Detection of avian influenza virus H9N2 based on self-driving and self-sensing microcantilever piezoelectric sensor

In this article, we used the self-excitation and self-inductance characteristics of polyvinylidene fluoride (PVDF) piezoelectric materials, combined with the powerful signal processing and calculation analysis capabilities of integrated circuits, for the first time to explore a set of microcantilever sensor "readout system" without additional driver (self-driving) and can realize self-sensing external signal (self-sensing). It was successfully applied to the unlabeled detection of avian influenza virus (AIV) H9N2. The specific force of the antigen-antibody complexes on the surface of the microcantilever leads to the change of the stress of the cantilever, which drives the constructed detection device, and does not require an additional excitation source to drive it, that is, the self-driving part. At the same time, due to the movement of piezoelectric charges in the film caused by the positive piezoelectric effect of the PVDF film, self-inductive charges are generated on the surface of the sensor dielectric. The charge signal is converted into a voltage signal, and the sensing part is completed, that is, self-sensing. The immunosensor has a linear range of 100-1000 ng/mL with a detection limit of 2.9 ng/mL. The method will also open up a new avenue for the detection of other analytes based on antigen-antibody responses.