A Dual-Ion Synergistic Catalysis Utilizing Zn2+-Regulated CdSySe1–y ECL Immunosensor Employed for the Ultrasensitive CA19-9 DetectionClick to copy article link

Carbohydrate antigen 19-9 is a well-known malignancy biomarker, and its sensitive detection is particularly crucial in the diagnosis and assessment of pancreatic cancer. In this study, an ultrasensitive CA19-9 immunosensor was constructed using the Zn2+-regulated CdSySe1–y (Zn-CdSySe1–y) nanospheres (NSs) as the electrochemiluminescence (ECL) emitter and FeCoS2 nano octahedrons (NOs) as a coreactant enhancer. The microstructure of ternary transition metal chalcogenide CdSySe1–y was precisely tuned by Zn2+ doping to avoid aggregation and thus enable stable and efficient cathodic ECL responses. The bimetallic sulfide FeCoS2 was synthesized using a metal organic framework (MOF) as the template by ion permeation. It was able to catalyze the coreactant efficiently due to the synergistic effect of the Fe2+ and Co2+. The immunosensor exhibited low detection limit (7.6 × 10–5 U mL–1) in the wide linear range of 0.0001–100 U mL–1, offering a sensitive CA19-9 detection method.