Ultrasensitive Electrochemical Immunosensor For The Direct Detection Of CEA Based On A Hollow Nanobox-MOFs/AuPtRu Nanocomposites Modified RGO-TEPA

In this study,a novel direct method electrochemical immunosensor was developed for ultra-sensitive quantitative determination of CEA.The rGO-TEPA/HNMs/AuPtRu nanocomposites was synthesized for the first time and applied in the electrochemical immunosensor,combined with the biotin-streptavidin protein system to double-amplify the sensor signal.Combine aminated reduced graphene oxide-tetraethylenepentamine（rGO-TEPA）with hollow nanobox-MOFs（HNMs）encapsulated with AuPtRu TNPs on the surface to synthesize rGO-TEPA/HNMs/AuPtRu nanocomposite material,used as a base material for sensor manufacturing.The nanocomposites can be used as an ideal carrier platform for the immobilization of streptavidin（SA）due to its good biocompatibility,strong catalytic ability of H₂O₂,large specific surface area and large amount of modified amino groups.Therefore,they are further used to immobilize more biotin modified antibodies（Bio-Ab）,which can enhance the difference between the electrochemical signal following antibody-antigen specific recognition,thus increasing the sensitivity of the constructed immunosensor.Under the best experimental conditions,the electrochemical immunosensor exhibits high sensitivity(with a lower detection limit of 36.44 fg·mL^-1),good reproduction and stability,high specificity,and wide detection range(0.1 pg·mL^-1to 1μg·mL^-1).Meanwhile,the immunosensor was applied to the detection of CEA in human serum.This article puts forward the conclusion that this extra-sensitive immunosensor can be used in CEA detection in early clinical tumor diagnosis.