A sandwich-type electrochemical immunosensor for detecting CEA based on CeO2-MoS2 absorbed Pb2+

A sandwich-type immunosensor for detecting the concentration of carcinoembryonic antigen (CEA) was prepared. In this work, gold nanoparticles (Au NPs) were used as platform to attach more primary antibody (Ab(1)) due to excellent electrical conductivity and good biocompatibility. Molybdenum disulfide-Cerium oxide (CeO2-MoS2) nanohybrid was used as a carrier to absorb lead ions (Pb2+) and the second antibody (Ab(2)). CeO2-MoS2 Pb2+-Ab(2) was used as a nanoprobe to detect CEA antigen. Under optimal conditions, square wave voltammetry (SWV) successfully displayed the electrical signal of Pb2+. The designed electrochemical immunosensor has excellent analytical performance. In addition, the detection range was 0.001-80 ng/mL and the minimum detection limit was 0.3 pg/mL (S/N = 3), which had good selectivity and stability. Finally, the proposed immunosensor successfully detected the concentration of CEA in the serum of the sample, which provided a feasible method for CEA testing.