Label-free protein assay with site-directly immobilized antibody using self-actuating PZT cantilever

This paper reports a label-free detection of myoglobin using microfabricated self-actuating PZT cantilever. Electrical detection of antibody-antigen interaction on the surface was achieved through measuring the resonant frequency of cantilever. On Au surface of cantilever, biotinylated antibody bound to the streptavidin layer. We immobilized site-directed antibody through reducing the binding region to hinge region, which resolves the random arrangement of the biotinylated antibody and increases the number of binding complexes. This protocol enhanced the performance of analytical sensitivity about ten times, and the experimental results demonstrated this biosensor can be used for diagnosis of acute myocardial infarction in clinical range of tens of ng/ml.