Electrochemiluminescent Immune-Modified Electrodes Based on Ag₂Se@CdSe Nanoneedles Loaded with Polypyrrole Intercalated Graphene for Detection of CA72‑4

This work described a new electrochemiluminescence (ECL) immunosensor based on polypyrrole intercalated graphene and Ag₂Se@CdSe nanoneedles. The novel nanomaterial Ag₂Se@CdSe, with needle-like morphology, was synthesized for the first time. The prepared Ag₂Se@CdSe nanoneedles exhibited good luminous performance in the presence of K₂S₂O₈. Polypyrrole intercalated amination graphene with high specific binding sites and excellent electrochemical performance was used as the platform for the sensor. The developed ECL immunosensor was used for the detection of CA72-4 with good linear relation in the range from 10^–4 to 20 U/mL and low detection limit of 2.1 × 10^–5 U/mL (S/N = 3). The developed ECL immunosensor with high sensitivity and spectral selectivity can be used for detection of real samples. Ag₂Se@CdSe nanoneedles could be promising candidate emitter for ECL biosensors in the future.