A carcinoembryonic antigen optoelectronic immunosensor based on thiol-derivative-nanogold labeled anti-CEA antibody nanomaterial and gold modified ITO

A dual carcinoembryonic antigen (CEA) biosensing alternative optoelectric platforms has been developed based on gold modified ITO electrode. The new platform is constructed by assembly of a thiol-derivative-nanogold (TDN) labeled anti-CEA (TDN-anti-CEA) antibody on a gold/indium tin oxide (ITO) electrode to create a high CEA sensitive surface. The gold film deposited on ITO glass provides a desirable substrate for the immobilization of the TDN-anti-CEA antibody and improves the compatibility between nanogold and electrode which results in a significant amplification. By using the same TDN-anti-CEA antibody probe, the CEA (analyte) was analyzed using two different methods; electrochemical impedance spectroscopy (EIS) and ultraviolet (UV) spectroscopy, the results showed that the limit of detection was 1 and 2 pg/ml by EIS and UV methods, respectively. Given their promising advantages, it is likely that dual platforms will evolve to be an attractive tool for use in many different fields.