Two kinds of electrochemical immunoassays for the tumor necrosis factor α in human serum using screen-printed graphite electrodes modified with poly(anthranilic acid)

We present two kinds of electrochemical immunoassays for the tumor necrosis factor α (TNF-α) which is a protein biomarker. The antibody against TNF-α was immobilized on a graphite screen-printed electrode modified with poly-anthranilic acid (ASPE). The first is based on impedimetry (and thus label-free) and the target antigen (TNF-α) is captured by the surface of the modified electrode via an immunoreaction upon which impedance is changed. This...