is immobilized on the surface of the microcantilever as a recognition probe to detect p53 antibody by measuring the deflection of the microcantilever using integrated piezoresistors, which is caused by the changes of the surface stress as a result of the specific bioaffinity between the antigen and the antibody. Quantitative detection of p53 antibody ranging from 20 ng/ml to 20 ¿g/ml has been achieved. Compared with conventional ELISA or immunofluorescene assay, the microcantilever sensor has the advantages of label-free operation, fast detection, and low cost.