Portable Immunosensor Based on Extended Gate--Field Effect Transistor for Rapid, Sensitive Detection of Cancer Markers

We present an immunosensor for the rapid and sensitive detection of the p53
oncosuppressor protein and of its mutated form p53R175H, which are both valuable cancer
biomarkers. The sensor is based on the accurate measurement of the source-drain current variation
of a metal oxide semiconductor field-effect transistor, as due to the gate potential changing arising
from charge release upon the selective capture of a biomarker by the partner immobilized on a
sensing surface connected to the gate electrode. A suitable microelectronic system is implemented
to combine high current resolution, which is needed to be competitive with standard
immunoassays, with compact dimensions of the final sensor device.