A novel real-time immunoassay approach utilizing an electro-immunosensing microchip

This study was focused on the development of an electro-immunosensing (EIS) microchip for real-time measurement of antibody-antigen recognition in immunoassay. Instead of the enzyme conjugated with secondary antibody for detection, the process of electro-immunoassay was relatively simpler in comparison to the conventional enzyme-linked immunosorbent assay (ELISA). Based on the impedance variety in the frequency domain, we could successfully identify 1 ng/mL protein A with nonspecific antigen as the negative control. The EIS chip had higher sensitivity and shorter assay time than the ELISA. Furthermore, the EIS chip could detect the kinematics of antibody-antigen binding.