Ag-Co3O4 @ Nr GO Material Synthesized by One-pot Hydrothermal Method for Carcinoembryonic Antigen (CEA) Detection of Enzyme-mimetic Electrochemical Immunosensor

A high-sensitivity carcinoembryonic antigen immunosensor was successfully prepared via a one-step hydrothermal method, wherein nitrogen-doped graphene oxide (Nr GO) loaded Ag and Co3O4 nanomaterials were synthesized using ammonia as the nitrogen source. Doping nitrogen atoms into the graphene structure forms a new type of N-type semiconductor with an increased number of graphene layers and more active sites for bonding with chemicals, thereby providing excellent in biocompatibility and good electrical conductivity. The electrical signal of the sensor is further amplified due to the good catalytic effect of Co3O4 and Ag NPs on H2O2. The signal probe requires neither pretreatment nor acid treatment, and can be easy to loaded with metal-immobilized antibodies, which greatly simplifies the detection step not shorten the detection time. The sensor has good sensitivity to detecting carcinoembryonic antigen (CEA) and can easily operate, and requires mild reaction conditions. Under optimal experimental conditions, the linear range of the sensor is 0.001-200 ng . mL(-1), the detection limit is 0.18 pg . mL(-1), and the linear correlation coefficient is 0.991, which can be used for CEA determination of the actual sample.