Nanozyme-catalyzed dual-potential electrochemiluminescence immunosensor for simultaneous detection of CEA and NSE as lung cancer biomarkers.

Creating a dual-target detection system capable of independent signal output holds potential for enhancing the analytical reliability of biomarker detection, which may aid in early-stage cancer screening. Herein, a nanozyme-catalyzed dual-potential electrochemiluminescence (ECL) immunosensor was described for the simultaneous detection of lung cancer biomarkers: carcinoembryonic antigen (CEA) and neuron-specific enolase (NSE). Au-luminol functionalized CoFe2O4 nanoflowers (CoFe2O4@Au-luminol) served as the anodic probe, while CdS quantum dot-decorated hollow CeO2 nanospheres (CeO2@CdS QDs) constituted the cathodic probe. CoFe2O4 and CeO2 featuring multivalent elements (Co2+/3+, Fe2+/3+, Ce3+/4+), with their exceptional peroxidase (POD)-like activity, drove H2O2 co-reactant decomposition into abundant hydroxyl radicals (•OH) and superoxide anions (O2•-), thereby boosting dual-potential ECL signals. Changes in the ECL responses at two different excitation potentials allowed CEA and NSE to be determined on the nanozyme-assisted immunosensor surface, respectively. The assay exhibited a linear range of 0.005-100 ng/mL, with detection limits of 0.87 pg/mL for CEA and 0.41 pg/mL for NSE. The nanozyme-enhanced ECL biosensing platform, characterized by superior specificity, stability, and practicability, offers significant potential for detecting multiple biomarkers.