An electrochemiluminescence immunosensor based on ZnSe@ZnS QDs composite for CEA detection in human serum

[email protected] QDs were synthesized by a simple one-step method. The prepared [email protected] quantum dots ( [email protected] QDs) composite showed a strong cathode ECL emission using potassium persulfate (K 2 S 2 O 8 ) as a co-reactant. The poly-(diallyldimethylammonium chloride) (PDDA) reduced graphene oxide (PDDA-rGO) composite provided a larger activity site could conjugate more [email protected] QDs and second antibody (Ab 2 ) to improve the sensitivity of the ECL immunosensor. The electrode modified with Au NPs was employed for immobilization of primary antibodies (Ab 1 ) and enhancing the electronic transmission rate of the immunosensor. A novel ECL immunosensor was constructed using Au NPs as a sensing platform and PDDA-rGO/ [email protected] QDs composite as signal probe for highly-sensitive carcinoembryonic antigen (CEA) detection in human serum. Under optimal conditions, a range of 0.0001–100   ng/mL and the detection limit of 0.029   pg/mL for CEA were obtained. This ECL immunosensor possesses long-term stability, good reproducibility and high sensitivity. These are promising qualities for detecting biomarkers, drugs, and environmental pollutants .